Tags:

• :boom: [Breaking Change]
• :eyeglasses: [Spec Compliance]
• :rocket: [New Feature]
• :bug: [Bug Fix]
• :memo: [Documentation]
• :nail_care: [Polish]
• :house: [Internal]

13.0.0-alpha.5 (Unreleased)

:boom: Breaking Change

• Make Jsx.component abstract. https://github.com/rescript-lang/rescript/pull/8390
• Drop Node.js version 20.x support, as it is reaching EOL. https://github.com/rescript-lang/rescript/pull/8401

:eyeglasses: Spec Compliance

:rocket: New Feature

:bug: Bug fix

• Fix directive @warning("-102") not working. https://github.com/rescript-lang/rescript/pull/8322
• Fix duplicated comments in for..of formatter. https://github.com/rescript-lang/rescript/pull/8395
• Fix issue where warning 56 would blow up with dict{} patterns. https://github.com/rescript-lang/rescript/pull/8403
• Acquire rewatch build lock before initialization. https://github.com/rescript-lang/rescript/pull/8409
• Close remaining rewatch build.lock gaps. https://github.com/rescript-lang/rescript/pull/8410
• Rewatch: treat transitive workspace dependencies as local packages in monorepo roots. https://github.com/rescript-lang/rescript/pull/8411

:memo: Documentation

:nail_care: Polish

• Improve default argument type mismatch errors. https://github.com/rescript-lang/rescript/pull/8389
• Resolve workspace dependencies in editor analysis. https://github.com/rescript-lang/rescript/pull/8392
• Build system: Add OpenTelemetry tracing support for cli commands. https://github.com/rescript-lang/rescript/pull/8370
• Use a single vendored @rescript/react package across the repo. https://github.com/rescript-lang/rescript/pull/7525
• Improve deprecated attribute extraction and support record form. https://github.com/rescript-lang/rescript/pull/8396

:house: Internal

• Remove Primitive_option.toUndefined; use valFromOption for optional ffi args. https://github.com/rescript-lang/rescript/pull/8380

13.0.0-alpha.4

:boom: Breaking Change

• Support for break and continue in loops. break and continue are new keywords. https://github.com/rescript-lang/rescript/pull/8348
• Fix iterator / iterable typedefs, add generator typedefs. https://github.com/rescript-lang/rescript/pull/8355
• Remove deprecated %external extension. https://github.com/rescript-lang/rescript/pull/8376
• Remove Belt API functions returning undefined<'a> (e.g., Belt.Array.getUndefined). Functions returning option<'a> should be used instead (e.g., Belt.Array.get). https://github.com/rescript-lang/rescript/pull/8377

:rocket: New Feature

• Implement for...of and for await...of loops. https://github.com/rescript-lang/rescript/pull/7887
• Add support for dict spreads: dict{...foo, "bar": 2, ...qux}. https://github.com/rescript-lang/rescript/pull/8369
• Rewatch: add --prod flag to build, watch, and clean to skip dev-dependencies and dev sources ("type": "dev"), enabling builds in environments where dev packages aren't installed (e.g. after pnpm install --prod). https://github.com/rescript-lang/rescript/pull/8347
• Rewatch: feature-gated source directories. Tag a source entry with "feature": "<name>" and select with --features a,b (or per-dep in dependencies / dev-dependencies) to include optional slices of a package's source tree at build time. Top-level features map supports transitive implications. https://github.com/rescript-lang/rescript/pull/8379
• Rewatch: improve watch output and add --clear-screen option. https://github.com/rescript-lang/rescript/pull/8373
• Add Dict.assignMany, Dict.concat, Dict.concatMany, Dict.concatAll, Array.concatAll to the stdlib. https://github.com/rescript-lang/rescript/pull/8364

:bug: Bug fix

• Fix partial application generalization for .... https://github.com/rescript-lang/rescript/pull/8343
• Rewatch: preserve warnings after atomic-save full rebuilds. https://github.com/rescript-lang/rescript/pull/8358
• Preserve JSX prop locations across the AST0 translation layer, fixing 0:0 editor diagnostics in PPX-related flows. https://github.com/rescript-lang/rescript/pull/8350
• Fix type lowering for dict{} and async, so you don't need to annotate one extra time when the type is known. https://github.com/rescript-lang/rescript/pull/8359
• Rewatch: don't suppress progress messages under -v/-vv. https://github.com/rescript-lang/rescript/pull/8371
• Rewatch: print 'Finished compilation' in watch plain output mode. https://github.com/rescript-lang/rescript/pull/8372

:nail_care: Polish

• Allow builds while watchers are running. https://github.com/rescript-lang/rescript/pull/8349
• Rewatch: restore backward compatibility for bsconfig.json. https://github.com/rescript-lang/rescript/pull/8368
• Restore parsing of the legacy (. ...) uncurried syntax for backwards compatibility with libraries still on older ReScript versions; emit a deprecation warning when it is used. Rewatch also surfaces this specific deprecation when it originates from an external dependency so users can report breakage upstream. https://github.com/rescript-lang/rescript/pull/8383
• Rewatch: replace wave-based compile scheduler with a work-stealing DAG dispatcher ordered by critical-path priority, avoiding the per-wave stall on the slowest file. https://github.com/rescript-lang/rescript/pull/8374

:house: Internal

• Move rescript.json reading out of bsc into rewatch; remove the custom OCaml JSON parser. https://github.com/rescript-lang/rescript/pull/8365

13.0.0-alpha.3

:boom: Breaking Change

• Change Intl.Collator.compare return type from int to Ordering.t (float). https://github.com/rescript-lang/rescript/pull/8289

:rocket: New Feature

• Reanalyze: add glob pattern support for suppress/unsuppress configurations (e.g., "src/generated/**"). https://github.com/rescript-lang/rescript/pull/8277
• Add optional ~locales and ~options parameters to String.localeCompare. https://github.com/rescript-lang/rescript/pull/8287
• Support inline records in external definitions. https://github.com/rescript-lang/rescript/pull/8304

:bug: Bug fix

• Reanalyze server: invalidate cache and recompute results when config changes in rescript.json. https://github.com/rescript-lang/rescript/pull/8262
• Fix null and array values incorrectly matching the Object branch when pattern matching on JSON.t (or other untagged variants with an Object case) in statement position. https://github.com/rescript-lang/rescript/pull/8279
• Fix rewatch panic when package.json has no name field. https://github.com/rescript-lang/rescript/pull/8291
• Fix unpacking first-class module in default argument of React component. https://github.com/rescript-lang/rescript/pull/8296
• Fix exception record field regression. https://github.com/rescript-lang/rescript/pull/8319
• Rewatch: ignore stale lock for unrelated process name. https://github.com/rescript-lang/rescript/pull/8316
• Fix handling of exotic identifiers for let bindings in GenType. https://github.com/rescript-lang/rescript/pull/8315

:nail_care: Polish

• Improve error message for dependency without rescript.json. https://github.com/rescript-lang/rescript/pull/8292

:house: Internal

• Reanalyze server: redesign incremental fixpoint with delete-then-rederive strategy and predecessor tracking, improving speed on deletions. https://github.com/rescript-lang/rescript/pull/8276
• Fix build tests failing silently. https://github.com/rescript-lang/rescript/pull/8295

13.0.0-alpha.2

:bug: Bug fix

• Fix compiler crash (Fatal error: Parmatch.all_record_args) when matching empty dict/record patterns. https://github.com/rescript-lang/rescript/pull/8246
• Fix null falling into the object branch instead of the wildcard when pattern matching on untagged variants with both Object and null cases. https://github.com/rescript-lang/rescript/pull/8253

:nail_care: Polish

• Build system: Watch only source folders from build state instead of the entire project directory, and report missing configured source folders. https://github.com/rescript-lang/rescript/pull/8219

:house: Internal

• Speed up dev container test by installing OCaml in docker image instead of in postCreate.sh. https://github.com/rescript-lang/rescript/pull/8230

13.0.0-alpha.1

:boom: Breaking Change

• Remove the legacy build system. Going forward, only the modern build system is supported, and the rescript-legacy command is not available anymore. https://github.com/rescript-lang/rescript/pull/8186 https://github.com/rescript-lang/rescript/pull/8212
• Remove support for bsconfig.json. https://github.com/rescript-lang/rescript/pull/8187
• Int.fromString and Float.fromString use stricter number parsing and no longer use an explicit radix argument, but instead support parsing hexadecimal, binary and exponential notation. https://github.com/rescript-lang/rescript/pull/8129
• Remove the deprecated module system names es6 and es6-global (superseded by esmodule). https://github.com/rescript-lang/rescript/pull/8205
• Default to module system esmodule. https://github.com/rescript-lang/rescript/pull/8213
• Remove external-stdlib configuration option from rescript.json. This option was rarely used and is no longer supported. https://github.com/rescript-lang/rescript/pull/8175
• Remove the deprecated uncurried (. args) => ... function syntax. https://github.com/rescript-lang/rescript/pull/8211
• js-post-build now passes the correct output file path based on in-source configuration: when in-source: true, the path next to the source file is passed; when in-source: false, the path in the lib/<module>/ directory is passed. Additionally, stdout and stderr from the post-build command are now logged. https://github.com/rescript-lang/rescript/pull/8190
• js-post-build command now runs in the directory containing the rescript.json where it is defined, instead of the unpredictable build invocation directory. This provides consistent behavior in monorepos. https://github.com/rescript-lang/rescript/pull/8195
• Remove support for deprecated bs-dependencies, bs-dev-dependencies, and bsc-flags configuration options. Use dependencies, dev-dependencies, and compiler-flags instead. https://github.com/rescript-lang/rescript/pull/8196
• bsc: remove legacy -uncurried flag. https://github.com/rescript-lang/rescript/pull/8201
• Remove deprecated cli flags --dev, --create-sourcedirs and build -w. https://github.com/rescript-lang/rescript/pull/8202
• Do not allow two different package specs with the same suffix to avoid conflicts. https://github.com/rescript-lang/rescript/pull/8214

:rocket: New Feature

• Reanalyze: add scoped @@live/@@dead annotations for marking module/file sections as live or dead. https://github.com/rescript-lang/rescript/pull/8197
• Stdlib: Added Array.zip, Array.unzip, Array.zipBy, and Array.partition. https://github.com/rescript-lang/rescript/pull/8244

:bug: Bug fix

• Reanalyze: fix reactive/server stale results when cross-file references change without changing dead declarations (non-transitive mode). https://github.com/rescript-lang/rescript/pull/8173
• Reanalyze: link record/variant label liveness across type re-exports (type y = x = {...}). https://github.com/rescript-lang/rescript/pull/8217
• Add duplicate package detection to rewatch. https://github.com/rescript-lang/rescript/pull/8180
• Rewatch: do not warn about "reanalyze" config field. https://github.com/rescript-lang/rescript/pull/8181
• Fix error when importing CommonJS runtime modules with require(). https://github.com/rescript-lang/rescript/pull/8194
• Rewatch: fix warnings from non-recompiled modules being lost during incremental builds in watch mode. https://github.com/rescript-lang/rescript/pull/8216

:nail_care: Polish

• Formatter no longer writes files when contents are already correctly formatted. https://github.com/rescript-lang/rescript/pull/8209
• Build system: Only log verbose "Generating AST for module" when actually parsing. https://github.com/rescript-lang/rescript/pull/8210

12.1.0

:rocket: New Feature

• Add support for Set, Map, WeakSet and WeakMap to @unboxed. https://github.com/rescript-lang/rescript/pull/8009
• Reanalyze: add reactive incremental analysis (-reactive, -runs, -churn) and Mermaid pipeline dumping (-mermaid). https://github.com/rescript-lang/rescript/pull/8092
• Reanalyze: add reanalyze-server (long-lived server) with transparent delegation for rescript-tools reanalyze -json. https://github.com/rescript-lang/rescript/pull/8127
• Add support of js-post-build in Rewatch. Note that ${file} is now an absolute path. https://github.com/rescript-lang/rescript/pull/8151

:bug: Bug fix

• Fix rewatch swallowing parse warnings (e.g., for %todo). https://github.com/rescript-lang/rescript/pull/8135
• Rewatch: log errors and warnings to stderr. https://github.com/rescript-lang/rescript/pull/8147 https://github.com/rescript-lang/rescript/pull/8148
• Rewatch: warn about deprecated package specs es6/es6-global. https://github.com/rescript-lang/rescript/pull/8146
• Fix formatter removing doc comments for polymorphic variants. https://github.com/rescript-lang/rescript/pull/8155

:nail_care: Polish

• Rewatch: enable --create-sourcedirs by default (now deprecated when explicitly used). https://github.com/rescript-lang/rescript/pull/8092
• Rewatch: check if filename case for interface and implementation matches. https://github.com/rescript-lang/rescript/pull/8144

12.0.2

:rocket: New Feature

:bug: Bug fix

• Reanalyze: make optional args analysis liveness-aware, preventing false positives when functions are only called from dead code. https://github.com/rescript-lang/rescript/pull/8082

• Fix: do not warn for "editor" field in rescript.json. https://github.com/rescript-lang/rescript/pull/8084

• Fix @val shadowing (rewrite using globalThis). https://github.com/rescript-lang/rescript/pull/8098

• Fix @scope shadowing (rewrite using globalThis). https://github.com/rescript-lang/rescript/pull/8100

• Formatter: normalize underscore placeholders in pipe expressions to canonical form (e.g., a->map2(_, fn) formats to a->map2(fn)). https://github.com/rescript-lang/rescript/pull/8033

• Fix rewatch panic on duplicate module name. https://github.com/rescript-lang/rescript/pull/8102

• Fix let? unwrap to use actual variable names from pattern instead of hardcoded "x"/"e". https://github.com/rescript-lang/rescript/issues/8085

• Fix "Ill-formed list of warnings" errors for PPXs with rescript-legacy. https://github.com/rescript-lang/rescript/pull/8103

• Fix gentype generating invalid syntax for exotic / escaped record field names and type names. https://github.com/rescript-lang/rescript/pull/8087

• Formatter: Improve multiline printing of record types and values. https://github.com/rescript-lang/rescript/pull/7993

:house: Internal

• Reanalyze: refactor DCE to pure pipeline architecture for order-independence and incremental update support. https://github.com/rescript-lang/rescript/pull/8043

12.0.1

:bug: Bug fix

• Fix exponential compilation blowup with large unboxed variants and dict pattern matching. https://github.com/rescript-lang/rescript/pull/8078
• Rewatch: warnings for unsupported/unknown rescript.json fields. https://github.com/rescript-lang/rescript/pull/8031
• Fix missing ignore function in some Stdlib modules. https://github.com/rescript-lang/rescript/pull/8060
• Fix signature matching for externals when abstract alias hides function arity. https://github.com/rescript-lang/rescript/pull/8045
• Fix arity detection for arrows returning nested generics. https://github.com/rescript-lang/rescript/pull/8064
• Fix error handling when rescript.json parsing fails and improve error message. https://github.com/rescript-lang/rescript/pull/8067
• Fix invalid JSX being generated for empty fragments. https://github.com/rescript-lang/rescript/pull/8077

:nail_care: Polish

• Add missing deprecation and migration for Exn.Error. https://github.com/rescript-lang/rescript/pull/8036

12.0.0

No changes compared to rc.5.

12.0.0-rc.5

:bug: Bug fix

• Fix printing of tagged template literals. https://github.com/rescript-lang/rescript/pull/8018
• Fix printing of optional record fields in pattern matching errors. https://github.com/rescript-lang/rescript/pull/8019

:house: Internal

• Editor: resolve @rescript/runtime via environment variable RESCRIPT_RUNTIME. https://github.com/rescript-lang/rescript/pull/8023
• Remove leftovers from @meth attribute. https://github.com/rescript-lang/rescript/pull/8022

12.0.0-rc.4

:boom: Breaking Change

• Fix some Intl bindings (Intl.Collator.supportedLocalesOf, Intl.DateTimeFormat.supportedLocalesOf, Intl.ListFormat.supportedLocalesOf, Intl.NumberFormat.supportedLocalesOf, Intl.PluralRules.supportedLocalesOf, Intl.RelativeTimeFormat.supportedLocalesOf, Intl.Segmenter.supportedLocalesOf) which return array<string> and not their corresponding main type t. Also remove Intl.PluralRules.selectBigInt and Intl.PluralRules.selectRangeBigInt which don't work in many JS runtimes. https://github.com/rescript-lang/rescript/pull/7995

:bug: Bug fix

• Fix fatal compiler error that occurred when an %ffi extension point contained invalid JavaScript. https://github.com/rescript-lang/rescript/pull/7998

:nail_care: Polish

• Dedicated error messages for old Reason array literal syntax ([| and |]), and for the old pipe (|>). Primarly intended to help LLMs that might try to use old code patterns. https://github.com/rescript-lang/rescript/pull/8010

:house: Internal

• Rename Core to Stdlib in tests/tests. https://github.com/rescript-lang/rescript/pull/8005
• CI: Build on windows-2025 runners. https://github.com/rescript-lang/rescript/pull/8006
• Rewatch: upgrade Rust to 1.91.0. https://github.com/rescript-lang/rescript/pull/8007

12.0.0-rc.3

:bug: Bug fix

• Fix @directive on function level with async and multiple parameters. https://github.com/rescript-lang/rescript/pull/7977
• Fix fatal error for external with @as. https://github.com/rescript-lang/rescript/pull/7978

:nail_care: Polish

• Rewatch: plain output when not running in tty. https://github.com/rescript-lang/rescript/pull/7970
• Streamline rewatch help texts. https://github.com/rescript-lang/rescript/pull/7973
• Rewatch: Reduced build progress output from 7 steps to 3 for cleaner, less verbose logging. https://github.com/rescript-lang/rescript/pull/7971

:house: Internal

• Clean up usage of Ast_uncurried helpers. https://github.com/rescript-lang/rescript/pull/7987

12.0.0-rc.2

:boom: Breaking Change

• Replace binary operators with F#-style ~~~, ^^^, &&&, |||. https://github.com/rescript-lang/rescript/pull/7894

:bug: Bug fix

• Fix: use configured Jsx module for constraining component return type. https://github.com/rescript-lang/rescript/pull/7945
• Undeprecate Js_OO module since it is still used with the @this attribute. https://github.com/rescript-lang/rescript/pull/7955
• Fix crash when using bitwise not (~~~) on an incompatible type. https://github.com/rescript-lang/rescript/pull/7965

:house: Internal

• JSX PPX: use React.component instead of React.componentLike for externals. https://github.com/rescript-lang/rescript/pull/7952

12.0.0-rc.1

:nail_care: Polish

• Improve circular dependency errors, and make sure they end up in the compiler log so the editor tooling can surface them. https://github.com/rescript-lang/rescript/pull/7940
• JSX PPX: add Jsx.element return constraint. https://github.com/rescript-lang/rescript/pull/7939

:house: Internal

• Use AST nodes with locations for fn arguments in the typed tree. https://github.com/rescript-lang/rescript/pull/7873

12.0.0-beta.14

:boom: Breaking Change

• Removed rescript legacy subcommand in favor of separate rescript-legacy binary. https://github.com/rescript-lang/rescript/pull/7928
• Add comparison function for Error in Result.equal and compare. https://github.com/rescript-lang/rescript/pull/7933
• Rewatch: "type": "dev" and dev-dependencies will be compiled by default for local packages. The --dev flag no longer does anything. https://github.com/rescript-lang/rescript/pull/7934

:bug: Bug fix

• Prevent lockfile creation when project folder is missing. https://github.com/rescript-lang/rescript/pull/7927
• Fix parameter type / return type ambiguity error for unit case. https://github.com/rescript-lang/rescript/pull/7930

:nail_care: Polish

• ReScript cli: do not show build command options in the root help. https://github.com/rescript-lang/rescript/pull/7715
• Deprecate reanalyze @raises in favor of @throws. https://github.com/rescript-lang/rescript/pull/7932

:house: Internal

• CI: run macOS builds on macOS 15. https://github.com/rescript-lang/rescript/pull/7935

12.0.0-beta.13

:bug: Bug fix

• Fix result examples. https://github.com/rescript-lang/rescript/pull/7914
• Make inline record fields that overlap with a variant's tag a compile error. https://github.com/rescript-lang/rescript/pull/7875

:nail_care: Polish

• Keep track of compiler info during build. https://github.com/rescript-lang/rescript/pull/7889
• Improve option optimization for constants. https://github.com/rescript-lang/rescript/pull/7913
• Option optimization: do not create redundant local vars. https://github.com/rescript-lang/rescript/pull/7915
• Js output: remove superfluous newline after every if. https://github.com/rescript-lang/rescript/pull/7920
• Rewatch: Traverse upwards for package resolution in single context projects. https://github.com/rescript-lang/rescript/pull/7896
• Rewatch: Add --warn-error flag to build. https://github.com/rescript-lang/rescript/pull/7916

12.0.0-beta.12

:boom: Breaking Change

• Make experimental-features kebap-case in compiler config like the other fields. https://github.com/rescript-lang/rescript/pull/7891

:rocket: New Feature

• Add littleEndian feature for DataView to Stdlib. https://github.com/rescript-lang/rescript/pull/7881
• Add mapOkAsync, mapErrorAsync, flatMapOkAsync and flatMapErrorAsync for async results to Stdlib. https://github.com/rescript-lang/rescript/pull/7906

:bug: Bug fix

• Include -runtime-path as bsc argument when generating .mlmap file. https://github.com/rescript-lang/rescript/pull/7888

:nail_care: Polish

• Add (dev-)dependencies to build schema. https://github.com/rescript-lang/rescript/pull/7892
• Dedicated error for dict literal spreads. https://github.com/rescript-lang/rescript/pull/7901
• Dedicated error message for when mixing up : and = in various positions. https://github.com/rescript-lang/rescript/pull/7900

12.0.0-beta.11

:boom: Breaking Change

• Have String.charCodeAt return option<int>; add String.charCodeAtUnsafe. https://github.com/rescript-lang/rescript/pull/7877
• Remove support of JSX children spread. https://github.com/rescript-lang/rescript/pull/7869

:rocket: New Feature

• Add Array.filterMapWithIndex to Stdlib. https://github.com/rescript-lang/rescript/pull/7876

:bug: Bug fix

• Fix code generation for emojis in polyvars and labels. https://github.com/rescript-lang/rescript/pull/7853
• Add reset to experimental_features to correctly reset playground. https://github.com/rescript-lang/rescript/pull/7868
• Fix crash with @get on external of type unit => 'a. https://github.com/rescript-lang/rescript/pull/7866
• Fix record type spreads in inline records. https://github.com/rescript-lang/rescript/pull/7859

:nail_care: Polish

• Reactivate optimization for length of array literals. https://github.com/rescript-lang/rescript/pull/7872
• Float.isNaN: use Number.isNaN instead of global isNaN. https://github.com/rescript-lang/rescript/pull/7874

:house: Internal

• Playground: Add config options for experimental features and jsx preserve mode. https://github.com/rescript-lang/rescript/pull/7865
• Clean up tests. https://github.com/rescript-lang/rescript/pull/7861 https://github.com/rescript-lang/rescript/pull/7871
• Add -runtime-path flag to bsc (and bsb), we are detecting the location of @rescript/runtime in cli/rescript.js based on runtime module resolution. https://github.com/rescript-lang/rescript/pull/7858

12.0.0-beta.10

:rocket: New Feature

• Support mapping more standard library types automatically to TS types via gentype, without requiring shims. https://github.com/rescript-lang/rescript/pull/7842

:bug: Bug fix

• Show Stdlib.TypedArray completions for typed arrays. https://github.com/rescript-lang/rescript/pull/7827
• Show Stdlib.Null and Stdlib.Nullable completions for Stdlib.null<'a> and Stdlib.nullable<'a> types, respectively. https://github.com/rescript-lang/rescript/pull/7826
• Fix generation of interfaces for module types containing multiple type constraints. https://github.com/rescript-lang/rescript/pull/7825
• JSX preserve mode: fix "make is not a valid component name". https://github.com/rescript-lang/rescript/pull/7831
• Rewatch: include parser arguments of experimental features. https://github.com/rescript-lang/rescript/pull/7836
• Stop mangling tagged templates and backquoted strings. https://github.com/rescript-lang/rescript/pull/7841
• JSX v4: fix arity mismatch for @react.component with React.forwardRef. https://github.com/rescript-lang/rescript/pull/7845

:nail_care: Polish

• Improve error message for trying to define a type inside a function. https://github.com/rescript-lang/rescript/pull/7843

• Refactor CLI to use spawn for better signal handling in watch mode. https://github.com/rescript-lang/rescript/pull/7844

• Add a prepareRename command the LSP can use for faster renames. https://github.com/rescript-lang/rescript/pull/7847

12.0.0-beta.9

:boom: Breaking Change

• Extract ReScript runtime files from main rescript package to separate @rescript/runtime package. https://github.com/rescript-lang/rescript/pull/7796
• Remove @rescript/std (in favor of @rescript/runtime). https://github.com/rescript-lang/rescript/pull/7811

:rocket: New Feature

• Add support for ArrayBuffer and typed arrays to @unboxed. https://github.com/rescript-lang/rescript/pull/7788
• Experimental: Add let? syntax for unwrapping and propagating errors/none as early returns for option/result types. https://github.com/rescript-lang/rescript/pull/7582
• Add support for shipping features as experimental, including configuring what experimental features are enabled in rescript.json. https://github.com/rescript-lang/rescript/pull/7582

:bug: Bug fix

• Fix JS regex literal parsing in character classes. https://github.com/rescript-lang/rescript/pull/7790
• Fix creating interface for functions with upper bounded polymorphic args. https://github.com/rescript-lang/rescript/pull/7786

:nail_care: Polish

• Make parser less strict around leading attributes. https://github.com/rescript-lang/rescript/pull/7787
• Dedicated error message for ternary type mismatch. https://github.com/rescript-lang/rescript/pull/7804
• Dedicated error message for passing a braced ident to something expected to be a record. https://github.com/rescript-lang/rescript/pull/7806
• Hint about partial application when missing required argument in function call. https://github.com/rescript-lang/rescript/pull/7807
• More autocomplete improvements involving modules and module types. https://github.com/rescript-lang/rescript/pull/7795
• Autocomplete @react.componentWithProps attribute. https://github.com/rescript-lang/rescript/pull/7812
• Add some missing iframe attributes to domProps. https://github.com/rescript-lang/rescript/pull/7813
• Polish error message for inline record escaping scope. https://github.com/rescript-lang/rescript/pull/7808
• Formatter: Change placement of closing > in JSX. https://github.com/rescript-lang/rescript/pull/7803

:house: Internal

• Build runtime with rewatch on Windows, too. https://github.com/rescript-lang/rescript/pull/7794

12.0.0-beta.8

Do not use, npm package broken.

12.0.0-beta.7

:rocket: New Feature

• Add markdown divider between module doc and module type in hover information. https://github.com/rescript-lang/rescript/pull/7775
• Show docstrings before type expansions on hover. https://github.com/rescript-lang/rescript/pull/7774
• Autocomplete (and improved hovers) for first-class module unpacks. https://github.com/rescript-lang/rescript/pull/7780

:bug: Bug fix

• Fix semantic highlighting for array spreads, array access and dict literals. https://github.com/rescript-lang/rescript/pull/7789
• Preserve @as(...) decorator on record fields when creating interface. https://github.com/rescript-lang/rescript/pull/7779
• Fix parse error with nested record types and attributes on the field name that has the nested record type. https://github.com/rescript-lang/rescript/pull/7781
• Fix ppx resolution with package inside monorepo. https://github.com/rescript-lang/rescript/pull/7776
• Fix 'Unbound module type' errors that occurred when trying to async import modules. https://github.com/rescript-lang/rescript/pull/7783

:nail_care: Polish

• Allow skipping the leading pipe in variant definition with a leading constructor with an attribute. https://github.com/rescript-lang/rescript/pull/7782
• Better error message (and recovery) when using a keyword as a record field name. https://github.com/rescript-lang/rescript/pull/7784

12.0.0-beta.6

:boom: Breaking Change

• rescript format no longer accepts --all. All (non-dev) files of the current rescript.json are now formatted by default. https://github.com/rescript-lang/rescript/pull/7752

:rocket: New Feature

• Add new Stdlib helpers: String.capitalize, String.isEmpty, Dict.size, Dict.isEmpty, Array.isEmpty, Map.isEmpty, Set.isEmpty. https://github.com/rescript-lang/rescript/pull/7516

:bug: Bug fix

• Fix issue with ast conversion (for ppx use) on functions with attributes on first argument. https://github.com/rescript-lang/rescript/pull/7761

:nail_care: Polish

• rescript format now has a --dev flag that works similar to rescript clean. https://github.com/rescript-lang/rescript/pull/7752
• rescript clean now will clean an individual project (see #7707). https://github.com/rescript-lang/rescript/pull/7752
• rescript clean will log multiple in-source extensions if present. https://github.com/rescript-lang/rescript/pull/7769

:house: Internal

• AST: Use jsx_tag_name instead of Longindent.t to store jsx tag name. https://github.com/rescript-lang/rescript/pull/7760

12.0.0-beta.5

:bug: Bug fix

• Fix option optimisation that resulted in incorrect JS output. https://github.com/rescript-lang/rescript/pull/7766
• Fix formatting of nested records in .resi files. https://github.com/rescript-lang/rescript/pull/7741
• Don't format and don't check formatting of dependencies. https://github.com/rescript-lang/rescript/pull/7748
• Fix rescript-editor-analysis semanticTokens returning invalid JSON in certain cases. https://github.com/rescript-lang/rescript/pull/7750

:memo: Documentation

• Update jsx schema configuration. https://github.com/rescript-lang/rescript/pull/7755

:nail_care: Polish

• Read package name from rescript.json if package.json is absent. https://github.com/rescript-lang/rescript/pull/7746

:house: Internal

• Add token viewer to res_parser. https://github.com/rescript-lang/rescript/pull/7751
• Refactor jsx mode in Scanner. https://github.com/rescript-lang/rescript/pull/7751

12.0.0-beta.4

:bug: Bug fix

• Fix error message that falsely suggested using coercion when it wouldn't work. https://github.com/rescript-lang/rescript/pull/7721
• Fix hang in rescript-editor-analysis.exe codeAction that sometimes prevented ReScript files from being saved in VS Code. https://github.com/rescript-lang/rescript/pull/7731
• Fix formatter removing () from functor type. https://github.com/rescript-lang/rescript/pull/7735
• Rewatch: don't compile dev-dependencies of non local dependencies with --dev. https://github.com/rescript-lang/rescript/pull/7736

:nail_care: Polish

• Apply heuristic to suggest using JSX fragments where we guess that might be what the user wanted. https://github.com/rescript-lang/rescript/pull/7714
• Show deprecation warnings for bs-dependencies etc. for local dependencies only. https://github.com/rescript-lang/rescript/pull/7724
• Add check for minimum required node version. https://github.com/rescript-lang/rescript/pull/7723
• Use more optional args in stdlib and deprecate some functions. https://github.com/rescript-lang/rescript/pull/7730
• Improve error message for when trying to do dot access on an option/array. https://github.com/rescript-lang/rescript/pull/7732

12.0.0-beta.3

:boom: Breaking Change

• Result.getOrThrow now throws a JS error instead of a Not_found ReScript exception. https://github.com/rescript-lang/rescript/pull/7630
• Remove rescript dump command. bsc can be used directly to dump the contents of a .cmi file instead if needed. https://github.com/rescript-lang/rescript/pull/7710

:rocket: New Feature

• Add optional message argument to Result.getOrThrow and improve default error message. https://github.com/rescript-lang/rescript/pull/7630
• Add RegExp.escape binding. https://github.com/rescript-lang/rescript/pull/7695

:bug: Bug fix

• Fix --create-sourcedirs generation with for a single project. https://github.com/rescript-lang/rescript/pull/7671
• Fix rewatch not recompiling on changes on Windows. https://github.com/rescript-lang/rescript/pull/7690
• Fix locations of regex literals. https://github.com/rescript-lang/rescript/pull/7683
• Fix async React component compilation. https://github.com/rescript-lang/rescript/pull/7704
• Fix @this with async keyword. https://github.com/rescript-lang/rescript/pull/7702

:nail_care: Polish

• Configuration fields bs-dependencies, bs-dev-dependencies and bsc-flags are now deprecated in favor of dependencies, dev-dependencies and compiler-flags. https://github.com/rescript-lang/rescript/pull/7658
• Better error message if platform binaries package is not found. https://github.com/rescript-lang/rescript/pull/7698
• Hint in error for string constants matching expected variant/polyvariant constructor. https://github.com/rescript-lang/rescript/pull/7711
• Polish arity mismatch error message a bit. https://github.com/rescript-lang/rescript/pull/7709
• Suggest related functions with the expected arity in errors when it makes sense. https://github.com/rescript-lang/rescript/pull/7712
• Improve error when a constructor expects an inline record. https://github.com/rescript-lang/rescript/pull/7713
• Remove @meth attribute. https://github.com/rescript-lang/rescript/pull/7684

:house: Internal

• Add rust linting to CI with clippy. https://github.com/rescript-lang/rescript/pull/7675
• AST: use Typ.arrows for creation, after the refactoring of arrow types. https://github.com/rescript-lang/rescript/pull/7662
• Don't skip Stdlib docstring tests. https://github.com/rescript-lang/rescript/pull/7694
• Remove all leftovers of pinned-dependencies handling. https://github.com/rescript-lang/rescript/pull/7686
• Add rust-version field to Rewatch's Cargo.toml. https://github.com/rescript-lang/rescript/pull/7701
• Rewatch: remove support for .ml(i) and .re(i). https://github.com/rescript-lang/rescript/pull/7727

12.0.0-beta.2

:boom: Breaking Change

• Rust implementation of the rescript format command. Command line options changed from -all, -check and -stdin to --all, --check and --stdin compared to the legacy implementation. https://github.com/rescript-lang/rescript/pull/7603

:rocket: New Feature

• Add experimental command to rescript-tools for extracting all ReScript code blocks from markdown, either a md-file directly, or inside of docstrings in ReScript code. https://github.com/rescript-lang/rescript/pull/7623

:bug: Bug fix

• Fix typeof parens on functions. https://github.com/rescript-lang/rescript/pull/7643
• Rewatch: Add --dev flag to clean command. https://github.com/rescript-lang/rescript/pull/7622
• Rewatch: Use root package suffix in clean log messages. https://github.com/rescript-lang/rescript/pull/7648
• Fix inside comment printing for empty dict. https://github.com/rescript-lang/rescript/pull/7654
• Fix I/O error message when trying to extract extra info from non-existing file. https://github.com/rescript-lang/rescript/pull/7656
• Fix fatal error when JSX expression used without configuring JSX in rescript.json. https://github.com/rescript-lang/rescript/pull/7656
• Rewatch: Only allow access to "bs-dev-dependencies" from "type": "dev" source files. https://github.com/rescript-lang/rescript/pull/7650
• Fix comment attached to array element. https://github.com/rescript-lang/rescript/pull/7672
• Rewatch: fix compilation of files starting with a lowercase letter. https://github.com/rescript-lang/rescript/pull/7700

:nail_care: Polish

• Add missing backtick and spaces to Belt.Map.map doc comment. https://github.com/rescript-lang/rescript/pull/7632
• AST: store the attributes directly on function arguments. https://github.com/rescript-lang/rescript/pull/7660

:house: Internal

• Remove internal/unused -bs-v flag. https://github.com/rescript-lang/rescript/pull/7627
• Remove unused -bs-D and -bs-list-conditionals flags. https://github.com/rescript-lang/rescript/pull/7631
• Remove obsolete jsx options. https://github.com/rescript-lang/rescript/pull/7633
• Remove obsolete option -bs-unsafe-empty-array. https://github.com/rescript-lang/rescript/pull/7635
• Clean up config.ml. https://github.com/rescript-lang/rescript/pull/7636
• Rewatch: simplify getting bsc path. https://github.com/rescript-lang/rescript/pull/7634
• Rewatch: only get "type": "dev" source files for local packages. https://github.com/rescript-lang/rescript/pull/7646
• Rewatch: add support for rescript -w for compatibility. https://github.com/rescript-lang/rescript/pull/7649
• Fix dev container. https://github.com/rescript-lang/rescript/pull/7700

12.0.0-beta.1

:rocket: New Feature

• Add experimental command to rescript-tools for formatting all ReScript code blocks in markdown. Either in a markdown file directly, or inside of docstrings in ReScript code. https://github.com/rescript-lang/rescript/pull/7598
• Add String.getSymbolUnsafe back to Stdlib. https://github.com/rescript-lang/rescript/pull/7626

:nail_care: Polish

• Add a warning if the name in package.json does not match the name in rescript.json. https://github.com/rescript-lang/rescript/pull/7604

:house: Internal

• Remove uncurried handling from rewatch. https://github.com/rescript-lang/rescript/pull/7625

12.0.0-alpha.15

:boom: Breaking Change

• New rewatch based build system. https://github.com/rescript-lang/rescript/pull/7551 https://github.com/rescript-lang/rescript/pull/7593
  • The new rewatch based build system is now the default and is exposed through the rescript command. The rewatch command has been removed.
  • The previous Ninja-based build system is now available via the rescript legacy subcommand.
  • Argument --compiler-args is now a subcommand compiler-args.
• Remove String.getSymbol, String.getSymbolUnsafe, String.setSymbol from standard library. https://github.com/rescript-lang/rescript/pull/7571

:bug: Bug fix

• Ignore inferred arity in functions inside %raw functions, leaving to %ffi the responsibility to check the arity since it gives an error in case of mismatch. https://github.com/rescript-lang/rescript/pull/7542
• Pass the rewatch exit code through in wrapper script. https://github.com/rescript-lang/rescript/pull/7565
• Prop punning when types don't match results in I/O error: _none_: No such file or directory. https://github.com/rescript-lang/rescript/pull/7533
• Pass location to children prop in jsx ppx. https://github.com/rescript-lang/rescript/pull/7540
• Fix crash when -bs-g is used with untagged variants. https://github.com/rescript-lang/rescript/pull/7575
• Fix issue with preserve mode where jsx is declared as an external without a @module attribute. https://github.com/rescript-lang/rescript/pull/7591
• Rewatch: don't add deps to modules that are in packages that are not a dependency. https://github.com/rescript-lang/rescript/pull/7612
• Rewatch: fix non-unicode stderr. https://github.com/rescript-lang/rescript/pull/7613
• Fix rewatch considering warning configs of non-local dependencies. https://github.com/rescript-lang/rescript/pull/7614
• Rewatch: fix panic if package.json name different from module name. https://github.com/rescript-lang/rescript/pull/7616
• Fix finding the standard library for pnpm. https://github.com/rescript-lang/rescript/pull/7615

:nail_care: Polish

• Better error message for when trying to await something that is not a promise. https://github.com/rescript-lang/rescript/pull/7561
• Better error messages for object field missing and object field type mismatches. https://github.com/rescript-lang/rescript/pull/7580
• Better error messages for when polymorphic variants does not match for various reasons. https://github.com/rescript-lang/rescript/pull/7596
• Improved completions for inline records. https://github.com/rescript-lang/rescript/pull/7601
• Add OrThrow aliases for Belt functions ending with Exn. https://github.com/rescript-lang/rescript/pull/7581, https://github.com/rescript-lang/rescript/pull/7590 The following aliases have been added:
  • Belt.Array.getOrThrow
  • Belt.Array.setOrThrow
  • Belt.Map.getOrThrow
  • Belt.MutableMap.getOrThrow
  • Belt.Set.getOrThrow
  • Belt.MutableSet.getOrThrow
  • Belt.List.getOrThrow
  • Belt.List.tailOrThrow
  • Belt.List.headOrThrow
  • Belt.MutableQueue.peekOrThrow
  • Belt.MutableQueue.popOrThrow
  • Belt.Option.getOrThrow
  • Belt.Result.getOrThrow

:house: Internal

• Remove @return(undefined_to_opt) and %undefined_to_opt primitive. https://github.com/rescript-lang/rescript/pull/7462
• Migrate rewatch to Rust 2024 edition. https://github.com/rescript-lang/rescript/pull/7602

12.0.0-alpha.14

:boom: Breaking Change

• Iterator.forEach now emits Iterator.prototype.forEach call. https://github.com/rescript-lang/rescript/pull/7506
• Rename functions ending with Exn to end with OrThrow. The old Exn functions are now deprecated:
  • Bool.fromStringExn → Bool.fromStringOrThrow
  • BigInt.fromStringExn → BigInt.fromStringOrThrow
  • JSON.parseExn → JSON.parseOrThrow
  • Changed BigInt.fromFloat to return an option rather than throwing an error.
  • Added BigInt.fromFloatOrThrow
  • Option.getExn → Option.getOrThrow
  • Null.getExn → Null.getOrThrow
  • Nullable.getExn → Nullable.getOrThrow
  • Result.getExn → Result.getOrThrow
  • List.getExn → List.getOrThrow
  • List.tailExn → List.tailOrThrow
  • List.headExn → List.headOrThrow
  • Old functions remain available but are marked as deprecated with guidance to use the new OrThrow variants.
  • https://github.com/rescript-lang/rescript/pull/7518, https://github.com/rescript-lang/rescript/pull/7554

:rocket: New Feature

• Add RegExp.flags. https://github.com/rescript-lang/rescript/pull/7461
• Add Array.findLast, Array.findLastWithIndex, Array.findLastIndex, Array.findLastIndexWithIndex and Array.findLastIndexOpt. https://github.com/rescript-lang/rescript/pull/7503
• Add options argument to Console.dir. https://github.com/rescript-lang/rescript/pull/7504
• Show variant constructor's inline record types on hover. https://github.com/rescript-lang/rescript/pull/7519
• Add additional Iterator.prototype bindings to runtime/Stdlib_Iterator.res. https://github.com/rescript-lang/rescript/pull/7506

:bug: Bug fix

• rescript-tools doc no longer includes shadowed bindings in its output. https://github.com/rescript-lang/rescript/pull/7497
• Treat throw like raise in analysis. https://github.com/rescript-lang/rescript/pull/7521
• Fix index out of bounds exception thrown in rare cases by rescript-editor-analysis.exe codeAction command. https://github.com/rescript-lang/rescript/pull/7523
• Don't produce duplicate type definitions for recursive types on hover. https://github.com/rescript-lang/rescript/pull/7524
• Prop punning when types don't match results in I/O error: _none_: No such file or directory. https://github.com/rescript-lang/rescript/pull/7533
• Fix partial application with user-defined function types. https://github.com/rescript-lang/rescript/pull/7548
• Fix doc comment before variant throwing syntax error. https://github.com/rescript-lang/rescript/pull/7535
• Fix apparent non-determinism in generated code for pattern matching. https://github.com/rescript-lang/rescript/pull/7557

:nail_care: Polish

• Suggest awaiting promise before using it when types mismatch. https://github.com/rescript-lang/rescript/pull/7498
• Complete from RegExp stdlib module for regexes. https://github.com/rescript-lang/rescript/pull/7425
• Allow oneliner formatting when including module with single type alias. https://github.com/rescript-lang/rescript/pull/7502
• Improve error messages for JSX type mismatches, passing objects where record is expected, passing array literal where tuple is expected, and more. https://github.com/rescript-lang/rescript/pull/7500
• Show in error messages when coercion can be used to fix a type mismatch. https://github.com/rescript-lang/rescript/pull/7505
• Remove deprecated pipe last (|>) syntax. https://github.com/rescript-lang/rescript/pull/7512
• Improve error message for pipe (->) syntax. https://github.com/rescript-lang/rescript/pull/7520
• Improve a few error messages around various subtyping issues. https://github.com/rescript-lang/rescript/pull/7404
• In module declarations, accept the invalid syntax M = {...} and format it to M : {...}. https://github.com/rescript-lang/rescript/pull/7527
• Improve doc comment formatting to match the style of multiline comments. https://github.com/rescript-lang/rescript/pull/7529
• Improve error messages around type mismatches for try/catch, if, for, while, and optional record fields + optional function arguments. https://github.com/rescript-lang/rescript/pull/7522
• Sync reanalyze with the new APIs around exception. https://github.com/rescript-lang/rescript/pull/7536
• Improve array pattern spread error message. https://github.com/rescript-lang/rescript/pull/7549
• Sync API docs with rescript-lang.org on release. https://github.com/rescript-lang/rescript/pull/7555

:house: Internal

• Refactor the ast for record expressions and patterns. https://github.com/rescript-lang/rescript/pull/7528
• Editor: add completions from included modules. https://github.com/rescript-lang/rescript/pull/7515
• Add -editor-mode arg to bsc for doing special optimizations only relevant to the editor tooling. https://github.com/rescript-lang/rescript/pull/7541

12.0.0-alpha.13

:boom: Breaking Change

• Rename JsError to JsExn and error modules cleanup. https://github.com/rescript-lang/rescript/pull/7408
• Make BigInt.fromFloat return an option rather than throwing an error in case it's passed a value with a decimal value. https://github.com/rescript-lang/rescript/pull/7419

:rocket: New Feature

• Add shift (<<, >>, >>>) operators for int and bigint. https://github.com/rescript-lang/rescript/pull/7183
• Add bitwise AND (&) operator for int and bigint. https://github.com/rescript-lang/rescript/pull/7415
• Add bitwise NOT (~) operator for int and bigint. https://github.com/rescript-lang/rescript/pull/7418
• Significantly reduced the download size by splitting binaries into optional platform-specific dependencies (e.g, @rescript/linux-x64). https://github.com/rescript-lang/rescript/pull/7395
• JSX: do not error on ref as prop anymore (which is allowed in React 19). https://github.com/rescript-lang/rescript/pull/7420
• Add new attribute @notUndefined for abstract types to prevent unnecessary wrapping with Primitive_option.some in JS output. https://github.com/rescript-lang/rescript/pull/7458
• Preserve JSX: enable by adding "-bs-jsx-preserve" to "bsc-flags" (does require "jsx": { "version": 4 }). https://github.com/rescript-lang/rescript/pull/7387
• Add slot prop to JsxDOM.domProps. https://github.com/rescript-lang/rescript/pull/7487

:bug: Bug fix

• Fix broken bstracing CLI location. https://github.com/rescript-lang/rescript/pull/7398
• Fix field flattening optimization to avoid creating unnecessary copies of allocating constants. https://github.com/rescript-lang/rescript-compiler/pull/7421
• Fix leading comments removed when braces inside JSX contains let assignment. https://github.com/rescript-lang/rescript/pull/7424
• Fix JSON escaping in code editor analysis: JSON was not always escaped properly, which prevented code actions from being available in certain situations. https://github.com/rescript-lang/rescript/pull/7435
• Fix regression in pattern matching for optional fields containing variants. https://github.com/rescript-lang/rescript/pull/7440
• Fix missing checks for duplicate literals in variants with payloads. https://github.com/rescript-lang/rescript/pull/7441
• Fix printer removing private for empty record. https://github.com/rescript-lang/rescript/pull/7448
• Fix: handle dynamic imports with module aliases. https://github.com/rescript-lang/rescript/pull/7452
• Fix missing unescaping when accessing prop with exotic name. https://github.com/rescript-lang/rescript/pull/7469
• Fix syntax error with mutable nested record. https://github.com/rescript-lang/rescript/pull/7470

:house: Internal

• AST: Add bar location to case. https://github.com/rescript-lang/rescript/pull/7407
• Clean up lazy from ASTs and back-end. https://github.com/rescript-lang/rescript/pull/7474
• Compile runtime with rewatch and add rewatch tests to the compiler repo. https://github.com/rescript-lang/rescript/pull/7422

:nail_care: Polish

• In type errors, recommend stdlib over Belt functions for converting between float/int/string. https://github.com/rescript-lang/rescript/pull/7453
• Remove unused type Jsx.ref. https://github.com/rescript-lang/rescript/pull/7459
• Add @notUndefined attribute to all relevant abstract types in Stdlib. https://github.com/rescript-lang/rescript/pull/7464
• Editor: Add pipe completions from current module. https://github.com/rescript-lang/rescript/pull/7471

12.0.0-alpha.12

:bug: Bug fix

• Fix node.js ExperimentalWarning. https://github.com/rescript-lang/rescript/pull/7379
• Fix issue with gentype and stdlib json. https://github.com/rescript-lang/rescript/pull/7378
• Fix type of RegExp.Result.matches. https://github.com/rescript-lang/rescript/pull/7393
• Add optional flags argument to RegExp.fromString and deprecate RegExp.fromStringWithFlags. https://github.com/rescript-lang/rescript/pull/7393

:house: Internal

• Better representation of JSX in AST. https://github.com/rescript-lang/rescript/pull/7286
• Clean up default warnings. https://github.com/rescript-lang/rescript/pull/7413

:nail_care: Polish

• Improve error message for missing value when the identifier is also the name of a module in scope. https://github.com/rescript-lang/rescript/pull/7384
• Upgrade Flow parser to 0.267.0. https://github.com/rescript-lang/rescript/pull/7390
• Move Lazy module to Stdlib. https://github.com/rescript-lang/rescript/pull/7399

12.0.0-alpha.11

:bug: Bug fix

• Fix Error.fromException. https://github.com/rescript-lang/rescript/pull/7364
• Fix signature of throw. https://github.com/rescript-lang/rescript/pull/7365
• Fix formatter adds superfluous parens in pipe chain. https://github.com/rescript-lang/rescript/pull/7370

:house: Internal

• Remove Stdlib_Char module for now. https://github.com/rescript-lang/rescript/pull/7367
• Convert internal JavaScript codebase into ESM, ReScript package itself is now ESM ("type": "module"). https://github.com/rescript-lang/rescript/pull/6899
• Add built-in support for the JavaScript in operator. https://github.com/rescript-lang/rescript/pull/7342
• AST cleanup: add Pexp_await ast node instead of res.await attribute. (The attribute is still used for await on modules currently). https://github.com/rescript-lang/rescript/pull/7368

:nail_care: Polish

• More deprecations in Pervasives; add Stdlib.Pair and Stdlib.Int.Ref. https://github.com/rescript-lang/rescript/pull/7371

12.0.0-alpha.10

:rocket: New Feature

• Add Dict.has and double Dict.forEachWithKey/Dict.mapValues performance. https://github.com/rescript-lang/rescript/pull/7316
• Add popover attributes to JsxDOM.domProps. https://github.com/rescript-lang/rescript/pull/7317
• Add Array.removeInPlace helper based on splice. https://github.com/rescript-lang/rescript/pull/7321
• Add inert attribute to JsxDOM.domProps. https://github.com/rescript-lang/rescript/pull/7326
• Make reanalyze exception tracking work with the new stdlib. https://github.com/rescript-lang/rescript/pull/7328
• Fix Pervasive.max using boolean comparison for floats. https://github.com/rescript-lang/rescript/pull/7333
• Experimental: Support nested/inline record types - records defined inside of other records, without needing explicit separate type definitions. https://github.com/rescript-lang/rescript/pull/7241
• Add unified exponentiation (**) operator for numeric types using ES7 **. https://github.com/rescript-lang/rescript-compiler/pull/7153
• Rename raise to throw to align with JavaScript vocabulary. raise has been deprecated. https://github.com/rescript-lang/rescript/pull/7346
• Add unified bitwise (^) operator. https://github.com/rescript-lang/rescript/pull/7216
• Stdlib: rename binary operations to match JavaScript terms. https://github.com/rescript-lang/rescript/pull/7353

:boom: Breaking Change

• Replace ~date with ~day in Date.make. https://github.com/rescript-lang/rescript/pull/7324
• Remove -bs-jsx-mode. https://github.com/rescript-lang/rescript/pull/7327
• Drop Node.js version <20 support, as it is reaching End-of-Life. https://github.com/rescript-lang/rescript-compiler/pull/7354
• Treat int multiplication as a normal int32 operation instead of using Math.imul. https://github.com/rescript-lang/rescript/pull/7358

:house: Internal

• Clean up legacy tags handling. https://github.com/rescript-lang/rescript/pull/7309
• Use Yarn (Berry) workspaces for internal tooling. https://github.com/rescript-lang/rescript/pull/7309

:nail_care: Polish

• Deprecate JSON.Classify.classify. https://github.com/rescript-lang/rescript/pull/7315
• Hide stdlib modules in output. https://github.com/rescript-lang/rescript/pull/7305
• Deprecate unsafe host-specific bindings from stdlib. https://github.com/rescript-lang/rescript/pull/7334
• Make unsafe function names consistent in Stdlib.String. https://github.com/rescript-lang/rescript/pull/7337
• rescript package does not trigger postinstall script anymore. https://github.com/rescript-lang/rescript/pull/7350
• Add Stdlib Bool and Char modules and improve Pervasives deprecation messages. https://github.com/rescript-lang/rescript/pull/7361

:bug: Bug fix

• Fix recursive untagged variant type checking by delaying well-formedness checks until environment construction completes. https://github.com/rescript-lang/rescript/pull/7320
• Fix incorrect expansion of polymorphic return types in uncurried function applications. https://github.com/rescript-lang/rescript/pull/7338

12.0.0-alpha.9

:boom: Breaking Change

• Clean list API. https://github.com/rescript-lang/rescript/pull/7290

:nail_care: Polish

• Allow single newline in JSX. https://github.com/rescript-lang/rescript/pull/7269
• Editor: Always complete from Core first. Use actual native regex syntax in code snippets for regexps. https://github.com/rescript-lang/rescript/pull/7295
• Add type t to Stdlib modules. https://github.com/rescript-lang/rescript/pull/7302
• Gentype: handle null/nullable/undefined from Stdlib. https://github.com/rescript-lang/rescript/pull/7132

:bug: Bug fix

• Fix async context checking for module await. https://github.com/rescript-lang/rescript/pull/7271
• Fix %external extension. https://github.com/rescript-lang/rescript/pull/7272
• Fix issue with type environment for unified ops. https://github.com/rescript-lang/rescript/pull/7277
• Fix completion for application with tagged template. https://github.com/rescript-lang/rescript/pull/7278
• Fix error message for arity in the presence of optional arguments. https://github.com/rescript-lang/rescript/pull/7284
• Fix issue in functors with more than one argument (which are curried): emit nested function always. https://github.com/rescript-lang/rescript/pull/7273
• Fix dot completion issue with React primitives. https://github.com/rescript-lang/rescript/pull/7292
• Stdlib namespace for Core modules (fixes name clashes with user modules). https://github.com/rescript-lang/rescript/pull/7285
• Fix runtime type check for Object in untagged variants when one variant case is null. https://github.com/rescript-lang/rescript/pull/7303
• Fix files that were being truncated when sent to the CDN over FTP. https://github.com/rescript-lang/rescript/pull/7306
• Fix better editor completion for applications. https://github.com/rescript-lang/rescript/pull/7291
• Fix @react.componentWithProps no longer works with @directive("'use memo'"). https://github.com/rescript-lang/rescript/pull/7300

:house: Internal

• Remove ignore in res_scanner.ml. https://github.com/rescript-lang/rescript/pull/7280
• Use the new stdlib modules in the analysis tests. https://github.com/rescript-lang/rescript/pull/7295
• Build with OCaml 5.3.0. https://github.com/rescript-lang/rescript/pull/7294
• Simplify JSON.Decode implementation. https://github.com/rescript-lang/rescript/pull/7304

12.0.0-alpha.8

:bug: Bug fix

• Editor: Fix issue where pipe completions would not trigger with generic type arguments. https://github.com/rescript-lang/rescript/pull/7231
• Fix leftover assert false in code for null != undefined. https://github.com/rescript-lang/rescript/pull/7232
• Editor: Fix issue where completions would not show up inside of object bodies. https://github.com/rescript-lang/rescript/pull/7230
• Fix issue with pattern matching empty list which interferes with boolean optimisations. https://github.com/rescript-lang/rescript/pull/7237
• Fix Cannot combine @react.component and @directive. https://github.com/rescript-lang/rescript/pull/7260
• Fix issue where attributes on an application were not preserved by the AST conversion for ppx. https://github.com/rescript-lang/rescript/pull/7262

:house: Internal

• AST cleanup: Prepare for ast async cleanup: Refactor code for @res.async payload handling and clean up handling of type and term parameters, so that now each => in a function definition corresponds to a function. https://github.com/rescript-lang/rescript/pull/7223
• AST: always put type parameters first in function definitions. https://github.com/rescript-lang/rescript/pull/7233
• AST cleanup: Remove @res.async attribute from the internal representation, and add a flag to untyped and typed ASTs instead. https://github.com/rescript-lang/rescript/pull/7234
• AST cleanup: Remove unused expression_desc.Pexp_new, expression_desc.Pexp_setinstvar, expression_desc.Pexp_override, expression_desc.Pexp_poly, exp_extra.Texp_poly, expression_desc.Texp_new, expression_desc.Texp_setinstvar, expression_desc.Texp_override & expression_desc.Texp_instvar from AST. https://github.com/rescript-lang/rescript/pull/7239
• AST cleanup: Remove @res.partial attribute from the internal representation, and add a flag to untyped and typed ASTs instead. https://github.com/rescript-lang/rescript/pull/7238 https://github.com/rescript-lang/rescript/pull/7240
• AST cleanup: Remove unused structure_item_desc.Pstr_class, signature_item_desc.Psig_class, structure_item_desc.Pstr_class_type, signature_item_desc.Psig_class_type, structure_item_desc.Tstr_class, structure_item_desc.Tstr_class_type, signature_item_desc.Tsig_class, signature_item_desc.Tsig_class_type from AST. https://github.com/rescript-lang/rescript/pull/7242
• AST cleanup: remove |. and rename |. to -> in the internal representation for the pipe operator. https://github.com/rescript-lang/rescript/pull/7244
• AST cleanup: represent concatenation (++) and (dis)equality operators (==, ===, !=, !==) just like in the syntax. https://github.com/rescript-lang/rescript/pull/7248
• AST cleanup: use inline record for Ptyp_arrow. https://github.com/rescript-lang/rescript/pull/7250
• Playground: Bundle stdlib runtime so that the playground can execute functions from Core/Belt/Js. https://github.com/rescript-lang/rescript/pull/7255
• AST cleanup: Remove res.namedArgLoc attribute and store the location information directly into the label. https://github.com/rescript-lang/rescript/pull/7247

:nail_care: Polish

• Rewatch 1.0.10. https://github.com/rescript-lang/rescript/pull/7259

12.0.0-alpha.7

:bug: Bug fix

• Editor: Fix issue where completions would stop working in some scenarios with inline records. https://github.com/rescript-lang/rescript/pull/7227

:nail_care: Polish

• Add all standard CSS properties to JsxDOMStyle. https://github.com/rescript-lang/rescript/pull/7205

:house: Internal

• AST cleanup: use inline record for Pexp_fun. https://github.com/rescript-lang/rescript/pull/7213
• Add support for "dot completion everywhere" (ported from https://github.com/rescript-lang/rescript-vscode/pull/1054). https://github.com/rescript-lang/rescript/pull/7226
• Add assertions to stdlib docstring examples. Extract examples into Mocha tests, compile and run the tests in CI. https://github.com/rescript-lang/rescript/pull/7219

12.0.0-alpha.6

:rocket: New Feature

• Add Option.all & Result.all helpers. https://github.com/rescript-lang/rescript/pull/7181
• Add @react.componentWithProps for React component functions taking a props record instead of labeled arguments. https://github.com/rescript-lang/rescript/pull/7203

:bug: Bug fix

• Fix exponential notation syntax. https://github.com/rescript-lang/rescript/pull/7174
• Fix bug where a ref assignment is moved ouside a conditional. https://github.com/rescript-lang/rescript/pull/7176
• Fix nullable to opt conversion. https://github.com/rescript-lang/rescript/pull/7193
• Raise error when defining external React components with @react.componentWithProps. https://github.com/rescript-lang/rescript/pull/7217
• Fix formatter handling of wildcard in pattern matching records with no fields specified. https://github.com/rescript-lang/rescript/pull/7224

:house: Internal

• Use latest compiler for tests. https://github.com/rescript-lang/rescript/pull/7186
• Added infra to modernise AST: theres' Parsetree, Parsetree0 (legacy), and conversion functions to keep compatibility with PPX. https://github.com/rescript-lang/rescript/pull/7185
• AST cleanup: remove exp object and exp unreachable. https://github.com/rescript-lang/rescript/pull/7189
• AST cleanup: explicit representation for optional record fields in types. https://github.com/rescript-lang/rescript/pull/7190 https://github.com/rescript-lang/rescript/pull/7191
• AST cleanup: first-class expression and patterns for records with optional fields. https://github.com/rescript-lang/rescript/pull/7192
• AST cleanup: Represent the arity of uncurried function definitions directly in the AST. https://github.com/rescript-lang/rescript/pull/7197
• AST cleanup: Remove Pexp_function from the AST. https://github.com/rescript-lang/rescript/pull/7198
• Remove unused code from Location and Rescript_cpp modules. https://github.com/rescript-lang/rescript/pull/7150
• Build with OCaml 5.2.1. https://github.com/rescript-lang/rescript-compiler/pull/7201
• AST cleanup: Remove Function$ entirely for function definitions. https://github.com/rescript-lang/rescript/pull/7200
• AST cleanup: store arity in function type. https://github.com/rescript-lang/rescript/pull/7195
• AST cleanup: remove explicit uses of function$ in preparation for removing the type entirely. https://github.com/rescript-lang/rescript/pull/7206
• AST cleanup: remove function$ entirely. https://github.com/rescript-lang/rescript/pull/7208

12.0.0-alpha.5

:rocket: New Feature

• Introduce "Unified operators" for arithmetic operators (+, -, *, /, mod). https://github.com/rescript-lang/rescript-compiler/pull/7057
• Add remainder (%, aka modulus) operator. https://github.com/rescript-lang/rescript-compiler/pull/7152

:bug: Bug fix

• Fix and clean up boolean and/or optimizations. https://github.com/rescript-lang/rescript-compiler/pull/7134 https://github.com/rescript-lang/rescript-compiler/pull/7151
• Fix identifiers with name arguments and eval to be mangled. https://github.com/rescript-lang/rescript/pull/7163

:nail_care: Polish

• Improve code generation for pattern matching of untagged variants. https://github.com/rescript-lang/rescript-compiler/pull/7128
• Improve negation handling in combination with and/or to simplify generated code (especially coming out of pattern matching). https://github.com/rescript-lang/rescript-compiler/pull/7138
• Optimize JavaScript code generation by using x == null checks and improving type-based optimizations for string/number literals. https://github.com/rescript-lang/rescript-compiler/pull/7141
• Improve pattern matching on optional fields. https://github.com/rescript-lang/rescript-compiler/pull/7143 https://github.com/rescript-lang/rescript-compiler/pull/7144
• Optimize compilation of switch statements for untagged variants when there are no literal cases. https://github.com/rescript-lang/rescript-compiler/pull/7135
• Further improve boolean optimizations. https://github.com/rescript-lang/rescript-compiler/pull/7149
• Simplify code generated for conditionals. https://github.com/rescript-lang/rescript-compiler/pull/7151

:house: Internal

• Move rescript-editor-analysis and rescript-tools into compiler repo. https://github.com/rescript-lang/rescript-compiler/pull/7000

12.0.0-alpha.4

:boom: Breaking Change

• OCaml compatibility in the stdlib and primitives are dropped/deprecated. https://github.com/rescript-lang/rescript-compiler/pull/6984
• Remove JSX v3. https://github.com/rescript-lang/rescript-compiler/pull/7072
• Remove js_cast.res. https://github.com/rescript-lang/rescript-compiler/pull/7075

:rocket: New Feature

• Use FORCE_COLOR environmental variable to force colorized output. https://github.com/rescript-lang/rescript-compiler/pull/7033
• Allow spreads of variants in patterns (| ...someVariant as v => ) when the variant spread is a subtype of the variant matched on. https://github.com/rescript-lang/rescript-compiler/pull/6721
• Fix the issue where dynamic imports are not working for function-defined externals. https://github.com/rescript-lang/rescript-compiler/pull/7060
• Allow pattern matching on dicts. switch someDict { | dict{"one": 1} => Js.log("one is one") }. https://github.com/rescript-lang/rescript-compiler/pull/7059
• "ReScript Core" standard library is now included in the rescript npm package. https://github.com/rescript-lang/rescript-compiler/pull/7108 https://github.com/rescript-lang/rescript-compiler/pull/7116
• Handle absolute filepaths in gentype. https://github.com/rescript-lang/rescript-compiler/pull/7104

:bug: Bug fix

• Fix tuple coercion. https://github.com/rescript-lang/rescript-compiler/pull/7024
• Fix attribute printing. https://github.com/rescript-lang/rescript-compiler/pull/7025
• Fix "rescript format" with many files. https://github.com/rescript-lang/rescript-compiler/pull/7081
• Fix bigint max, min. https://github.com/rescript-lang/rescript-compiler/pull/7088
• Fix parsing issue with nested variant pattern type spreads. https://github.com/rescript-lang/rescript-compiler/pull/7080
• Fix JSX settings inheritance: only 'version' propagates to dependencies, preserving their 'mode' and 'module'. https://github.com/rescript-lang/rescript-compiler/pull/7094
• Fix variant cast to int. https://github.com/rescript-lang/rescript-compiler/pull/7058
• Fix comments formatted away in function without arguments. https://github.com/rescript-lang/rescript-compiler/pull/7095
• Fix genType JSX component compilation. https://github.com/rescript-lang/rescript-compiler/pull/7107

:nail_care: Polish

• Add some context to error message for unused variables. https://github.com/rescript-lang/rescript-compiler/pull/7050
• Improve error message when passing children prop to a component that doesn't accept it. https://github.com/rescript-lang/rescript-compiler/pull/7044
• Improve error messages for pattern matching on option vs non-option, and vice versa. https://github.com/rescript-lang/rescript-compiler/pull/7035
• Improve bigint literal comparison. https://github.com/rescript-lang/rescript-compiler/pull/7029
• Improve output of @variadic bindings. https://github.com/rescript-lang/rescript-compiler/pull/7030
• Improve error messages around JSX components. https://github.com/rescript-lang/rescript-compiler/pull/7038
• Improve output of record copying. https://github.com/rescript-lang/rescript-compiler/pull/7043
• Provide additional context in error message when unit is expected. https://github.com/rescript-lang/rescript-compiler/pull/7045
• Improve error message when passing an object where a record is expected. https://github.com/rescript-lang/rescript-compiler/pull/7101

:house: Internal

• Remove uncurried flag from bsb. https://github.com/rescript-lang/rescript-compiler/pull/7049
• Build runtime/stdlib files with rescript/bsb instead of ninja.js. https://github.com/rescript-lang/rescript-compiler/pull/7063
• Build tests with bsb and move them out of jscomp. https://github.com/rescript-lang/rescript-compiler/pull/7068
• Run build_tests on Windows. https://github.com/rescript-lang/rescript-compiler/pull/7065
• Rename folder "jscomp" to "compiler". https://github.com/rescript-lang/rescript-compiler/pull/7086
• Disable -bs-cross-module-opt for tests. https://github.com/rescript-lang/rescript-compiler/pull/7071
• Move ounit_tests into the tests folder. https://github.com/rescript-lang/rescript-compiler/pull/7096
• Move syntax_tests into the tests folder. https://github.com/rescript-lang/rescript-compiler/pull/7090 https://github.com/rescript-lang/rescript-compiler/pull/7097
• Capitalize runtime filenames. https://github.com/rescript-lang/rescript-compiler/pull/7110
• Build mocha tests as esmodule / .mjs. https://github.com/rescript-lang/rescript-compiler/pull/7115
• Use dict instead of Dict.t everywhere. https://github.com/rescript-lang/rescript-compiler/pull/7136

12.0.0-alpha.3

:bug: Bug fix

• Revert "Throws an instance of JavaScript's new Error() and adds the extension payload for cause option" (https://github.com/rescript-lang/rescript-compiler/pull/6611). https://github.com/rescript-lang/rescript-compiler/pull/7016
• Fix dict literals error. https://github.com/rescript-lang/rescript-compiler/pull/7019

12.0.0-alpha.2

:rocket: New Feature

• Allow coercing polyvariants to variants when we can guarantee that the runtime representation matches. https://github.com/rescript-lang/rescript-compiler/pull/6981
• Add new dict literal syntax (dict{"foo": "bar"}). https://github.com/rescript-lang/rescript-compiler/pull/6774
• Optimize usage of the new dict literal syntax to emit an actual JS object literal. https://github.com/rescript-lang/rescript-compiler/pull/6538

:bug: Bug Fix

• Fix issue where long layout break added a trailing comma in partial application .... https://github.com/rescript-lang/rescript-compiler/pull/6949
• Fix incorrect format of function under unary operator. https://github.com/rescript-lang/rescript-compiler/pull/6953
• Fix incorrect printing of module binding with signature. https://github.com/rescript-lang/rescript-compiler/pull/6963
• Fix incorrect printing of external with @as attribute and _ placholder (fixed argument). https://github.com/rescript-lang/rescript-compiler/pull/6970
• Disallow spreading anything but regular variants inside of other variants. https://github.com/rescript-lang/rescript-compiler/pull/6980
• Fix comment removed when function signature has type keyword. https://github.com/rescript-lang/rescript-compiler/pull/6997
• Fix parse error on doc comment before "and" in type def. https://github.com/rescript-lang/rescript-compiler/pull/7001

:house: Internal

• Add dev container. https://github.com/rescript-lang/rescript-compiler/pull/6962
• Convert more tests to the node test runner. https://github.com/rescript-lang/rescript-compiler/pull/6956
• Remove attribute "internal.arity". https://github.com/rescript-lang/rescript-compiler/pull/7004
• Remove dead modules. https://github.com/rescript-lang/rescript-compiler/pull/7008

:nail_care: Polish

• Improve formatting in the generated js code. https://github.com/rescript-lang/rescript-compiler/pull/6932
  • }\ncatch{ -> } catch {
  • for(let i = 0 ,i_finish = r.length; i < i_finish; ++i){ -> for (let i = 0, i_finish = r.length; i < i_finish; ++i) {
  • while(true) { -> while (true) {
  • Fixed tabulation for switch case bodies
  • Fixed tabulation for throw new Error bodies
  • Removed empty line at the end of switch statement
  • Removed empty default case from switch statement in the generated code
• Optimised the Type Extension runtime code and removed trailing /1 from RE_EXN_ID. https://github.com/rescript-lang/rescript-compiler/pull/6958
• Compact output for anonymous functions. https://github.com/rescript-lang/rescript-compiler/pull/6945 https://github.com/rescript-lang/rescript-compiler/pull/7013
• Rewatch 1.0.9. https://github.com/rescript-lang/rescript-compiler/pull/7010

12.0.0-alpha.1

:rocket: New Feature

• Allow @directive on functions for emitting function level directive code (let serverAction = @directive("'use server'") (~name) => {...}). https://github.com/rescript-lang/rescript-compiler/pull/6756
• Add rewatch to the npm package as an alternative build tool. https://github.com/rescript-lang/rescript-compiler/pull/6762
• Throws an instance of JavaScript's new Error() and adds the extension payload for cause option. https://github.com/rescript-lang/rescript-compiler/pull/6611
• Allow free vars in types for type coercion e :> t. https://github.com/rescript-lang/rescript-compiler/pull/6828
• Allow private in with constraints. https://github.com/rescript-lang/rescript-compiler/pull/6843
• Add regex literals as syntax sugar for @bs.re. https://github.com/rescript-lang/rescript-compiler/pull/6776
• Improved mechanism to determine arity of externals, which is consistent however the type is written. https://github.com/rescript-lang/rescript-compiler/pull/6874 https://github.com/rescript-lang/rescript-compiler/pull/6881 https://github.com/rescript-lang/rescript-compiler/pull/6883
• Add Js.globalThis object binding. https://github.com/rescript-lang/rescript-compiler/pull/6909

:boom: Breaking Change

• Make j and js allowed names for tag functions. https://github.com/rescript-lang/rescript-compiler/pull/6817
• lazy syntax is no longer supported. If you're using it, use Lazy module or React.lazy_ instead. https://github.com/rescript-lang/rescript-compiler/pull/6342
• Remove handling of attributes with bs. prefix (@bs.as -> @as etc.). https://github.com/rescript-lang/rescript-compiler/pull/6643
• Remove obsolete @bs.open feature. https://github.com/rescript-lang/rescript-compiler/pull/6629
• Drop Node.js version <18 support, due to it reaching End-of-Life. https://github.com/rescript-lang/rescript-compiler/pull/6429
• Remove deprecated -bs-super-errors option. https://github.com/rescript-lang/rescript-compiler/pull/6814
• Some global names and old keywords are no longer prefixed. https://github.com/rescript-lang/rescript-compiler/pull/6831
• Remove ml parsing tests and conversion from .ml to .res via format. https://github.com/rescript-lang/rescript-compiler/pull/6848
• Remove support for compiling .ml files, and general cleanup. https://github.com/rescript-lang/rescript-compiler/pull/6852
• Remove rescript convert subcommand. https://github.com/rescript-lang/rescript-compiler/pull/6860
• Remove support for @bs.send.pipe. This also removes all functions in Js_typed_array that rely on @bs.send.pipe. https://github.com/rescript-lang/rescript-compiler/pull/6858 https://github.com/rescript-lang/rescript-compiler/pull/6891
• Remove deprecated Js.Vector and Js.List. https://github.com/rescript-lang/rescript-compiler/pull/6900
• Remove support for %time extension. https://github.com/rescript-lang/rescript-compiler/pull/6924
• Remove caml_external_polyfill module and the related behavior. https://github.com/rescript-lang/rescript-compiler/pull/6925

:bug: Bug Fix

• Fix unhandled cases for exotic idents (allow to use exotic PascalCased identifiers for types). https://github.com/rescript-lang/rescript-compiler/pull/6777 https://github.com/rescript-lang/rescript-compiler/pull/6779 https://github.com/rescript-lang/rescript-compiler/pull/6897
• Fix unused attribute check for @as. https://github.com/rescript-lang/rescript-compiler/pull/6795
• Reactivate unused attribute check for @int. https://github.com/rescript-lang/rescript-compiler/pull/6802
• Fix issue where using partial application ... can generate code that uses Curry at runtime. https://github.com/rescript-lang/rescript-compiler/pull/6872
• Avoid generation of Curry with reverse application |>. https://github.com/rescript-lang/rescript-compiler/pull/6876
• Fix issue where the internal ppx for pipe -> would not use uncurried application in uncurried mode. https://github.com/rescript-lang/rescript-compiler/pull/6878

:house: Internal

• Build with OCaml 5.2.0. https://github.com/rescript-lang/rescript-compiler/pull/6797
• Convert OCaml codebase to snake case style. https://github.com/rescript-lang/rescript-compiler/pull/6702
• Fix -nostdlib internal compiler option. https://github.com/rescript-lang/rescript-compiler/pull/6824
• Remove a number of ast nodes never populated by the .res parser, and resulting dead code. https://github.com/rescript-lang/rescript-compiler/pull/6830
• Remove coercion with 2 types from internal representation. Coercion e : t1 :> t2 was only supported in .ml syntax and never by the .res parser. https://github.com/rescript-lang/rescript-compiler/pull/6829
• Convert caml_format and js_math to .res. https://github.com/rescript-lang/rescript-compiler/pull/6834
• Convert js.ml files to .res. https://github.com/rescript-lang/rescript-compiler/pull/6835
• Remove old .ml tests. https://github.com/rescript-lang/rescript-compiler/pull/6847
• Make compiler libs ready for uncurried mode. https://github.com/rescript-lang/rescript-compiler/pull/6861
• Make tests ready for uncurried mode. https://github.com/rescript-lang/rescript-compiler/pull/6862
• Make gentype tests uncurried. https://github.com/rescript-lang/rescript-compiler/pull/6866
• Remove @@uncurried.swap, which was used for internal tests. https://github.com/rescript-lang/rescript-compiler/pull/6875
• Build the compiler libraries/tests in uncurried mode. https://github.com/rescript-lang/rescript-compiler/pull/6864
• Ignore -uncurried command-line flag. https://github.com/rescript-lang/rescript-compiler/pull/6885
• Cleanup: remove tracking of uncurried state in parser/printer. https://github.com/rescript-lang/rescript-compiler/pull/6888
• Remove %opaque primitive. https://github.com/rescript-lang/rescript-compiler/pull/6892
• Reunify JsxC/JsxU -> Jsx etc. https://github.com/rescript-lang/rescript-compiler/pull/6895
• Remove the transformation of foo(1,2) into Js.Internal.opaqueFullApply(Internal.opaque(f), 1, 2), and change the back-end to treat all applications as uncurried. https://github.com/rescript-lang/rescript-compiler/pull/6893
• Remove @uncurry from ReScript sources (others, tests). https://github.com/rescript-lang/rescript-compiler/pull/6938
• Remove leftover uncurried handling. https://github.com/rescript-lang/rescript-compiler/pull/6939 https://github.com/rescript-lang/rescript-compiler/pull/6940
• Start converting tests from mocha to the node test runner. https://github.com/rescript-lang/rescript-compiler/pull/6956

:nail_care: Polish

• Make the --help arg be prioritized in the CLI, so correctly prints help message and skip other commands. https://github.com/rescript-lang/rescript-compiler/pull/6667
• Remove redundant space for empty return in generated js code. https://github.com/rescript-lang/rescript-compiler/pull/6745
• Remove redundant space for export in generated js code. https://github.com/rescript-lang/rescript-compiler/pull/6560
• Remove redundant space after continue in generated js code. https://github.com/rescript-lang/rescript-compiler/pull/6743
• Remove empty export blocks in generated js code. https://github.com/rescript-lang/rescript-compiler/pull/6744
• Fix indent for returned/thrown/wrapped in parentheses objects in generated js code. https://github.com/rescript-lang/rescript-compiler/pull/6746
• Fix indent in generated js code. https://github.com/rescript-lang/rescript-compiler/pull/6747
• In generated code, use let instead of var. https://github.com/rescript-lang/rescript-compiler/pull/6102
• Turn off transformation for closures inside loops when capturing loop variables, now that let is emitted instead of var. https://github.com/rescript-lang/rescript-compiler/pull/6480
• Improve unused attribute warning message. https://github.com/rescript-lang/rescript-compiler/pull/6787
• Remove internal option use-stdlib from build schema. https://github.com/rescript-lang/rescript-compiler/pull/6778
• Fix Js.Types.JSBigInt payload to use native bigint type. https://github.com/rescript-lang/rescript-compiler/pull/6911
• Deprecate %external extension, which has never been officially introduced. https://github.com/rescript-lang/rescript-compiler/pull/6906
• Deprecate xxxU functions in Belt. https://github.com/rescript-lang/rescript-compiler/pull/6941
• Improve error messages for function arity errors. https://github.com/rescript-lang/rescript-compiler/pull/6990
• Add missing HTML attribute capture to JsxDOM.res. https://github.com/rescript-lang/rescript-compiler/pull/7006

11.1.3

:bug: Bug Fix

• Fix tag function location on compiler error. https://github.com/rescript-lang/rescript-compiler/pull/6816
• Fix Deno compatibility issues on Windows. https://github.com/rescript-lang/rescript-compiler/pull/6850
• Fix issue with infinite loops with type errors on recursive types. https://github.com/rescript-lang/rescript-compiler/pull/6867
• Ignore @uncurry attribute in uncurried mode, to avoid generating calls to Curry at runtime. https://github.com/rescript-lang/rescript-compiler/pull/6869
• Avoid generating calls to Curry when adjusting arity of uncurried functions. https://github.com/rescript-lang/rescript-compiler/pull/6870
• Fix build after calling without -warn-error, see https://github.com/rescript-lang/rescript-compiler/issues/6868 for more details. https://github.com/rescript-lang/rescript-compiler/pull/6877
• Fix issue with uninitialized _param in recursive functions with unit argument. https://github.com/rescript-lang/rescript-compiler/pull/6907

11.1.3-rc.1

:bug: Bug Fix

• Omit standard library dir from load path if -nostdlib is set. https://github.com/rescript-lang/rescript-compiler/pull/6833

11.1.2

:bug: Bug Fix

• Fix issue where capitalised type variables were only allowed in certain positions. https://github.com/rescript-lang/rescript-compiler/pull/6820

11.1.2-rc.1

:rocket: New Feature

• Support Windows 11 ARM (using the x64 binaries in emulation). https://github.com/rescript-lang/rescript-compiler/pull/6813

:bug: Bug Fix

• Fix location of let bindings with attributes. https://github.com/rescript-lang/rescript-compiler/pull/6791
• PPX v4: mark props type in externals as @live to avoid dead code warnings for prop fields in the editor tooling. https://github.com/rescript-lang/rescript-compiler/pull/6796
• Fix issue where optional labels were not taken into account when disambiguating record value construction. https://github.com/rescript-lang/rescript-compiler/pull/6798
• Fix issue in gentype when type Jsx.element surfaces to the user. https://github.com/rescript-lang/rescript-compiler/pull/6808
• Fix inclusion check (impl vs interface) for untagged variants, and fix the outcome printer to show tags. https://github.com/rescript-lang/rescript-compiler/pull/6669
• Fix encoding inside tagged template literals. https://github.com/rescript-lang/rescript-compiler/pull/6810

11.1.1

:bug: Bug Fix

• Fix issue of incorrect switch cases with identical bodies when mixing object and array. https://github.com/rescript-lang/rescript-compiler/pull/6792
• Fix formatter eats comments on the first argument of a uncurried function. https://github.com/rescript-lang/rescript-compiler/pull/6763
• Fix formatter removes parens in pipe operator with anonymous uncurried function. https://github.com/rescript-lang/rescript-compiler/pull/6766

11.1.0

:bug: Bug Fix

• Revert escape JSX prop names with hyphens (#6705). https://github.com/rescript-lang/rescript-compiler/pull/6731

11.1.0-rc.8

:rocket: New Feature

• Add %todo extension for leaving implementation for later. https://github.com/rescript-lang/rescript-compiler/pull/6713
• Add -warn-error argument for generating errors in CI. Useful for %todo extension. https://github.com/rescript-lang/rescript-compiler/pull/6717

:bug: Bug Fix

• Improve error when using @deriving(accessors) on a variant with record arguments. https://github.com/rescript-lang/rescript-compiler/pull/6712
• Stop escaping JSX prop names with hyphens. https://github.com/rescript-lang/rescript-compiler/pull/6705
• Fix trailing undefined for optional parameters not omitted with @send and @new. https://github.com/rescript-lang/rescript-compiler/pull/6716
• Fix JSX4 adding the incorrect type annotation for the prop ref in React.forwardRef component. https://github.com/rescript-lang/rescript-compiler/pull/6718
• Fix description for warning number 110. https://github.com/rescript-lang/rescript-compiler/pull/6725

:nail_care: Polish

• Module spec es6 and es6-global is deprecated in favor of esmodule. https://github.com/rescript-lang/rescript-compiler/pull/6709

11.1.0-rc.7

:bug: Bug Fix

• Fix variance setting for builtin dict type. Fixes issues around inference. https://github.com/rescript-lang/rescript-compiler/pull/6707

11.1.0-rc.6

:rocket: New Feature

• Add experimental BigInt support. https://github.com/rescript-lang/rescript-compiler/pull/6670, https://github.com/rescript-lang/rescript-compiler/pull/6696

:bug: Bug Fix

• Fix mishandling of uncurried functions in super errors. https://github.com/rescript-lang/rescript-compiler/pull/6694

11.1.0-rc.5

:bug: Bug Fix

• Fix misparsing in/after JSX. https://github.com/rescript-lang/rescript-compiler/pull/6686
• Fix @deriving(accessors) outputting curried functions in uncurried mode. https://github.com/rescript-lang/rescript-compiler/pull/6687

11.1.0-rc.4

:bug: Bug Fix

• Fix emitting static import instead of dynamic import. https://github.com/rescript-lang/rescript-compiler/pull/6664
• Fix local type variables breaking react components. https://github.com/rescript-lang/rescript-compiler/pull/6665
• Fix remove redundant branches in generated switch body. https://github.com/rescript-lang/rescript-compiler/pull/6672
• Fix issue in partial application when the last named arg is provided. https://github.com/rescript-lang/rescript-compiler/pull/6681

:nail-care: Polish

• Omit undefined in external function calls for trailing optional arguments when not supplied. https://github.com/rescript-lang/rescript-compiler/pull/6653
• Make pattern match suggestions to be easier to copy-paste. https://github.com/rescript-lang/rescript-compiler/pull/6656

11.1.0-rc.3

:nail_care: Polish

• No parens around tagged template literals. https://github.com/rescript-lang/rescript-compiler/pull/6639
• Allow identifier with modules in tagged template literals (e.g. Pg.sqlselect * from ${table} where id = ${id}). https://github.com/rescript-lang/rescript-compiler/pull/6645

:bug: Bug Fix

• Fix compiler crash when reexporting tagged template literal externals. https://github.com/rescript-lang/rescript-compiler/pull/6645

11.1.0-rc.2

:rocket: New Feature

• Add support for array spread. https://github.com/rescript-lang/rescript-compiler/pull/6608
• Support import attributes (https://github.com/tc39/proposal-import-attributes) in @module(). https://github.com/rescript-lang/rescript-compiler/pull/6599
• allow hyphens in jsx tag names (e.g. <mj-column>). https://github.com/rescript-lang/rescript-compiler/pull/6609

:bug: Bug Fix

• Fix issue with async and newtype in uncurried mode. https://github.com/rescript-lang/rescript-compiler/pull/6601
• Generic JSX transform: Rename expected module name for lowercase JSX to Elements from DOM. https://github.com/rescript-lang/rescript-compiler/pull/6606
• Generic JSX transform: Set default config params for jsxConfig. https://github.com/rescript-lang/rescript-compiler/pull/6606
• Generic JSX transform: Handle namespaced names. https://github.com/rescript-lang/rescript-compiler/pull/6606
• Fix issue with doc comment in recursive module. https://github.com/rescript-lang/rescript-compiler/pull/6613
• Fix issue with Exceptions and Extensible types runtime generation. https://github.com/rescript-lang/rescript-compiler/pull/6570
• Fix inline comment before spread syntax in record. https://github.com/rescript-lang/rescript-compiler/pull/6615

:house: Internal

• Use OCaml 4.14.1 (+ Alpine 3.19 container) for CI build. https://github.com/rescript-lang/rescript-compiler/pull/6600

11.1.0-rc.1

:rocket: New Feature

• Experimental support of tagged template literals, e.g. sql`select * from ${table}`. https://github.com/rescript-lang/rescript-compiler/pull/6250
• Experimental support for generic/custom JSX transforms. https://github.com/rescript-lang/rescript-compiler/pull/6565
• dict is now a builtin type. https://github.com/rescript-lang/rescript-compiler/pull/6590

:bug: Bug Fix

• GenType: distinguish inline records from unary variant cases of object type. https://github.com/rescript-lang/rescript-compiler/pull/6586

11.0.1

:bug: Bug Fix

• Renamed inline record fields: fix renamed field access in inline records. https://github.com/rescript-lang/rescript-compiler/pull/6551
• Fixed issue with coercions sometimes raising a Not_found instead of giving a proper error message. https://github.com/rescript-lang/rescript-compiler/pull/6574
• Fix issue with recursive modules and uncurried. https://github.com/rescript-lang/rescript-compiler/pull/6575

:nail_care: Polish

• Improve error message for missing label(s) in function application. https://github.com/rescript-lang/rescript-compiler/pull/6576

11.0.0

No changes compared to rc.9.

11.0.0-rc.9

:rocket: New Feature

• GenType: support @deriving(accessors) outputs. https://github.com/rescript-lang/rescript-compiler/pull/6537
• Allow coercing ints and floats to unboxed variants that have a catch-all unboxed int or float case. https://github.com/rescript-lang/rescript-compiler/pull/6540
• Allow tuples in untagged variants. https://github.com/rescript-lang/rescript-compiler/pull/6550

:bug: Bug Fix

• GenType: now emits full suffix on JS import path to be compatible with .res.js. https://github.com/rescript-lang/rescript-compiler/pull/6541

:nail_care: Polish

• Format docstrings. https://github.com/rescript-lang/rescript-compiler/pull/6417
• JSX v4: make automatic mode the default. https://github.com/rescript-lang/rescript-compiler/pull/6552

11.0.0-rc.8

:rocket: New Feature

• Add support for type coercion for invariant type arguments such as array payloads. https://github.com/rescript-lang/rescript-compiler/pull/6518
• Start treating rescript command the same as the rescript build command, so now you can do rescript -w. https://github.com/rescript-lang/rescript-compiler/pull/6524

:bug: Bug Fix

• Fix accidental removal of Belt.Result.Ok and Belt.Result.Error constructors in rc.5. https://github.com/rescript-lang/rescript-compiler/pull/6514
• Add missing check that the runtime representation of variants matches implementation and interface. https://github.com/rescript-lang/rescript-compiler/pull/6513/files
• GenType: only export types (not values) from module types. https://github.com/rescript-lang/rescript-compiler/pull/6516
• Fix compiler crash with unboxed variant definition with only 1 constructor. https://github.com/rescript-lang/rescript-compiler/pull/6523
• GenType: support mutual recursive types inside modules. https://github.com/rescript-lang/rescript-compiler/pull/6528
• Workaround for @as in labels in uncurried externals, which was broken. https://github.com/rescript-lang/rescript-compiler/pull/6527

:nail_care: Polish

• GenType: make outputs DCE-friendly. https://github.com/rescript-lang/rescript-compiler/pull/6508

11.0.0-rc.7

:rocket: New Feature

• Allow empty inline records in variants. https://github.com/rescript-lang/rescript-compiler/pull/6494
• Allow empty record patterns in pattern matching. https://github.com/rescript-lang/rescript-compiler/pull/6494

:bug: Bug Fix

• Fix issue where an inline record with attributes did not parse. https://github.com/rescript-lang/rescript-compiler/pull/6499
• Fix issue with uncurried function with 1 arg being a variable where an undefined variable could be emitted. https://github.com/rescript-lang/rescript-compiler/pull/6507
• Fix runtime errors on @genType.as("alias") output. https://github.com/rescript-lang/rescript-compiler/pull/6509

11.0.0-rc.6

:rocket: New Feature

• Freely configurable suffix for generated .js files. https://github.com/rescript-lang/rescript-compiler/pull/6472

:bug: Bug Fix

• Fix issue with GenType and result introduced in rc.5. https://github.com/rescript-lang/rescript-compiler/pull/6464
• Fix compiler crash when inlining complex constants in pattern matching. https://github.com/rescript-lang/rescript-compiler/pull/6471
• Fix issue with generating async functions inside loops. https://github.com/rescript-lang/rescript-compiler/pull/6479
• Fix issue with Gentype and string annotations with numbers such as @as("0"). https://github.com/rescript-lang/rescript-compiler/pull/6487
• Fix error message on curried/uncurried signature mismatch. https://github.com/rescript-lang/rescript-compiler/pull/6414

:nail_care: Polish

• Improve some error messages in rescript.conf parsing. https://github.com/rescript-lang/rescript-compiler/pull/6469

11.0.0-rc.5

:rocket: New Feature

• Allow coercing unboxed variants with only strings (now including with a single payload of string) to the primitive string. https://github.com/rescript-lang/rescript-compiler/pull/6441
• Allow coercing strings to unboxed variants that have a catch-all unboxed string case. https://github.com/rescript-lang/rescript-compiler/pull/6443
• Allow coercing int to float. https://github.com/rescript-lang/rescript-compiler/pull/6448

:bug: Bug Fix

• Fix issue with dynamic import of module in nested expressions. https://github.com/rescript-lang/rescript-compiler/pull/6431
• Fix issue where GenType was not supporting @tag on ordinary variants. https://github.com/rescript-lang/rescript-compiler/pull/6437
• Fix using dynamic import of module in block instead of async function. https://github.com/rescript-lang/rescript-compiler/pull/6434
• Fix issue with using dynamic import of module in uncurried mode. https://github.com/rescript-lang/rescript-compiler/pull/6434
• Fix build error with JSX v4 transformation of React.forwardRef in uncurried mode. https://github.com/rescript-lang/rescript-compiler/pull/6447
• Fix printing of exotic JSX names. https://github.com/rescript-lang/rescript-compiler/pull/6451
• Fix locations when code with await fails to compile (all locations would point to the internal function unsafe_await). https://github.com/rescript-lang/rescript-compiler/pull/6452
• Fix renaming fields (with @as) in inline records doesn't work when destructuring. https://github.com/rescript-lang/rescript-compiler/pull/6456
• Fix rc.4 regressions:
  • Don't show compilation time when calling rescript build -help command. https://github.com/rescript-lang/rescript-compiler/pull/6439
  • Running rescript build -w with a compilation error doesn't exit with an error code and continues waiting for changes. https://github.com/rescript-lang/rescript-compiler/pull/6460

:house: Internal

• Remove dependency stdlib-406 -> belt. https://github.com/rescript-lang/rescript-compiler/pull/6453
• Playground: Add support for implicitly opened modules. https://github.com/rescript-lang/rescript-compiler/pull/6446

:nail_care: Polish

• Add Deno to reserved names, so that modules named Deno don't clash with the globally exposed Deno object. https://github.com/rescript-lang/rescript-compiler/pull/6428
• Disable ESLint/TSLint on gentype outputs properly. https://github.com/rescript-lang/rescript-compiler/pull/6442
• Improve rescript CLI to use stdout/stderr appropriately for help command's message. https://github.com/rescript-lang/rescript-compiler/pull/6439
• Generate f() instead of f(undefined) for f(). https://github.com/rescript-lang/rescript-compiler/pull/6459

11.0.0-rc.4

:rocket: New Feature

• Support renaming fields in inline records with @as attribute. #6391
• Support renaming object fields of @obj external ppx with @as attribute. #6391
• Add builtin abstract types for File and Blob APIs. https://github.com/rescript-lang/rescript-compiler/pull/6383
• Untagged variants: Support promise, RegExes, Dates, File and Blob. https://github.com/rescript-lang/rescript-compiler/pull/6383
• Untagged variants: Support bool. https://github.com/rescript-lang/rescript-compiler/pull/6368
• Support aliased types as payloads to untagged variants. https://github.com/rescript-lang/rescript-compiler/pull/6394
• Support the async component for React Server Component in JSX V4. https://github.com/rescript-lang/rescript-compiler/pull/6399
• Support rescript.json configuration file and deprecate bsconfig.json. https://github.com/rescript-lang/rescript-compiler/pull/6382

:boom: Breaking Change

• Update watcher rules to recompile only on config and *.res/*.resi/*.ml/.mli file changes. Solves the issue of unnecessary recompiles on .css, .ts, and other unrelated file changes. https://github.com/rescript-lang/rescript-compiler/pull/6420
• Add smart printer for pipe chains. https://github.com/rescript-lang/rescript-compiler/pull/6411 (the formatter will reformat existing code in certain cases)
• Js.Json.t now uses Boolean(bool) instead of explicit @as(true) True | @as(false) False. https://github.com/rescript-lang/rescript-compiler/pull/6421

:bug: Bug Fix

• Fix issue with GenType and labelled arguments. https://github.com/rescript-lang/rescript-compiler/pull/6406
• Fix dependencies reinitialization on every change in watch mode. Leads to faster rebuilds and cleaner terminal. https://github.com/rescript-lang/rescript-compiler/pull/6404

:nail_care: Polish

• A little performance improvement for JSX V4 runtime helper by removing one object allocation for components with key prop. https://github.com/rescript-lang/rescript-compiler/pull/6376
• The error message for "toplevel expressions should evaluate to unit" has been revamped and improved. https://github.com/rescript-lang/rescript-compiler/pull/6407
• Improve "Somewhere wanted" error messages by changing wording and adding more context + suggested solutions to the error messages where appropriate. https://github.com/rescript-lang/rescript-compiler/pull/6410
• Display the compile time for rescript build command. https://github.com/rescript-lang/rescript-compiler/pull/6404
• Improve help message for build and clean commands. https://github.com/rescript-lang/rescript-compiler/pull/6404
• Pass through the -verbose flag to builds in watch mode. https://github.com/rescript-lang/rescript-compiler/pull/6404
• Improve error message when defining duplicate labels in a record. https://github.com/rescript-lang/rescript-compiler/pull/6415
• Improve error message when trying to concatenate strings using the wrong operator. https://github.com/rescript-lang/rescript-compiler/pull/6416

11.0.0-rc.3

:bug: Bug Fix

• Fix issue with JSX V4 when component props have the default value with same name. https://github.com/rescript-lang/rescript-compiler/pull/6377
• Fixed code formatter with "uncurried": false in bsconfig. https://github.com/rescript-lang/rescript-compiler/pull/6378

:nail_care: Polish

• Add Bun to reserved names, so that modules named Bun don't clash with the globally exposed Bun object. https://github.com/rescript-lang/rescript-compiler/pull/6381

11.0.0-rc.2

:rocket: New Feature

• rescript build will always build its dependency by default. The argument -with-deps is not needed anymore. https://github.com/rescript-lang/rescript-compiler/pull/6350

:boom: Breaking Change

• Stop mangling object field names. If you had objects with field names containing "__" or leading "_", they won't be mangled in the compiled JavaScript and represented as it is without changes. https://github.com/rescript-lang/rescript-compiler/pull/6354

:bug: Bug Fix

• Fixed outcome printer resolution of uncurried config. https://github.com/rescript-lang/rescript-compiler/pull/6353

11.0.0-rc.1

:rocket: New Feature

• GenType: Propagate comments from record fields to emitted TypeScript types. https://github.com/rescript-lang/rescript-compiler/pull/6333

:boom: Breaking Change

• $$default is no longer exported from the generated JavaScript when using default exports. https://github.com/rescript-lang/rescript-compiler/pull/6328

:nail_care: Polish

• Conditionally print error message about record with missing label potentially being a component. https://github.com/rescript-lang/rescript-compiler/pull/6337
• Put definition in the bottom and the actual error at the top when reporting errors for supplying fields etc with the wrong name. https://github.com/rescript-lang/rescript-compiler/pull/6336
• Fix left over places where polyvariant tag names were printed in OCaml syntax instead of ReScript. https://github.com/rescript-lang/rescript-compiler/pull/6348

11.0.0-beta.4

:rocket: New Feature

• Variants: Allow coercing from variant to variant where applicable. https://github.com/rescript-lang/rescript-compiler/pull/6314
• Variants: Experimental support for spreading variant type definitions to copy constructors from one variant to another. https://github.com/rescript-lang/rescript-compiler/pull/6316

:boom: Breaking Change

• Fixed name collision between the newly defined Js.Json.t and the variant constructor in the existing Js.Json.kind type. To address this, the usage of the existing Js.Json.kind type can be updated to Js.Json.Kind.t. https://github.com/rescript-lang/rescript-compiler/pull/6317

:bug: Bug Fix

• Fixed outcome printing of uncurried higher order function types. https://github.com/rescript-lang/rescript-compiler/pull/6323
• Fixed printing of type constraints in template literal substitutions. https://github.com/rescript-lang/rescript-compiler/pull/6324

11.0.0-beta.3

:rocket: New Feature

• Untagged variants: consider regexp as an object type. https://github.com/rescript-lang/rescript-compiler/pull/6296
• Semantic-based optimization of code generated for untagged variants. https://github.com/rescript-lang/rescript-compiler/issues/6108
• Record type spreads: Allow using type variables in type spreads. Both uninstantiated and instantiated ones. https://github.com/rescript-lang/rescript-compiler/pull/6309
• Variants: Allow coercing variants to string/int/float when applicable. https://github.com/rescript-lang/rescript-compiler/pull/6311

:bug: Bug Fix

• Fix issue with dynamic import of modules in expressions. https://github.com/rescript-lang/rescript-compiler/pull/6310

11.0.0-beta.2

:rocket: New Feature

• Introduced a new %ffi extension (experimental - not for production use!) that provides a more robust mechanism for JavaScript function interoperation by considering function arity in type constraints. This enhancement improves safety when dealing with JavaScript functions by enforcing type constraints based on the arity of the function. https://github.com/rescript-lang/rescript-compiler/pull/6251
• Extended untagged variants with function types. https://github.com/rescript-lang/rescript-compiler/pull/6279

:boom: Breaking Change

• Remove rudimentary node bindings and undocumented %node extension. https://github.com/rescript-lang/rescript-compiler/pull/6285

:bug: Bug Fix

• Fix issue where uncurried type internals leak in type error. https://github.com/rescript-lang/rescript-compiler/pull/6264
• Improve error messages for untagged variant definition. https://github.com/rescript-lang/rescript-compiler/pull/6290
• Fix type checking performance issue for large records. https://github.com/rescript-lang/rescript-compiler/pull/6289

11.0.0-beta.1

:rocket: Main New Feature

• Make uncurried mode opt-out: by default, every project is now in uncurried mode, unless "uncurried": false is specified in the project config. https://github.com/rescript-lang/rescript-compiler/pull/6249

:nail_care: Polish

• Removed duplicate Super_error implementation in syntax. https://github.com/rescript-lang/rescript-compiler/pull/6246

:bug: Bug Fix

• Fix issue with inlining records in the presence of record coercion. https://github.com/rescript-lang/rescript-compiler/pull/6256

11.0.0-alpha.6

:boom: Breaking Change

• -bs-super-errors flag has been deprecated along with Super_errors. https://github.com/rescript-lang/rescript-compiler/pull/6243
• @rescript/react >= 0.12.0-alpha.2 is now required because of the React.fragment's children type fix. https://github.com/rescript-lang/rescript-compiler/pull/6238

:bug: Bug Fix

• Remove unnecessary require and import statements when using dynamic imports. https://github.com/rescript-lang/rescript-compiler/pull/6232
• Fix option unboxing logic in the presence of untagged variants. https://github.com/rescript-lang/rescript-compiler/pull/6233
• Fix printing of local module with type. https://github.com/rescript-lang/rescript-compiler/issues/6212
• Adapting JSX4 to React.fragment's children type change ('children -> React.element) https://github.com/rescript-lang/rescript-compiler/pull/6238

:nail_care: Polish

• In uncurried mode, outcome printer swaps curried and uncurries function printing compared to legacy.
• Add location information to duplicate type definition error messages. https://github.com/rescript-lang/rescript-compiler/pull/6199
• Replace normal module errors with Super_error module, and clean up Super_error. https://github.com/rescript-lang/rescript-compiler/pull/6199
• Js.Json.t, Js.null and Js.nullable are now untagged variants representing their runtime values, instead of abstract types. https://github.com/rescript-lang/rescript-compiler/pull/6218

11.0.0-alpha.5

:rocket: Main New Feature

• Add support for Dynamic import. https://github.com/rescript-lang/rescript-compiler/pull/5703
• GenType: Add moduleResolution option to customize extensions on emitted import statements. This helps to adjust output compatibility with TypeScript projects using ESM. https://github.com/rescript-lang/rescript-compiler/pull/6182
  • node (default): Drop extensions.
  • node16: Use TS output's extensions. Make it ESM-compatible.
  • bundler: Use TS input's extensions. Make it ESM-compatible.
• Make untagged variants understand payloads defined as records. https://github.com/rescript-lang/rescript-compiler/pull/6208

:boom: Breaking Change

• Parse assert as a regular function. assert is no longer a unary expression. Example: before assert 1 == 2 is parsed as (assert 1) == 2, now it is parsed as assert(1 == 2). https://github.com/rescript-lang/rescript-compiler/pull/6180

:bug: Bug Fix

• Make "rescript format" work with node 10 again and set minimum required node version to 10 in package.json. https://github.com/rescript-lang/rescript-compiler/pull/6186
• Fix partial application for uncurried functions with labeled args https://github.com/rescript-lang/rescript-compiler/pull/6198
• Add error messages for dangling doc comments/attributes and mutable in record type definition. https://github.com/rescript-lang/rescript-compiler/pull/6206
• Fix issue with overlapping array and object in untagged variants https://github.com/rescript-lang/rescript-compiler/pull/6219

11.0.0-alpha.4

:rocket: Main New Feature

• Add surface syntax for partial application of uncurried functions: foo(1, ...). This corresponds to curried application in the old mode. https://github.com/rescript-lang/rescript-compiler/pull/6166

:bug: Bug Fix

• Fix broken formatting in uncurried mode for functions with _ placeholder args. https://github.com/rescript-lang/rescript-compiler/pull/6148
• Fix issue where spreading record types with optional labels would not have their labels preserved as optional. https://github.com/rescript-lang/rescript-compiler/pull/6154
• Fix error location to be the type with the spreads when spreading record types with duplicate labels. https://github.com/rescript-lang/rescript-compiler/pull/6157
• Disable warning on @inline attibute on uncurried functions. https://github.com/rescript-lang/rescript-compiler/pull/6152
• Support doc comments on arguments of function types. https://github.com/rescript-lang/rescript-compiler/pull/6161
• Fix issue with record type coercion and unboxed. https://github.com/rescript-lang/rescript-compiler/issues/6158
• Fixed subtype checking for record types with "@as" attributes: The subtype relationship now takes into account the compatibility of "@as" attributes between corresponding fields, ensuring correctness in runtime representation. https://github.com/rescript-lang/rescript-compiler/issues/6158
• Emit directive above header comment. https://github.com/rescript-lang/rescript-compiler/pull/6172
• Add error message to private extension. https://github.com/rescript-lang/rescript-compiler/pull/6175

:nail_care: Polish

• Update list of reserved JS keywords. https://github.com/rescript-lang/rescript-compiler/pull/6167
• Add error message to @@directive. https://github.com/rescript-lang/rescript-compiler/pull/6174

11.0.0-alpha.3

:rocket: Main New Feature

• Add support for extensible records (e.g. type t = {...t1, x:int, ...t2}) https://github.com/rescript-lang/rescript-compiler/pull/5715

:bug: Bug Fix

• Fix formatting and parentheses placement in uncurried functions with constraints. https://github.com/rescript-lang/rescript-compiler/pull/6143

11.0.0-alpha.2

:rocket: Main New Feature

• Add support for type coercion :> for records. https://github.com/rescript-lang/rescript-compiler/pull/5721

:bug: Bug Fix

• Special case generation of uncurried functions with 1 argument of unit type so they don't take a parameter. https://github.com/rescript-lang/rescript-compiler/pull/6131

11.0.0-alpha.1

:rocket: Main New Feature

• Introduce experimental uncurried mode. For experimentation only. PR #5796
• Customization of runtime representation of variants and introduction of untagged variants PR #6095, PR #6103

:rocket: New Feature

• Add support for uncurried mode: a mode where everything is considered uncurried, whether with or without the .. This can be turned on with @@uncurried locally in a file. For project-level configuration in bsconfig.json, there's a boolean config "uncurried", which propagates to dependencies, to turn on uncurried mode. Since there's no syntax for partial application in this new mode, introduce @res.partial foo(x) to express partial application. This is temporary and will later have some surface syntax. Make uncurried functions a subtype of curried functions, and allow application for uncurried functions. The make function of components is generated as an uncurried function. Use best effort to determine the config when formatting a file. https://github.com/rescript-lang/rescript-compiler/pull/5968 https://github.com/rescript-lang/rescript-compiler/pull/6080 https://github.com/rescript-lang/rescript-compiler/pull/6086 https://github.com/rescript-lang/rescript-compiler/pull/6087
• Customization of runtime representation of variants. This is work in progress. E.g. some restrictions on the input. See comments of the form "TODO: put restriction on the variant definitions allowed, to make sure this never happens". https://github.com/rescript-lang/rescript-compiler/pull/6095
• Introduce untagged variants https://github.com/rescript-lang/rescript-compiler/pull/6103
• Add support for unary uncurried pipe in uncurried mode https://github.com/rescript-lang/rescript-compiler/pull/5804
• Add support for partial application of uncurried functions: with uncurried application one can provide a subset of the arguments, and return a curried type with the remaining ones https://github.com/rescript-lang/rescript-compiler/pull/5805
• Add support for uncurried externals https://github.com/rescript-lang/rescript-compiler/pull/5815 https://github.com/rescript-lang/rescript-compiler/pull/5819 https://github.com/rescript-lang/rescript-compiler/pull/5830 https://github.com/rescript-lang/rescript-compiler/pull/5894
• Parser/Printer: unify uncurried functions of arity 0, and of arity 1 taking unit. There's now only arity 1 in the source language. https://github.com/rescript-lang/rescript-compiler/pull/5825
• Add support for default arguments in uncurried functions https://github.com/rescript-lang/rescript-compiler/pull/5835
• Inline uncurried application when it is safe https://github.com/rescript-lang/rescript-compiler/pull/5847
• Support optional named arguments without a final unit in uncurried functions https://github.com/rescript-lang/rescript-compiler/pull/5907
• GenType: add the option to use the @genType annotation at the module level, meaning that all the items in the module should be exported. https://github.com/rescript-lang/rescript-compiler/pull/6113
• GenType: add support for @genType annotations on module definitions. https://github.com/rescript-lang/rescript-compiler/pull/6113
• Prebuilt binaries are now provided for all major platforms:
  • macOS x64
  • macOS ARM
  • Linux x64 (statically linked)
  • Linux ARM (statically linked)
  • Windows x64

:boom: Breaking Change

• Remove support for the legacy Reason syntax. Existing Reason code can be converted to ReScript syntax using ReScript 9 as follows:
  • npm i -g rescript@9
  • rescript convert <reason files>
• Remove obsolete built-in project templates and the "rescript init" functionality. This is replaced by create-rescript-app which is maintained separately.
• Do not attempt to build ReScript from source on npm postinstall for platforms without prebuilt binaries anymore.
• Made pinned dependencies transitive: if a is a pinned dependency of b and b is a pinned dependency of c, then a is implicitly a pinned dependency of c. This change is only breaking if your build process assumes non-transitivity.
• Curried after uncurried is not fused anymore: (. x) => y => 3 is not equivalent to (. x, y) => 3 anymore. It's instead equivalent to (. x) => { y => 3 }. Also, (. int) => string => bool is not equivalen to (. int, string) => bool anymore. These are only breaking changes for unformatted code.
• Exponentiation operator ** is now right-associative. 2. ** 3. ** 2. now compile to Math.pow(2, Math.pow(3, 2)) and not anymore Math.pow(Math.pow(2, 3), 2). Parentheses can be used to change precedence.
• Remove unsafe j`$(a)$(b)` interpolation deprecated in compiler version 10 https://github.com/rescript-lang/rescript-compiler/pull/6068
• Remove deprecated module Printexc
• @deriving(jsConverter) not supported anymore for variant types https://github.com/rescript-lang/rescript-compiler/pull/6088
• New representation for variants, where the tag is a string instead of a number. https://github.com/rescript-lang/rescript-compiler/pull/6088
• GenType: removed support for @genType.as for records and variants which has become unnecessary. Use the language's @as instead to channge the runtime representation without requiring any runtime conversion during FFI. https://github.com/rescript-lang/rescript-compiler/pull/6099 https://github.com/rescript-lang/rescript-compiler/pull/6101

:bug: Bug Fix

• Fix issue where uncurried was not supported with pipe https://github.com/rescript-lang/rescript-compiler/pull/5803
• Fix printing of nested types in uncurried mode https://github.com/rescript-lang/rescript-compiler/pull/5826
• Fix issue in printing uncurried callbacks https://github.com/rescript-lang/rescript-compiler/pull/5828
• Fix formatting uncurried functions with attributes https://github.com/rescript-lang/rescript-compiler/pull/5829
• Fix parsing/printing uncurried functions with type parameters https://github.com/rescript-lang/rescript-compiler/pull/5849
• Fix compiler ppx issue when combining async and uncurried application https://github.com/rescript-lang/rescript-compiler/pull/5856
• Fix issue where the internal representation of uncurried types would leak when a non-function is applied in a curried way https://github.com/rescript-lang/rescript-compiler/pull/5892
• Fix some comments disappearing in array access expressions https://github.com/rescript-lang/rescript-compiler/pull/5947
• Parser: fix location of variable when function definition {v => ...} is enclosed in braces https://github.com/rescript-lang/rescript-compiler/pull/5949
• Fix issue with error messages for uncurried functions where expected and given type were swapped https://github.com/rescript-lang/rescript-compiler/pull/5973
• Fix issue with integer overflow check https://github.com/rescript-lang/rescript-compiler/pull/6028
• Make internal encoding of locations aware of unicode https://github.com/rescript-lang/rescript-compiler/pull/6073
• Fix issue where foo(x,_) in uncurried mode would generate a curried function https://github.com/rescript-lang/rescript-compiler/pull/6082
• Fix printing of uncurried application when the lhs is a function definition https://github.com/rescript-lang/rescript-compiler/pull/6084
• Fix parsing uncurried type starting with path https://github.com/rescript-lang/rescript-compiler/pull/6089
• Fix bigInt comparison https://github.com/rescript-lang/rescript-compiler/pull/6097
• Fixed a bug where the async attribute was not preserved when using the @this decorator in ReScript functions. This fix allows proper handling of async functions with the @this decorator. Issue: https://github.com/rescript-lang/rescript-compiler/issues/6100
• Fix issue with GenType and module aliases https://github.com/rescript-lang/rescript-compiler/issues/6112

:nail_care: Polish

• Syntax: process uncurried types explicitly in the parser/printer https://github.com/rescript-lang/rescript-compiler/pull/5784 https://github.com/rescript-lang/rescript-compiler/pull/5822
• Syntax: process uncurried function declarations explicitly in the parser/printer https://github.com/rescript-lang/rescript-compiler/pull/5794
• PPX V4: allow uncurried make function and treat it like a curried one #5802 #5808 #5812
• Remove processing of objects expressions, which don't exist in .res syntax (Pexp_object) https://github.com/rescript-lang/rescript-compiler/pull/5841
• Remove class type processing from compiler ppx https://github.com/rescript-lang/rescript-compiler/pull/5842
• Remove method application via operator ##, which does not exist in .res syntax https://github.com/rescript-lang/rescript-compiler/pull/5844
• Treat @meth annotation as making the type uncurried for backwards compatibitly with some examples https://github.com/rescript-lang/rescript-compiler/pull/5845
• Process @set annotation for field update as generating an uncurried function https://github.com/rescript-lang/rescript-compiler/pull/5846
• Treat uncurried application of primitives like curried application, which produces better output https://github.com/rescript-lang/rescript-compiler/pull/5851
• New internal representation for uncurried functions using built-in type function$<fun_type, arity> this avoids having to declare all the possible arities ahead of time https://github.com/rescript-lang/rescript-compiler/pull/5870
• PPX V3: allow uncurried make function and treat it like a curried one https://github.com/rescript-lang/rescript-compiler/pull/6081
• Add support for |> in uncurried mode by desugaring it https://github.com/rescript-lang/rescript-compiler/pull/6083
• Change the compilation of pattern matching for variants so it does not depends on variats being integers https://github.com/rescript-lang/rescript-compiler/pull/6085
• Improve code generated for string templates https://github.com/rescript-lang/rescript-compiler/pull/6090
• Move Jsx and JsxDOM and JsxEvent and JsxPPXReactSupport inside Pervasives and build them separately for curried and uncurried mode https://github.com/rescript-lang/rescript-compiler/pull/6091
• Gentype: allow recursive data types https://github.com/rescript-association/genType/issues/585

10.1.4

:bug: Bug Fix

• Fix implementation of directives https://github.com/rescript-lang/rescript-compiler/pull/6052
• Fix issue if the lib dir is included in the sources of bsconfig.json https://github.com/rescript-lang/rescript-compiler/pull/6055
• Fix issue with string escape in pattern match https://github.com/rescript-lang/rescript-compiler/pull/6062
• Fix issue with literal comparison of string constants https://github.com/rescript-lang/rescript-compiler/pull/6065

:rocket: New Feature

• Add support for toplevel await https://github.com/rescript-lang/rescript-compiler/pull/6054

:nail_care: Polish

• Better error message for extension point https://github.com/rescript-lang/rescript-compiler/pull/6057
• Improve format check help https://github.com/rescript-lang/rescript-compiler/pull/6056
• Deprecate unsafe j`$(a)$(b)` interpolation: use string templates `${a}${b}` instead https://github.com/rescript-lang/rescript-compiler/pull/6067

10.1.3

:rocket: New Feature

• Add experimental suppport for directives. An annotation such as @@directive("use client;") emits use client; verbatim before imports https://github.com/rescript-lang/rescript-compiler/pull/5999
• genType: add Core standard library support for the following builtin types: Null.t, Nullable.t, Undefined.t, Dict.t<_>, Promise.t<_>, Date.t, BigInt.t, RegExp.t, Map.t<_, _>, WeakMap.t<_, _>, Set<_>, WeakSet<_> https://github.com/rescript-lang/rescript-compiler/pull/6024

:boom: Breaking Change

• genType: streamline the treatment of optionals as undefined https://github.com/rescript-lang/rescript-compiler/pull/6024
  • Represent option<t> as undefined | t instead of null | undefined | t. This is more permissive when importing functions taking optional values (allows to use option types), but stricter when e.g. exporting ReScript functions taking arguments of option type. Fallback: use Js.undefined<_> instead.
  • Represent {x:option<string>} as {x:(undefined | string)} instead of {x?: string}. This is more in line with TS's behaviour. Fallback: use {x?:string}.

:nail_care: Polish

• Add the gap property to jsxDOMStyle https://github.com/rescript-lang/rescript-compiler/pull/5956

:bug: Bug Fix

• Fix issue where error messages related to non-existent props were displayed without location information https://github.com/rescript-lang/syntax/pull/730
• Fix issue where uncurried functions were incorrectly converting the type of a prop given as a default value to curried https://github.com/rescript-lang/syntax/pull/731
• Fix issue with nested async functions, where the inner function would be emitted without async https://github.com/rescript-lang/rescript-compiler/pull/5984
• Fix issue with printing async functions with locally abstract types https://github.com/rescript-lang/syntax/pull/732
• Fix issue with async context and locally abstract types https://github.com/rescript-lang/rescript-compiler/pull/5985
• Fix support for recursive components in JSX V4 https://github.com/rescript-lang/syntax/pull/733
• GenType: fix issue with V3 compatibility mode (see https://github.com/rescript-lang/rescript-compiler/issues/5990) https://github.com/rescript-lang/rescript-compiler/pull/5992
• Fix issue with overlapping labelled argument with default value https://github.com/rescript-lang/syntax/pull/734
• Fix issue with using alias and default value together https://github.com/rescript-lang/syntax/pull/734
• Fix issue in Js.Promise2 where then and catch were returning undefined https://github.com/rescript-lang/rescript-compiler/pull/5996
• Fix issue in the compiler back-end where async functions passed to an @uncurry external would be inlined and transformed in a way that loses async https://github.com/rescript-lang/rescript-compiler/pull/6011
• Fix location issue for the treatment of async functions where hovering on the body with a type error would show 'a => promise<'a> everywhere https://github.com/rescript-lang/rescript-compiler/pull/6014
• Fix formatting of switch expressions that contain braced cases inside https://github.com/rescript-lang/syntax/pull/735
• Fix formatting of props spread for multiline JSX expression https://github.com/rescript-lang/syntax/pull/736
• Support @gentype.import as an alias to @genType.import in the compiler https://github.com/rescript-lang/rescript-compiler/pull/6021
• In GenType, check annotations also in module types to decide whether to produce the .gen.tsx file https://github.com/rescript-lang/rescript-compiler/pull/5903
• Fix issue with JSX V4 and newtype https://github.com/rescript-lang/syntax/pull/737
• Fix issue with JSX V4 when components are nested https://github.com/rescript-lang/syntax/pull/738
• Fix issue where generic compare on float values would be different from the compare for type float https://github.com/rescript-lang/rescript-compiler/pull/6043
• Improve code generated for default arguments in JSX V4 https://github.com/rescript-lang/syntax/pull/739
• Fix issue with JSX V4 props of the form ~p as module(...) https://github.com/rescript-lang/syntax/pull/739

10.1.2

:bug: Bug Fix

• Fix an issue where error messages related to duplicate props were displayed without a loc and were unclear https://github.com/rescript-lang/syntax/pull/728

10.1.1

:boom: Breaking Change

• Parse the attributes of labelled argument to the pattern attributes of argument instead of function. https://github.com/rescript-lang/syntax/pull/722
• The prop names duplicated to keyword are not mangled automatically in JSX v4.
  • Use @as instead

:rocket: New Feature

• Add support for empty inlined record literal {} for inlined records where all fields are optional https://github.com/rescript-lang/rescript-compiler/pull/5900

:bug: Bug Fix

• Prevent inlining of async functions in additional cases https://github.com/rescript-lang/rescript-compiler/issues/5860
• Fix build error where aliasing arguments to _ in the make function with JSX V4. https://github.com/rescript-lang/rescript-compiler/pull/5881
• Fix parsing of spread props as an expression in JSX V4 https://github.com/rescript-lang/rescript-compiler/pull/5885
• Fix dropping attributes from props in make function in JSX V4 https://github.com/rescript-lang/rescript-compiler/pull/5905

10.1.0

:bug: Bug Fix

• Fix issue where no error was reported when ? was used for non-optional fields. https://github.com/rescript-lang/rescript-compiler/pull/5853
• Fix issue where optional fields in inline records were not supported and would cause type errors https://github.com/rescript-lang/rescript-compiler/pull/5827

10.1.0-rc.5

:bug: Bug Fix

• Prevent inlining of async functions in last stage of the compiler when the functions are not exported (not in interface file or shadowed) https://github.com/rescript-lang/rescript-compiler/pull/5790

10.1.0-rc.4

:rocket: New Feature

• Support format check with rescript format -check. https://github.com/rescript-lang/rescript-compiler/pull/5760

:bug: Bug Fix

• Fix issue where the last line of rescript format --help usage was being swallowed https://github.com/rescript-lang/rescript-compiler/pull/5760
• Specialize the printing of the rhs of a record field assignment for optional values {x: ? e} https://github.com/rescript-lang/syntax/issues/714

10.1.0-rc.3

:rocket: New Feature

• Support the use of spread anywhere in list creation (e.g. list{...x, 1, ...y, ...z}). https://github.com/rescript-lang/syntax/pull/692
• Add support for the argument of @react.component to set a props type from the outside. https://github.com/rescript-lang/syntax/pull/699

:bug: Bug Fix

• Fix issue where the JSX key type is not an optional string https://github.com/rescript-lang/syntax/pull/693
• Prevent inlining of async functions https://github.com/rescript-lang/rescript-compiler/issues/5754
• Fix build error for JSX fragment without children https://github.com/rescript-lang/syntax/pull/704
• Fix issue where async as an id cannot be used with application and labelled arguments https://github.com/rescript-lang/syntax/issues/707
• Fix 5557: the exhaustive checking for char is incorrect during the unicode migration https://github.com/rescript-lang/rescript-compiler/pull/5749
• Fix 5753: the comment for unicode char is inaccurate https://github.com/rescript-lang/syntax/pull/709
• Treat await as almost-unary operator weaker than pipe so await foo->bar means await (foo->bar) https://github.com/rescript-lang/syntax/pull/711

:nail_care: Polish

• Change payload of Pconst_char from char to int https://github.com/rescript-lang/syntax/pull/709

10.1.0-rc.2

:bug: Bug Fix

• Fix issue with changes not being applied with React Native's Metro bundler for files with warnings https://github.com/rescript-lang/rescript-compiler/pull/5738
• Fix emitting unary minus for floats in case of negative constants https://github.com/rescript-lang/rescript-compiler/pull/5737
• Fix issue where a spread ...x in non-last position would not be reported as syntax error https://github.com/rescript-lang/syntax/pull/673/
• Fix issue where the formatter would delete async in a function with labelled arguments.
• Fix several printing issues with async including an infinite loop https://github.com/rescript-lang/syntax/pull/680
• Fix issue where certain JSX expressions would be formatted differenctly in compiler 10.1.0-rc.1 https://github.com/rescript-lang/syntax/issues/675
• Fix issue where printing nested pipe discards await https://github.com/rescript-lang/syntax/issues/687

10.1.0-rc.1

:boom: Breaking Change

• Deprecate DOM element attributes in JsxDOM.domProps: begin_, end_, to_
  • Use begin, end, to instead.
• Emit an error when a @string or @int attribute is used in a V4 component https://github.com/rescript-lang/rescript-compiler/issues/5724

:rocket: New Feature

• Add extra variants for output filename suffixes in bsconfig.json: .bs.mjs and .bs.cjs are allowed https://github.com/rescript-lang/rescript-compiler/pull/5631
• Safe promises: t-first Js.Promise2 bindings, and remove warning for nested promises https://github.com/rescript-lang/rescript-compiler/pull/5709

:bug: Bug Fix

• Fix issue where uncurried async functions were emitted without async https://github.com/rescript-lang/rescript-compiler/pull/5718
• Fix location issue in error messages with JSX V4 where the multiple props types are defined https://github.com/rescript-lang/syntax/pull/655
• Fix location issue in make function in JSX V4 that breaks dead code elimination https://github.com/rescript-lang/syntax/pull/660
• Fix parsing (hence pretty printing) of expressions with underscore _ and comments.
• Fix printing of comments inside JSX tag https://github.com/rescript-lang/syntax/pull/664
• Fix issue where formatter erases tail comments inside JSX tag https://github.com/rescript-lang/syntax/issues/663
• Fix issue where the JSX prop has type annotation of the first class module https://github.com/rescript-lang/syntax/pull/666
• Fix issue where an empty record literal {} expected to have a non-record type would type check https://github.com/rescript-lang/rescript-compiler/pull/5729

:eyeglasses: Spec Compliance

• Functions with consecutive dots now print as multiple arrow functions like in JavaScript.

:nail_care: Polish

• Add loading, aria-* DOM element attributes in JsxDOM.domProps: ariaCurrent, ariaInvalid, ariaAutocomplete, etc.
• Change the internal representation of props for the lowercase components to record. https://github.com/rescript-lang/syntax/pull/665
• Add JsxPPXReactSupport module to relocate the helper functions for JSX v4 from rescript-react

10.1.0-alpha.2

:rocket: New Feature

• Fix pretty printer where it would print doc comments on the same line as other attributes https://github.com/rescript-lang/syntax/pull/642
• Propagte "jsx" configuration to dependencies https://github.com/rescript-lang/rescript-compiler/pull/5661
• Add support for empty record literal {} for records where all fields are optional https://github.com/rescript-lang/rescript-compiler/pull/5658
• Add support for empty record type (e.g. type empty = {}) https://github.com/rescript-lang/rescript-compiler/pull/5658

:bug: Bug Fix

• Fix issue in formatting JSX spread props https://github.com/rescript-lang/syntax/pull/644
• Fix location issue in error messages with JSX V4 where the body of the component is an application https://github.com/rescript-lang/syntax/pull/633
• Fix printing of type declarations in error message where they would be considered recursive by default
• Fix issue where the printer would omit attributes for -> and |> https://github.com/rescript-lang/syntax/pull/629
• Fix printing of optional fields in records https://github.com/rescript-lang/rescript-compiler/issues/5654
• Fix printing of comments inside empty blocks https://github.com/rescript-lang/syntax/pull/647

:nail_care: Polish

• Improvements and fixes for JSX V4. See guide https://github.com/rescript-lang/syntax/blob/master/cli/JSXV4.md
• Mention all missing fields in error message for records, not just one https://github.com/rescript-lang/rescript-compiler/pull/5657

10.1.0-alpha.1

:boom: Breaking Change

• Pipe -> does not support a code block on the right-hand side e.g. x->{ open A; get("test") }

:rocket: New Feature

• Experimental support for for async/await https://github.com/rescript-lang/rescript-compiler/pull/5537
• Make promise a built-in type https://github.com/rescript-lang/rescript-compiler/pull/5650
• Initial support for JSX V4 including genType, still work in progress.
  • :boom: when V4 is activated, at most one component is allowed for each module.
• Add placeholder types for ES6 collections: Set, Map, WeakSet, and WeakMap https://github.com/rescript-lang/rescript-compiler/pull/5630

:bug: Bug Fix

• Fix issue with arrays and creation of recursive values https://github.com/rescript-lang/rescript-compiler/pull/5640
• Fix issue where characters such as newlines would be escaped in a template string expression https://github.com/rescript-lang/rescript-compiler/issues/5638
• Fix issue where pipe -> processing eats up attributes https://github.com/rescript-lang/rescript-compiler/pull/5581
• Fix issue where cancelling rescript build would leave the .bsb.lock file behind and block future builds

:nail_care: Polish

• Print patterns in warnings using rescript printer https://github.com/rescript-lang/rescript-compiler/pull/5492

10.0.1

:bug: Bug Fix

• Fix issue where watch mode would give an error on Windows https://github.com/rescript-lang/rescript-compiler/pull/5621

10.0.0

Compiler

:boom: Breaking Change

• bsconfig.json does not support // line comments anymore.
  • Example: "suffix": ".bs.js" // determine the suffix
  • Fix: remove the comment and use standard json.
• Changed return type of Js.String.match_ as it was wrong. #5070
  • Example: any use of Js.String.match_ and Js.String2.match_
  • Fix: follow the type errors
• GenType is now vendored in the compiler and drops support for the Flow and untyped back-ends to focus on providing a better experience for TypeScript.
  • Fix: keep on using the older version of the compiler and the separate genType package if Flow support is required. Migrate to TS if one wants to upgrade the compiler version.

:rocket: New Feature

• New records with optional fields e.g. type opt = {x: int, y?: string} were added as an experimental feature #5423 #5452 New Syntax
• Add support for @new @variadic (see https://github.com/rescript-lang/rescript-compiler/pull/5364)

:bug: Bug Fix

• Classify bigint correctly #5351
• Fixed crash in rescript build on Windows #5516
• Fixed rescript init command not working #5526
• Fix issue with compiler log not terminated that causes problems with editor extension not clearing issues when fixed #5545

:nail_care: Polish

• Changed Linux build to depend on GLIBC 2.28 again for compatibility with Debian 10.

• Proper M1 support (CI now supports M1 native builds)

Syntax

:boom: Breaking Change

• @bs.send.pipe is now removed. Earlier it was deprecated.
• Missing labels in function application is now an error (https://forum.rescript-lang.org/t/ann-more-strict-checks-in-missed-labels/2117).
  • Example: let f = (x, ~z) => x + z; f(1, 2)
  • Fix: do let f = (x, ~z) => x + z; f(1, ~z=2) instead
• Externals without @val annotations do not work anymore, and externals with = "" give an error.
  • Example: external setTimeout: (unit => unit, int) => float = "setTimeout" is not supported anymore.
  • Fix: use @val external setTimeout: (unit => unit, int) => float = "setTimeout" instead.
  • Example2: @val external setTimeout: (unit => unit, int) => float = "" is not supported anymore.
  • Fix2: use @val external setTimeout: (unit => unit, int) => float = "setTimeout" instead.
• Strings processed at compile-time don't need escaping anymore.
  • Example: let blockCommentsRe = %re("/\\/\\*([^*]|[\\r\\n]|(\\*+([^*/]|[\\r\\n])))*\\*+\\//g").
  • Fix: use let blockCommentsRe = %re("/\/\*([^*]|[\r\n]|(\*+([^*/]|[\r\n])))*\*+\//g") instead.
• Remove parsing of "import" and "export" which was never officially supported https://github.com/rescript-lang/syntax/pull/597 https://github.com/rescript-lang/syntax/pull/599
  • Example: export type t = int
  • Fix: @genType type t = int
  • Example2: import realValue: complexNumber => float from "./MyMath"
  • Fix2: @genType.import("./MyMath") external realValue: complexNumber => float = "realValue"

:rocket: New Feature

• Unicode is now supported in regular strings and chars (when the symbol fits). This is now going to work: let str = "Σ". And, you'll be able to pattern match on unicode chars: switch c { | 'Σ' => "what a fine unicode char" | _ => "unicode is fun" }
• Doc comments /** ... */ are now supported. Inernally, they are attributes, so are only valid at positions where @foo is allowed, or a syntax error is given. Similarly for module-level /*** comments */ that can go where @@attributes go.

:bug: Bug Fix

• Fix printing for inline nullary functor types #477
• Fix stripping of quotes for empty poly variants #474
• Implement syntax for arity zero vs arity one in uncurried application in #139
• Fix parsing of first class module exprs as part of binary/ternary expr in #256
• Fix formatter hanging on deeply nested function calls #261

Libraries

:boom: Breaking Change

• "Attributes not allowed here". If you see this error chances are you're using a ppx that needs updating to a new version. See an exampe of how to update a ppx
  • Example: for rescript-relay 0.23.0 is not supported.
  • Fix: use rescript-relay@beta or the new version when released.
• Removed printing modules (Printf, Format etc) and related functions. Details of files added/removed: https://github.com/rescript-lang/rescript-compiler/commit/0fd8bb0e77c4b0e96a9647ac8af614305057003f.

:bug: Bug Fix

• Fix library issue with missing bytes_to_string https://github.com/rescript-lang/rescript-compiler/issues/5573 https://github.com/rescript-lang/rescript-compiler/pull/5589

:nail_care: Polish

• Several Belt / Js libraries are now converted to ReScript syntax, with corresponding comments in Markdown format suitable for hovering. See #5361.

Playground

:house: Internal

• Added jsoo_playground_main.ml as the rescript-lang.org playground bundle entrypoint

:boom: Breaking Change

• Removed Reason syntax support for the playground experience. See https://github.com/rescript-lang/rescript-compiler/pull/5375

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You can find more old changelog from docs/changelog