options.md

October 24, 2015 · View on GitHub

Usage

babel.transform(code, options);

$ babel --name=value

Options

Option	Default	Description
`filename`	`"unknown"`	Filename for use in errors etc.
`filenameRelative`	`(filename)`	Filename relative to `sourceRoot`.
`blacklist`	`[]`	Array of transformers to exclude. Run `babel --help` to see a full list of transformers.
`whitelist`	`[]`	Array of transformers to only use. Run `babel --help` to see a full list of transformers.
`loose`	`[]`	Array of transformers to enable loose mode on.
`optional`	`[]`	Array of transformers to optionally use. Run `babel --help` to see a full list of transformers. Optional transformers displayed inside square brackets.
`nonStandard`	`true`	Enable support for JSX and Flow.
`highlightCode`	`true`	ANSI highlight syntax error code frames
`only`	`null`	A glob, regex, or mixed array of both, matching paths to only compile. Can also be an array of arrays containing paths to explicitly match. When attempting to compile a non-matching file it's returned verbatim.
`ignore`	`null`	Opposite to the `only` option.
`jsxPragma`	`null`	Custom pragma to use for JSX elements
`auxiliaryCommentBefore`	`null`	Attach a comment before all helper declarations and auxiliary code. eg. `"istanbul ignore next"`
`sourceMaps`	`false`	If truthy, adds a `map` property to returned output. If set to `"inline"`, a comment with a sourceMappingURL directive is added to the bottom of the returned code. If set to `"both"` then a `map` property is returned as well as a source map comment appended.
`inputSourceMap`	`null`	A source map object that the output source map will be based on.
`sourceMapTarget`	`(filenameRelative)`	Set `file` on returned source map.
`sourceFileName`	`(filenameRelative)`	Set `sources[0]` on returned source map.
`sourceRoot`	`(moduleRoot)`	The root from which all sources are relative.
`moduleRoot`	`(sourceRoot)`	Optional prefix for the AMD module formatter that will be prepend to the filename on module definitions.
`modules`	`"common"`	Which module formatter to use. Run `babel --help` to see a full list of module formatters.
`moduleIds`	`false`	If truthy, insert an explicit id for modules. By default, all modules are anonymous. (Not available for `common` modules)
`moduleId`	`null`	Specify a custom name for module ids.
`getModuleId`	`null`	Specify a custom callback to generate a module id with. Called as `getModuleId(moduleName)`. If falsy value is returned then the generated module id is used.
`resolveModuleSource`	`null`	Resolve a module source ie. `import "SOURCE";` to a custom value. Called as `resolveModuleSource(source, filename)`.
`keepModuleIdExtensions`	`false`	Keep extensions in module ids
`externalHelpers`	`false`	Uses a reference to `babelHelpers` instead of placing helpers at the top of your code. Meant to be used in conjunction with external helpers.
`code`	`true`	Enable code generation
`ast`	`true`	Include the AST in the returned object
`stage`	`2`	Set the experimental proposal stage.
`compact`	`"auto"`	Do not include superfluous whitespace characters and line terminators. When set to `"auto"` compact is set to `true` on input sizes of >100KB.
`comments`	`true`	Output comments in generated output.
`shouldPrintComment`	null	An optional callback that controls whether a comment should be output or not. Called as `shouldPrintComment(commentContents)`. NOTE: This overrides the `comment` option when used.
`metadataUsedHelpers`	`false`	See external helpers - selective builds for more information.
`env`	`{}`	This is an object of keys that represent different environments. For example, you may have: { env: { production: { /* specific options */ } } }` which will use those options when the enviroment variable `BABEL_ENV` is set to `"production"`. If `BABEL_ENV` isn't set then `NODE_ENV` will be used, if it's not set then it defaults to `"development"`
`retainLines`	`false`	Retain line numbers. This will lead to wacky code but is handy for scenarios where you can't use source maps. NOTE: This will obviously not retain the columns.
`babelrc`	`null`	Specify a custom file path to load a `.babelrc` config from.