Oxlint Setup

Be sure to have installed both Oxlint and the Effect TypeScript-Go integration. The following commands will install the latest versions of both:

pnpm add --save-dev @effect/tsgo oxlint oxlint-tsgolint

Update the scripts section of your package.json to include the following:

{
  "scripts": {
    "prepare": "effect-tsgo patch --oxlint",
  }
}

This will patch Oxlint to use the Effect TypeScript-Go integration after any package installation. To avoid patching TypeScript, you can use the --no-typescript flag: effect-tsgo patch --no-typescript --oxlint. This will patch Oxlint to use the Effect TypeScript-Go integration without patching TypeScript.

LSP diagnostics

When you have the Effect LSP enabled as well, we recommend setting diagnostics to false in the LSP plugin settings so that Effect diagnostics are reported only by Oxlint and do not appear twice:

{
  "compilerOptions": {
    "plugins": [
      {
        "name": "@effect/language-service",
        "diagnostics": false
      }
    ]
  }
}

Run pnpm install to install the dependencies and run the prepare script to patch Oxlint.

pnpm install

Effect rules require Oxlint's type-aware mode and the effecttsgo plugin. The recommended preset enables both and configures the recommended Effect rules. Use the schema shipped with @effect/tsgo for validation and completions:

{
  "$schema": "./node_modules/@effect/tsgo/oxlint-schema.json",
  "extends": [
    "./node_modules/@effect/tsgo/oxlint-presets/recommended.json"
  ]
}

The package also provides presets for each diagnostic category: correctness, antipattern, effect-native, and style. Extended configurations are applied in order, and rules in the project configuration take precedence, so categories can be combined and individual rules can be adjusted:

{
  "$schema": "./node_modules/@effect/tsgo/oxlint-schema.json",
  "extends": [
    "./node_modules/@effect/tsgo/oxlint-presets/correctness.json",
    "./node_modules/@effect/tsgo/oxlint-presets/effect-native.json"
  ],
  "rules": {
    "effecttsgo/global-date": "error",
    "effecttsgo/global-console": "off"
  }
}

With oxlint.config.ts, import the same configurations from the package:

import { recommended } from "@effect/tsgo/oxlint-presets"
import { defineConfig } from "oxlint"

export default defineConfig({
  extends: [recommended]
})

You can then run Oxlint normally:

pnpm exec oxlint .

The installed oxlint and oxlint-tsgolint versions must match the versions supported by the installed @effect/tsgo release. The patch command validates this before changing either integration.

Use the same integration flags when restoring binaries:

pnpm exec effect-tsgo unpatch --oxlint
pnpm exec effect-tsgo unpatch --no-typescript --oxlint

Known limitations

• All rules require Oxlint's type-aware mode, because they rely on type information to provide accurate diagnostics.