chore(ci): eslint + prettier → biome (#325)

Author: sampotts

.github/scripts/label-issue.js

@@ -1,7 +1,6 @@
 import core from '@actions/core';
 import github from '@actions/github';
 
-// eslint-disable-next-line node/prefer-global/process
 const GH_TOKEN = process.env.GITHUB_TOKEN;
 
 const pkgLabel = {
@@ -77,7 +76,6 @@ async function run() {
 
     console.log(`Matched labels: ${Array.from(labels).join(', ')}`);
 
-    // eslint-disable-next-line node/prefer-global/process
     if (process.env.DRY_RUN === 'true') {
       console.log('⚠️ DRY RUN: Skipping API call.');
       return;

.prettierignore

@@ -1,6 +1,6 @@
 {
   "recommendations": [
-    "dbaeumer.vscode-eslint",
+    "biomejs.biome",
     "hyrious.import-cost",
     "streetsidesoftware.code-spell-checker",
     "DavidAnson.vscode-markdownlint",

.prettierrc.cjs

@@ -1,55 +1,19 @@
 {
-  // At some point, we'll watch to flick this on and uncomment lines 5 & 6 below.
-  "eslint.enable": true,
-  // Disable the default formatter, use eslint instead
+  // We use Biome for linting and formatting.
+  "eslint.enable": false,
   "prettier.enable": false,
-  "editor.formatOnSave": false,
+  "editor.formatOnSave": true,
 
   // Auto fix
   "editor.codeActionsOnSave": {
-    "source.fixAll.eslint": "explicit",
+    // Auto fix all Biome issues on save.
+    "source.fixAll.biome": "always",
+    "source.organizeImports.biome": "always",
+    // Disable built-in organize imports to avoid conflicts with Biome.
     "source.organizeImports": "never"
   },
 
-  // Silent the stylistic rules in you IDE, but still auto fix them
-  "eslint.rules.customizations": [
-    { "rule": "style/*", "severity": "off", "fixable": true },
-    { "rule": "format/*", "severity": "off", "fixable": true },
-    { "rule": "*-indent", "severity": "off", "fixable": true },
-    { "rule": "*-spacing", "severity": "off", "fixable": true },
-    { "rule": "*-spaces", "severity": "off", "fixable": true },
-    { "rule": "*-order", "severity": "off", "fixable": true },
-    { "rule": "*-dangle", "severity": "off", "fixable": true },
-    { "rule": "*-newline", "severity": "off", "fixable": true },
-    { "rule": "*quotes", "severity": "off", "fixable": true },
-    { "rule": "*semi", "severity": "off", "fixable": true }
-  ],
-
-  // Enable eslint for all supported languages
-  "eslint.validate": [
-    "javascript",
-    "javascriptreact",
-    "typescript",
-    "typescriptreact",
-    "vue",
-    "html",
-    "markdown",
-    "json",
-    "jsonc",
-    "yaml",
-    "toml",
-    "xml",
-    "gql",
-    "graphql",
-    "astro",
-    "svelte",
-    "css",
-    "less",
-    "scss",
-    "pcss",
-    "postcss",
-    "svg"
-  ],
-  "editor.defaultFormatter": "dbaeumer.vscode-eslint",
+  "biome.requireConfiguration": true,
+  "editor.defaultFormatter": "biomejs.biome",
   "typescript.tsdk": "node_modules/typescript/lib"
 }

.vscode/extensions.json

@@ -157,9 +157,9 @@ When generating or editing code in this repository, follow these rules to ensure
    - Preserve comments, type signatures, and existing code style.
 
 2. **Match Existing Conventions**
-   - Follow the repo’s Prettier, ESLint, and TypeScript settings automatically.
+   - Follow the repo's Biome and TypeScript settings automatically.
    - Use consistent naming (camelCase for variables, PascalCase for components).
-   - Prefer imports ordered and sorted as per `@antfu/eslint-config`.
+   - Biome handles import organization (side-effects → external → internal).
 
 3. **Type Safety First**
    - Never remove or bypass TypeScript types.

.vscode/settings.json

@@ -97,7 +97,7 @@ pnpm build
 
 ### 🧹 Style & Linting
 
-For the bulk of our core code, we use a [slightly modified](./eslint.config.mjs) version of [`@antfu/eslint-config`](https://www.npmjs.com/package/@antfu/eslint-config) along with [`prettier`](https://prettier.io/) for things like markdown or svgs. Between IDE configs, pre-commit hooks, and manual CLI fixes, many styling and linting issues should get caught automatically.
+For the bulk of our core code, we use [Biome](https://biomejs.dev). Between IDE configs, pre-commit hooks, and manual CLI fixes, many styling and linting issues should get caught automatically.
 
 To ensure your code follows our lint rules with:
 

CLAUDE.md

@@ -0,0 +1,84 @@
+{
+  "$schema": "https://biomejs.dev/schemas/2.3.11/schema.json",
+  "html": {
+    "experimentalFullSupportEnabled": false
+  },
+  "assist": { "actions": { "source": { "organizeImports": "on" } } },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "space",
+    "indentWidth": 2,
+    "lineWidth": 120
+  },
+  "javascript": {
+    "formatter": {
+      "quoteStyle": "single",
+      "semicolons": "always",
+      "trailingCommas": "es5",
+      "bracketSpacing": true,
+      "arrowParentheses": "always"
+    }
+  },
+  "json": {
+    "formatter": {
+      "indentWidth": 2
+    }
+  },
+  "css": {
+    "parser": {
+      "tailwindDirectives": true
+    }
+  },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "recommended": true,
+      "style": {
+        "noNamespace": "off",
+        "noNonNullAssertion": "off"
+      },
+      "suspicious": {
+        "noExplicitAny": "off",
+        "noConfusingVoidType": "off",
+        "useIterableCallbackReturn": "off",
+        "noAssignInExpressions": "off",
+        "noDocumentCookie": "off",
+        "noThenProperty": "off"
+      },
+      "security": {
+        "noDangerouslySetInnerHtml": "off"
+      },
+      "complexity": {
+        "noUselessFragments": "warn",
+        "noArguments": "off"
+      },
+      "correctness": {
+        "noUnusedVariables": "warn",
+        "noUnusedImports": "warn",
+        "noUnusedFunctionParameters": "off",
+        "useExhaustiveDependencies": "warn"
+      },
+      "a11y": {
+        "noSvgWithoutTitle": "warn"
+      }
+    }
+  },
+  "files": {
+    "includes": [
+      "**",
+      "!**/CLAUDE.md",
+      "!**/.claude",
+      "!**/.astro",
+      "!**/.vercel",
+      "!**/.turbo",
+      "!**/.next",
+      "!**/.github",
+      "!**/dist",
+      "!**/styles/vjs.css",
+      "!**/packages/__tech-preview__",
+      "!**/examples",
+      "!**/*.astro",
+      "!**/packages/react/src/icons/generated-icons"
+    ]
+  }
+}

CONTRIBUTING.md

@@ -5,7 +5,7 @@ export default {
     /** @param {string} message */
     (message) => {
       const lower = message.toLowerCase().trim();
-      return ['wip'].some(word => lower.startsWith(word));
+      return ['wip'].some((word) => lower.startsWith(word));
     },
   ],
   rules: {

biome.json

@@ -1,24 +1,17 @@
 {
   "version": "0.2",
-  "ignorePaths": [
-    "package.json",
-    "tsconfig.json"
-  ],
+  "ignorePaths": ["package.json", "tsconfig.json"],
   "dictionaryDefinitions": [],
-  "dictionaries": [
-    "css",
-    "html",
-    "node",
-    "typescript",
-    "npm"
-  ],
+  "dictionaries": ["css", "html", "node", "typescript", "npm"],
   "words": [
     "antfu",
     "demuxed",
+    "nanostores",
     "noautohide",
     "noto",
     "nums",
     "plyr",
+    "prefs",
     "rahim",
     "segoe",
     "shiki",