build: replace ESLint and Prettier with Biome

.github/workflows/checks.yml

@@ -56,7 +56,7 @@ jobs:
         run: pnpm install --frozen-lockfile
 
       - name: Lint
-        run: pnpm lint
+        run: pnpm exec biome ci .
 
   test:
     needs: prep

README.md

@@ -544,12 +544,18 @@ Run tests
 pnpm test
 ```
 
-Lint
+Lint and check formatting ([Biome](https://biomejs.dev))
 
 ```sh
 pnpm lint
 ```
 
+Format
+
+```sh
+pnpm format
+```
+
 Build
 
 ```sh

biome.jsonc

@@ -0,0 +1,77 @@
+{
+  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
+  "vcs": { "enabled": true, "clientKind": "git", "useIgnoreFile": true },
+  "files": {
+    "includes": ["**", "!!**/dist", "!!**/build", "!!**/coverage"]
+  },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "space",
+    "indentWidth": 2,
+    "lineWidth": 100
+  },
+  "javascript": {
+    // tsconfig.json uses `"jsx": "react"`, so React must stay a value import.
+    "jsxRuntime": "reactClassic",
+    "formatter": {
+      "quoteStyle": "single",
+      "trailingCommas": "es5",
+      "semicolons": "always"
+    }
+  },
+  "assist": {
+    "actions": { "source": { "organizeImports": "off" } }
+  },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "preset": "recommended",
+      "correctness": {
+        // Enforce the rules of hooks, e.g. no conditional hook calls.
+        "useHookAtTopLevel": "error",
+        // Unused parameters must be prefixed with `_`.
+        "noUnusedFunctionParameters": "error"
+      },
+      "suspicious": {
+        // Helps with cleaning debug statements by erroring on console.
+        "noConsole": "error",
+        // Array indexes as keys should not be used. The occasional time it is
+        // needed, an ignore can be added.
+        "noArrayIndexKey": "error",
+        // TODO: Consider making this an error in the future.
+        "noExplicitAny": "warn"
+      },
+      "style": {
+        // Force self closing components when there are no children.
+        // Prevents `<MyComp prop='1'></MyComp>`
+        "useSelfClosingElements": "error"
+      },
+      "nursery": {
+        // Type-aware promise checks, replacing the equivalent
+        // typescript-eslint type-checked rules.
+        "noFloatingPromises": "error",
+        "noMisusedPromises": "error",
+        // Off: Biome's type inference does not resolve overloads like
+        // `act(async () => {})` and reports them as non-thenables.
+        "useAwaitThenable": "off"
+      }
+    }
+  },
+  "overrides": [
+    {
+      // The example app is due to be rebuilt; keep its lint scope to what
+      // ESLint enforced before.
+      "includes": ["example/**"],
+      "linter": {
+        "rules": {
+          "a11y": "off",
+          "suspicious": {
+            "noShadowRestrictedNames": "off",
+            // Tailwind v3 directives
+            "noUnknownAtRules": { "level": "error", "options": { "ignore": ["tailwind"] } }
+          }
+        }
+      }
+    }
+  ]
+}

example/src/App.jsx

@@ -27,7 +27,7 @@ function App() {
 
   // Debug: Verify QueryClient configuration
   if (isDevelopment && typeof window !== 'undefined') {
-    // eslint-disable-next-line no-console
+    // biome-ignore lint/suspicious/noConsole: debug output in the example app
     console.log('[App] QueryClient defaults:', queryClient.getDefaultOptions());
   }
 

example/src/pages/Main/ItemDetails.jsx

@@ -4,9 +4,7 @@ import { H2 } from '../../components/headers';
 import Panel from '../../layout/Panel';
 import { Button } from '../../components/buttons';
 
-// eslint-disable-next-line react/prop-types
 function ItemDetails({ item, onClose }) {
-  // eslint-disable-next-line react/prop-types
   const itemUrl = item.links.find((r) => r.rel === 'self')?.href;
   const { item: newItem, isLoading, error, reload } = useItem(itemUrl);
 

example/src/pages/Main/index.jsx

@@ -1,16 +1,16 @@
 import { useCallback, useState } from 'react';
-// eslint-disable-next-line no-unused-vars
+// biome-ignore lint/correctness/noUnusedImports: kept for reference in the example
 import { useStacSearch, useCollections, useStacApi, StacApiProvider } from 'stac-react';
 
 import ItemList from './ItemList';
 import Map from './Map';
 import QueryBuilder from './QueryBuilder';
 import ItemDetails from './ItemDetails';
 
-// eslint-disable-next-line no-unused-vars
+// biome-ignore lint/correctness/noUnusedVariables: kept for reference in the example
 const options = {
   headers: {
     Authorization: 'Basic ' + btoa(process.env.REACT_APP_STAC_API_TOKEN + ':'),
   },
 };
 

example/src/reportWebVitals.js

@@ -1,6 +1,6 @@
 const reportWebVitals = (onPerfEntry) => {
   if (onPerfEntry && onPerfEntry instanceof Function) {
-    import('web-vitals').then(({ getCLS, getFID, getFCP, getLCP, getTTFB }) => {
+    void import('web-vitals').then(({ getCLS, getFID, getFCP, getLCP, getTTFB }) => {
       getCLS(onPerfEntry);
       getFID(onPerfEntry);
       getFCP(onPerfEntry);

package.json

@@ -20,7 +20,7 @@
     "stac-ts": "^1"
   },
   "devDependencies": {
-    "@eslint/js": "^9.39.4",
+    "@biomejs/biome": "2.5.14",
     "@tanstack/react-query": "^5.104.0",
     "@testing-library/dom": "^10.4.2",
     "@testing-library/jest-dom": "^7.0.1",
@@ -30,28 +30,20 @@
     "@types/node": "^24.19.0",
     "@types/react": "^19.3.0",
     "@types/react-dom": "^19.3.0",
-    "eslint": "^9.39.5",
-    "eslint-config-prettier": "^10.1.8",
-    "eslint-plugin-prettier": "^5.5.6",
-    "eslint-plugin-react": "^7.37.5",
-    "eslint-plugin-react-hooks": "^7.1.1",
-    "eslint-plugin-react-refresh": "^0.5.7",
-    "globals": "^17.12.0",
     "jest": "^30.5.2",
     "jest-environment-jsdom": "^30.5.2",
     "jest-fetch-mock": "^4.2.0",
-    "prettier": "^3.9.9",
     "react": "^19.3.0",
     "react-dom": "^19.3.0",
     "stac-ts": "^1.0.5",
     "ts-jest": "^29.4.14",
     "typescript": "~6.0",
-    "typescript-eslint": "^8.71.0",
     "vite": "^8.3.1",
     "vite-plugin-dts": "^5.1.1"
   },
   "scripts": {
-    "lint": "eslint .",
+    "lint": "biome check .",
+    "format": "biome format --write .",
     "test": "jest",
     "build": "tsc -b && vite build",
     "prepublishOnly": "rm -rf dist && pnpm build"