1 files changed, 145 insertions, 0 deletions
diff --git a/eslint.config.js b/eslint.config.js
new file mode 100644
index 00000000..77c02f36
--- /dev/null
+++ b/eslint.config.js
@@ -0,0 +1,145 @@
+import path from 'node:path';
+import {fileURLToPath} from 'node:url';
+
+import {defineConfig} from 'eslint/config';
+import {FlatCompat} from '@eslint/eslintrc';
+import js from '@eslint/js';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all,
+});
+
+const CLIENT_JAVASCRIPT_PATHS = [
+  'src/static/js/**/*.js',
+];
+
+const WEB_WORKER_PATHS = [
+  'src/static/js/search-worker.js',
+];
+
+const COMMON_GLOBALS = {
+  supportedWhenever: {
+    URL: 'readonly',
+
+    clearInterval: 'readonly',
+    clearTimeout: 'readonly',
+    console: 'readonly',
+    fetch: 'readonly',
+    setInterval: 'readonly',
+    setTimeout: 'readonly',
+    structuredClone: 'readonly',
+  },
+};
+
+export default defineConfig([
+  // basic config
+
+  {
+    files: ['src/**/*.js'],
+    extends: compat.extends('eslint:recommended'),
+
+    rules: {
+      indent: ['off'],
+
+      'no-empty': ['error', {
+        allowEmptyCatch: true,
+      }],
+
+      'no-unexpected-multiline': ['off'],
+      'no-unused-labels': ['off'],
+
+      'no-unused-vars': ['error', {
+        argsIgnorePattern: '^_',
+        destructuredArrayIgnorePattern: '^',
+      }],
+
+      'no-cond-assign': ['off'],
+      'no-constant-condition': ['off'],
+      'no-unsafe-finally': ['off'],
+      'no-self-assign': ['off'],
+      'require-yield': ['off'],
+    },
+  },
+
+  // node.js
+
+  {
+    files: ['src/**/*.js'],
+    ignores: [...CLIENT_JAVASCRIPT_PATHS],
+
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: 'module',
+
+      globals: {
+        ...COMMON_GLOBALS.supportedWhenever,
+
+        process: 'readonly',
+        setImmediate: 'readonly',
+      },
+    },
+  },
+
+  // client javascript - all
+
+  {
+    files: [...CLIENT_JAVASCRIPT_PATHS],
+
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: 'module',
+
+      globals: {
+        ...COMMON_GLOBALS.supportedWhenever,
+
+        CustomEvent: 'readonly',
+        Response: 'readonly',
+        Worker: 'readonly',
+        XMLHttpRequest: 'readonly',
+      },
+    },
+  },
+
+  // client javascript - not web workers
+
+  {
+    files: [...CLIENT_JAVASCRIPT_PATHS],
+    ignores: [...WEB_WORKER_PATHS],
+
+    languageOptions: {
+      globals: {
+        DOMException: 'readonly',
+        DOMRect: 'readonly',
+        MutationObserver: 'readonly',
+        IntersectionObserver: 'readonly',
+
+        document: 'readonly',
+        getComputedStyle: 'readonly',
+        history: 'readonly',
+        location: 'readonly',
+        localStorage: 'readonly',
+        sessionStorage: 'readonly',
+        window: 'readonly',
+      },
+    },
+  },
+
+  // client javascript - web workers
+
+  {
+    files: [WEB_WORKER_PATHS],
+
+    languageOptions: {
+      globals: {
+        onerror: 'writeable',
+        onmessage: 'writeable',
+        onunhandledrejection: 'writeable',
+        postMessage: 'readonly',
+      },
+    },
+  },
+]);