TypeScript migration: src/ is now 100% TypeScript (Phases 0–6, #924)

.github/workflows/build.yml

@@ -33,6 +33,10 @@ jobs:
           cache-dependency-path: 'package-lock.json'
 
       - run: npm ci
+      - name: Type check
+        run: npm run type-check
+      - name: Golden tests (parser + export)
+        run: npm test
       - name: Build
         run: npm run build
         env:

eslint.config.ts

@@ -0,0 +1,81 @@
+import js from "@eslint/js";
+import tseslint from "typescript-eslint";
+import eslintConfigPrettier from "eslint-config-prettier";
+import globals from "globals";
+
+// Stylistic rules shared by JS and TS sources.
+const sharedRules = {
+  "no-var": "error",
+  "no-prototype-builtins": "error",
+  "no-empty": "error",
+  "no-inner-declarations": "error",
+  "no-fallthrough": "error",
+  "no-useless-escape": "error",
+  "no-constant-condition": "error",
+  "no-unreachable": "error",
+  "no-duplicate-case": "error",
+  "no-dupe-keys": "error",
+  "no-irregular-whitespace": "error",
+  "no-case-declarations": "error",
+  eqeqeq: ["error", "smart"],
+  "prefer-const": "error",
+  "prefer-template": "error",
+  radix: "error",
+  "comma-dangle": ["error", "always-multiline"],
+  semi: ["error", "always"],
+};
+
+export default [
+  {
+    ignores: ["src/vendor/", "dist/", "public/", "test/"],
+  },
+  js.configs.recommended,
+  // typescript-eslint scoped to TS sources only — JS keeps the core ruleset below.
+  ...tseslint.config({
+    files: ["src/**/*.ts"],
+    extends: [tseslint.configs.recommended],
+  }),
+  eslintConfigPrettier,
+  {
+    files: ["src/**/*.js"],
+    languageOptions: {
+      ecmaVersion: "latest",
+      sourceType: "module",
+      globals: {
+        ...globals.browser,
+        THREE: "readonly", // vendored three.min.js (r70, loaded via <script>)
+        L: "readonly", // Leaflet (loaded via <script>)
+        chrome: "readonly", // Chrome/Electron extension APIs (pref_storage.js)
+        __APP_VERSION__: "readonly", // Vite define
+      },
+    },
+    rules: {
+      ...sharedRules,
+      "no-undef": "error",
+      "no-redeclare": "error",
+      "no-unused-vars": [
+        "error",
+        { argsIgnorePattern: "^_", varsIgnorePattern: "^_" },
+      ],
+    },
+  },
+  {
+    files: ["src/**/*.ts"],
+    languageOptions: {
+      ecmaVersion: "latest",
+      sourceType: "module",
+      globals: {
+        ...globals.browser,
+      },
+    },
+    rules: {
+      ...sharedRules,
+      // TypeScript's own checker handles undefined references and redeclarations.
+      "no-undef": "off",
+      "@typescript-eslint/no-unused-vars": [
+        "error",
+        { argsIgnorePattern: "^_", varsIgnorePattern: "^_" },
+      ],
+    },
+  },
+];