Set up eslint with type information

gdn-app/eslint.config.js

@@ -1,3 +1,5 @@
+// @ts-check
+
 // https://eslint.org/docs/latest/use/configure/
 // https://eslint.vuejs.org/user-guide/
 
@@ -7,15 +9,29 @@ import pluginVue from "eslint-plugin-vue";
 import configPrettier from "eslint-config-prettier";
 
 export default tseslint.config(
-  { ignores: ["dist/", "src/vite-env.d.ts"] },
+  { ignores: ["dist/", "eslint.config.js", "vite.config.ts", "src/vite-env.d.ts"] },
+
   eslint.configs.recommended,
-  ...tseslint.configs.recommended,
-  ...tseslint.configs.stylistic,
+  ...tseslint.configs.strictTypeChecked,
+  ...tseslint.configs.stylisticTypeChecked,
   ...pluginVue.configs["flat/recommended"],
 
-  // We don't want prettier's formatting decisions being second-guessed by eslint.
+  // Prettier's formatting decisions should not be second-guessed by eslint.
   configPrettier,
 
-  // We need to tell the vue parser that it should use the ts parser instead of the js parser.
+  // Set up the ts parser to use type info and understand vue files.
+  {
+    languageOptions: {
+      parserOptions: {
+        projectService: true,
+        tsconfigRootDir: import.meta.dirname,
+
+        // Otherwise the parser will complain that it doesn't know vue files.
+        extraFileExtensions: ["vue"],
+      },
+    },
+  },
+
+  // Tell the vue parser that it should use the ts parser instead of the js parser.
   { files: ["**/*.vue"], languageOptions: { parserOptions: { parser: tseslint.parser } } },
 );