Migrate ESLint config to flat config and update deps

Replaces .eslintrc.js with eslint.config.js using the new flat config format. Updates ESLint and TypeScript ESLint dependencies to latest major versions, adjusts ignore patterns, and refactors htmlhint-server code to use unused parameter conventions. Also bumps VS Code engine and type dependencies for compatibility.

Author: coliff

.eslintrc.js

@@ -0,0 +1,110 @@
+const js = require("@eslint/js");
+const tseslint = require("@typescript-eslint/eslint-plugin");
+const tsparser = require("@typescript-eslint/parser");
+const prettier = require("eslint-config-prettier");
+
+module.exports = [
+  {
+    ignores: [
+      "test/**",
+      "**/*.d.ts",
+      "out/**",
+      "htmlhint/out/**",
+      "htmlhint-server/out/**",
+      ".vscode-test/**",
+      "node_modules/**",
+      "htmlhint/node_modules/**",
+      "htmlhint-server/node_modules/**",
+      "htmlhint/vscode-htmlhint-*.vsix",
+      "**/*.vsix",
+    ],
+  },
+  js.configs.recommended,
+  {
+    files: ["**/*.ts"],
+    languageOptions: {
+      parser: tsparser,
+      parserOptions: {
+        ecmaVersion: "latest",
+        sourceType: "module",
+      },
+      globals: {
+        console: "readonly",
+        process: "readonly",
+        Buffer: "readonly",
+        __dirname: "readonly",
+        __filename: "readonly",
+        global: "readonly",
+        module: "readonly",
+        require: "readonly",
+        exports: "readonly",
+        NodeJS: "readonly",
+      },
+    },
+    plugins: {
+      "@typescript-eslint": tseslint,
+    },
+    rules: {
+      ...tseslint.configs.recommended.rules,
+      "no-console": "error",
+      "no-empty": "off",
+      "no-var": "off",
+      "prefer-const": "off",
+      "@typescript-eslint/explicit-module-boundary-types": "off",
+      "@typescript-eslint/no-empty-interface": "off",
+      "@typescript-eslint/no-explicit-any": "off",
+      "@typescript-eslint/no-non-null-assertion": "off",
+      "@typescript-eslint/no-unused-vars": [
+        "error",
+        {
+          argsIgnorePattern: "^_",
+          varsIgnorePattern: "^_",
+          args: "after-used",
+        },
+      ],
+      "no-unused-vars": [
+        "error",
+        {
+          argsIgnorePattern: "^_",
+          varsIgnorePattern: "^_",
+          args: "after-used",
+        },
+      ],
+      "@typescript-eslint/no-var-requires": "off",
+    },
+  },
+  {
+    files: ["**/*.js"],
+    languageOptions: {
+      ecmaVersion: "latest",
+      sourceType: "commonjs",
+      globals: {
+        console: "readonly",
+        process: "readonly",
+        Buffer: "readonly",
+        __dirname: "readonly",
+        __filename: "readonly",
+        global: "readonly",
+        module: "readonly",
+        require: "readonly",
+        exports: "readonly",
+        NodeJS: "readonly",
+      },
+    },
+    rules: {
+      "no-console": "error",
+      "no-empty": "off",
+      "no-var": "off",
+      "prefer-const": "off",
+      "no-unused-vars": [
+        "error",
+        {
+          argsIgnorePattern: "^_",
+          varsIgnorePattern: "^_",
+          args: "after-used",
+        },
+      ],
+    },
+  },
+  prettier,
+];

eslint.config.js

@@ -67,7 +67,7 @@ interface HtmlHintConfig {
 
 let settings: Settings | null = null;
 let linter: {
-  verify: (text: string, config?: HtmlHintConfig) => htmlhint.Error[];
+  verify: (_text: string, _config?: HtmlHintConfig) => htmlhint.Error[];
 } | null = null;
 
 /**
@@ -82,9 +82,8 @@ let htmlhintrcOptions: Record<string, HtmlHintConfig | null | undefined> = {};
  */
 function makeDiagnostic(
   problem: htmlhint.Error,
-  document: TextDocument,
+  _document: TextDocument,
 ): Diagnostic {
-  const lines = document.getText().split("\n");
   const col = problem.col - 1;
   const endCol = problem.col + (problem.raw?.length || 0) - 1;
 
@@ -2190,16 +2189,7 @@ async function createAutoFixes(
 }
 
 connection.onInitialize(
-  (params: InitializeParams, token: CancellationToken) => {
-    let initOptions: {
-      nodePath: string;
-    } = params.initializationOptions;
-    let nodePath = initOptions
-      ? initOptions.nodePath
-        ? initOptions.nodePath
-        : undefined
-      : undefined;
-
+  (_params: InitializeParams, _token: CancellationToken) => {
     // Since Files API is no longer available, we'll use embedded htmlhint directly
     linter = (htmlhint.default ||
       htmlhint.HTMLHint ||
@@ -2281,7 +2271,6 @@ function doValidate(connection: Connection, document: TextDocument): void {
     }
 
     let contents = document.getText();
-    let lines = contents.split("\n");
 
     let config = getConfiguration(fsPath);
     trace(`[DEBUG] Loaded config: ${JSON.stringify(config)}`);

htmlhint-server/src/server.ts

@@ -26,7 +26,7 @@
     "Linters"
   ],
   "engines": {
-    "vscode": "^1.89.0"
+    "vscode": "^1.101.0"
   },
   "activationEvents": [
     "onLanguage:html",
@@ -91,8 +91,8 @@
     "package": "vsce package"
   },
   "devDependencies": {
-    "@types/node": "^22.15.31",
-    "@types/vscode": "^1.89.0",
+    "@types/node": "^22.19.1",
+    "@types/vscode": "^1.101.0",
     "@vscode/test-electron": "^2.5.2",
     "typescript": "5.5.4"
   },