Add parserOptions for Svelte + TypeScript

configs/svelte.js

@@ -2,6 +2,14 @@
 
 const generic = require('./generic.js');
 
+let typescriptInstalled = true;
+
+try {
+  require('typescript');
+  typescriptInstalled = true;
+}
+catch { /* not installed */ }
+
 /**
  * An extension on the default yeslint! generic config, with rules specific to
  * Svelte codebases and JavaScript source code for browser environments.
@@ -12,6 +20,7 @@ const generic = require('./generic.js');
  * @type {import('eslint').Linter.Config}
  */
 const svelte = {
+  ...generic,
   parserOptions: {
     ...generic.parserOptions,
     ecmaVersion: 2020,
@@ -31,18 +40,16 @@ const svelte = {
     ...generic.plugins,
     'svelte',
   ],
-  overrides: [ {
+  overrides: [
+    ...generic.overrides,
+    {
       files: '*.svelte',
       parser: 'svelte-eslint-parser',
+      parserOptions: typescriptInstalled ? {
+        parser: '@typescript-eslint/parser',
+      } : undefined,
       rules: {
         'no-inner-declarations': 0,
-      'max-len': [
-        'warn',
-        {
-          ...generic.rules['max-len'][1],
-          code: 200,
-        },
-      ],
         'svelte/no-inner-declarations': [
           'error',
           'functions',
@@ -97,7 +104,8 @@ const svelte = {
           'all',
         ],
       },
-  }  ],
+    },
+  ],
   rules: {
     ...generic.rules,
     strict: 0,