refactor: update eslint to 9

.vscode/settings.json

@@ -0,0 +1,12 @@
+{
+    "eslint.experimental.useFlatConfig": true,
+    "cSpell.ignorePaths": [
+        "package-lock.json",
+        "node_modules",
+        "vscode-extension",
+        ".git/objects",
+        ".vscode",
+        ".vscode-insiders",
+        "**/*.js"
+    ]
+}

eslint.config.mjs

@@ -0,0 +1,40 @@
+import js from '@eslint/js';
+import globals from 'globals';
+import stylisticJs from '@stylistic/eslint-plugin-js';
+
+export default [
+    js.configs.recommended,
+    {
+        languageOptions: {
+            globals: {
+                ...globals.browser
+            }
+        },
+        plugins: {
+            '@stylistic/js': stylisticJs
+        },
+        rules: {
+            '@stylistic/js/indent': [
+                'error',
+                4,
+                { SwitchCase: 1 }
+            ],
+            '@stylistic/js/linebreak-style': [
+                'error',
+                'unix'
+            ],
+            '@stylistic/js/quotes': [
+                'error',
+                'single',
+                { allowTemplateLiterals: true }
+            ],
+            '@stylistic/js/semi': [
+                'error',
+                'always'
+            ],
+            '@stylistic/js/no-trailing-spaces': ['error', { skipBlankLines: true }],
+            camelcase: ['off'],
+            'prefer-const': ['error'],
+        }
+    }
+];