chore: Update to eslint 9, fix found issues

config/rollup.node-config.mjs

@@ -1,4 +1,3 @@
-import { chmod, stat } from 'node:fs/promises'
 import typescript from '@rollup/plugin-typescript'
 
 export default [

eslint.config.mjs

@@ -0,0 +1,68 @@
+import eslint from '@eslint/js'
+import prettierConfig from 'eslint-config-prettier'
+import typescript from 'typescript-eslint'
+
+export default [
+  {
+    ignores: [
+      'browser/',
+      'dist/',
+      'docs/',
+      'docs-slate/',
+      'lib/',
+      'package-lock.json',
+      'playground/dist/',
+      'tests/artifacts/',
+      'tests/json-test-suite/',
+      'tests/yaml-test-suite/'
+    ]
+  },
+  eslint.configs.recommended,
+  ...typescript.configs.recommended,
+  prettierConfig,
+  {
+    languageOptions: {
+      parserOptions: {
+        projectService: {
+          allowDefaultProject: ['*js', 'config/*js'],
+          defaultProject: 'tsconfig.json'
+        }
+      }
+    },
+
+    rules: {
+      'array-callback-return': 'error',
+      camelcase: 'error',
+      eqeqeq: ['error', 'always', { null: 'ignore' }],
+      'no-constant-condition': ['error', { checkLoops: false }],
+      'no-control-regex': 'off',
+      'no-fallthrough': ['error', { commentPattern: 'fallthrough' }],
+      'no-implicit-globals': 'error',
+      'no-template-curly-in-string': 'warn',
+      'no-var': 'error',
+      'prefer-const': ['warn', { destructuring: 'all' }],
+      '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-namespace': 'off',
+      '@typescript-eslint/no-unused-vars': [
+        'warn',
+        { argsIgnorePattern: '^_' }
+      ],
+      '@typescript-eslint/prefer-includes': 'warn',
+      '@typescript-eslint/prefer-nullish-coalescing': [
+        'warn',
+        { ignoreMixedLogicalExpressions: true }
+      ],
+      '@typescript-eslint/prefer-optional-chain': 'warn'
+    }
+  },
+
+  {
+    files: ['config/**'],
+    languageOptions: { globals: { console: true, module: true, process: true } }
+  },
+
+  {
+    files: ['tests/**'],
+    rules: { camelcase: 0 }
+  }
+]