Migrate ESLint to use new flat config (Fixes mozmeao#42) (mozmeao#43)

CHANGELOG.md

@@ -1,6 +1,7 @@
 # HEAD
 
-- **js:** Migrate JS tests to jasmine-browser-runner (#40).
+-   **js:** Migrate ESLint to use new flat config (#42).
+-   **js:** Migrate JS tests to jasmine-browser-runner (#40).
 
 # 2.0.1
 

eslint.config.js

@@ -0,0 +1,94 @@
+const js = require('@eslint/js');
+const globals = require('globals');
+const eslintConfigPrettier = require('eslint-config-prettier');
+
+const rules = {
+    // Use type-safe equality operators
+    // https://eslint.org/docs/rules/eqeqeq
+    eqeqeq: ['error', 'always'],
+
+    // Treat var statements as if they were block scoped
+    // https://eslint.org/docs/rules/block-scoped-var
+    'block-scoped-var': 'error',
+
+    // Disallow Use of alert, confirm, prompt
+    // https://eslint.org/docs/rules/no-alert
+    'no-alert': 'error',
+
+    // Disallow eval()
+    // https://eslint.org/docs/rules/no-eval
+    'no-eval': 'error',
+
+    // Disallow empty functions
+    // https://eslint.org/docs/rules/no-empty-function
+    'no-empty-function': 'error',
+
+    // Require radix parameter
+    // https://eslint.org/docs/rules/radix
+    radix: 'error',
+
+    // Disallow the use of `console`
+    // https://eslint.org/docs/rules/no-console
+    'no-console': 'error'
+};
+
+module.exports = [
+    js.configs.recommended,
+    eslintConfigPrettier,
+    {
+        ignores: ['dist/**/*.js', 'demo/libs/**/*.js', 'tests/dist/**/*.js']
+    },
+    {
+        files: ['src/**/*.js'],
+        languageOptions: {
+            ecmaVersion: 2017,
+            globals: {
+                Mozilla: true,
+                ...globals.browser,
+                ...globals.commonjs
+            }
+        },
+        rules: rules
+    },
+    {
+        files: ['demo/**/*.js'],
+        languageOptions: {
+            ecmaVersion: 'latest',
+            globals: {
+                Mozilla: true,
+                ...globals.browser,
+                ...globals.node,
+                ...globals.commonjs
+            }
+        },
+        rules: rules
+    },
+    {
+        files: ['tests/**/*.js'],
+        languageOptions: {
+            ecmaVersion: 'latest',
+            sourceType: 'module',
+            globals: {
+                Mozilla: true,
+                ...globals.browser,
+                ...globals.jasmine
+            }
+        },
+        rules: rules
+    },
+    {
+        files: [
+            'webpack.config.js',
+            'webpack.test.config.js',
+            'eslint.config.js'
+        ],
+        languageOptions: {
+            ecmaVersion: 'latest',
+            globals: {
+                ...globals.node,
+                ...globals.commonjs
+            }
+        },
+        rules: rules
+    }
+];