Convert ESLint config to flat config format (#21)

Author: Copilot

.eslintrc

@@ -0,0 +1,159 @@
+const globals = require( 'globals' );
+const js = require( '@eslint/js' );
+
+module.exports = [
+  js.configs.recommended,
+  {
+    languageOptions: {
+      sourceType: 'commonjs',
+      ecmaVersion: 2021,
+      globals: {
+        ...globals.node,
+        arguments: 'writable',
+      },
+    },
+
+    rules: {
+      'array-bracket-spacing': ['error', 'never'],
+      'brace-style': ['error', 'stroustrup', {
+        allowSingleLine: true,
+      }],
+      'camelcase': ['error', {
+        properties: 'never',
+      }],
+      'comma-spacing': ['error', {
+        before: false,
+        after: true,
+      }],
+      'comma-style': ['error', 'last'],
+      'comma-dangle': ['error', 'always-multiline'],
+      'complexity': ['warn', 8],
+      'computed-property-spacing': ['error', 'never'],
+      'consistent-return': 'warn',
+      'curly': ['error', 'all'],
+      'default-case': 'error',
+      'dot-notation': ['warn', {
+        allowKeywords: true,
+      }],
+      'dot-location': ['error', 'property'],
+      'eol-last': 'error',
+      'eqeqeq': 'error',
+      'func-style': 'off',
+      'guard-for-in': 'off',
+      'indent': ['error', 2, {
+        SwitchCase: 1,
+      }],
+      'keyword-spacing': 'error',
+      'key-spacing': ['error', {
+        beforeColon: false,
+        afterColon: true,
+      }],
+      'lines-around-comment': ['error', {
+        beforeBlockComment: true,
+        afterBlockComment: true,
+        beforeLineComment: true,
+        afterLineComment: false,
+        allowBlockStart: true,
+        allowBlockEnd: false,
+      }],
+      'linebreak-style': ['error', 'unix'],
+      'max-nested-callbacks': ['warn', 3],
+      'new-cap': 'off',
+      'no-alert': 'error',
+      'no-caller': 'error',
+      'no-delete-var': 'error',
+      'no-div-regex': 'error',
+      'no-duplicate-case': 'error',
+      'no-else-return': 'error',
+      'no-empty': 'error',
+      'no-empty-character-class': 'error',
+      'no-eval': 'error',
+      'no-extend-native': 'error',
+      'no-extra-semi': 'error',
+      'no-fallthrough': 'error',
+      'no-floating-decimal': 'error',
+      'no-func-assign': 'error',
+      'no-implied-eval': 'error',
+      'no-inline-comments': 'error',
+      'no-invalid-regexp': 'error',
+      'no-label-var': 'error',
+      'no-labels': 'error',
+      'no-lone-blocks': 'error',
+      'no-lonely-if': 'error',
+      'no-mixed-requires': 'off',
+      'no-mixed-spaces-and-tabs': 'error',
+      'no-multi-spaces': 'error',
+      'no-multi-str': 'error',
+      'no-multiple-empty-lines': ['error', {
+        max: 2,
+      }],
+      'no-nested-ternary': 'error',
+      'no-new-func': 'error',
+      'no-new-object': 'error',
+      'no-new-wrappers': 'error',
+      'no-octal-escape': 'error',
+      'no-octal': 'error',
+      'no-path-concat': 'error',
+      'no-param-reassign': 'off',
+      'no-process-env': 'off',
+      'no-proto': 'error',
+      'no-redeclare': 'error',
+      'no-return-assign': ['error', 'always'],
+      'no-self-compare': 'error',
+      'no-sequences': 'error',
+      'no-shadow': 'error',
+      'no-shadow-restricted-names': 'error',
+      'func-call-spacing': 'error',
+      'no-sparse-arrays': 'warn',
+      'no-sync': 'warn',
+      'no-ternary': 'off',
+      'no-throw-literal': 'error',
+      'no-trailing-spaces': 'error',
+      'no-undef': 'error',
+      'no-undef-init': 'error',
+      'no-undefined': 'error',
+      'no-underscore-dangle': 'error',
+      'no-unexpected-multiline': 'error',
+      'no-unneeded-ternary': 'error',
+      'no-unreachable': 'error',
+      'no-unused-vars': 'warn',
+      'no-use-before-define': 'error',
+      'no-useless-concat': 'error',
+      'no-warning-comments': 'warn',
+      'no-with': 'error',
+      'object-curly-spacing': ['error', 'always', {
+        objectsInObjects: false,
+        arraysInObjects: false,
+      }],
+      'one-var': ['error', 'never'],
+      'operator-assignment': ['error', 'always'],
+      'operator-linebreak': ['error', 'before'],
+      'padded-blocks': 'off',
+      'quote-props': ['error', 'consistent'],
+      'quotes': ['error', 'single', 'avoid-escape'],
+      'radix': 'error',
+      'semi': 'error',
+      'semi-spacing': ['error', {
+        before: false,
+        after: true,
+      }],
+      'space-before-blocks': ['error', 'always'],
+      'space-before-function-paren': ['error', 'always'],
+      'space-in-parens': ['error', 'always'],
+      'space-infix-ops': 'error',
+      'space-unary-ops': ['error', {
+        words: true,
+        nonwords: false,
+        overrides: {
+          '!': true,
+        },
+      }],
+      'spaced-comment': ['error', 'always'],
+      'use-isnan': 'error',
+      'valid-typeof': 'error',
+      'vars-on-top': 'error',
+      'wrap-regex': 'off',
+      'yoda': ['error', 'never'],
+    },
+  },
+];