eslint.config.js

const tsParser = require('@typescript-eslint/parser');
const js = require('@eslint/js');
const globals = require('globals');
const ts = require('@typescript-eslint/eslint-plugin');
const eslintConfigPrettier = require('eslint-config-prettier');
const prettier = require('eslint-plugin-prettier');
const stylisticJs = require('@stylistic/eslint-plugin-js');
const stylisticTs = require('@stylistic/eslint-plugin-ts');
const stylisticPlus =  require('@stylistic/eslint-plugin-plus')

module.exports = [
{
    files: [
        '**/*.ts',
        './src/**/*.ts',
        './test/**/*.ts'
    ],
    plugins: {
        '@typescript-eslint': ts,
        'prettier': prettier,
        '@stylistic/js': stylisticJs,
        '@stylistic/ts': stylisticTs,
        '@stylistic/plus': stylisticPlus
    },
    languageOptions: {
        parser: tsParser,
        globals: {
            ...globals.browser,
        },
        parserOptions: {
            project: ['tsconfig.json'],
        },
    },
    rules: {
        ...js.configs.recommended.rules,
        ...ts.configs['stylistic-type-checked'].rules,
        // eslint/js rules
        'indent': [1, 4],
        'space-before-function-paren': 0,
        'prefer-const': 1,
        'comma-dangle': 0,
        'keyword-spacing': ['error', { before: true, after: true }],
        'comma-spacing': ['error', { before: false, after: true }],
        'indent': 0,
        'prefer-spread': 1,
        'eqeqeq': ['error', 'smart'],
        'no-unexpected-multiline': 0,
        'no-prototype-builtins': 0,
        'no-useless-escape': 1,
        'no-mixed-operators': 1,
        'no-control-regex': 0,
        'no-console': 2,
        'no-var': 2,
        'no-undef': 0,
        'no-redeclare': 'error',
        'no-unused-vars': [
            'error',
            {
                'argsIgnorePattern': '^_',
                'varsIgnorePattern': '^_',
                'ignoreRestSiblings': true
            }
        ],

        '@stylistic/js/no-multi-spaces': [ 0, { ignoreEOLComments: true } ],
        '@stylistic/js/arrow-spacing': [ 'error', { before: true, after: true } ],
        '@stylistic/js/arrow-parens': [ 'error', 'always' ],

        '@stylistic/js/block-spacing': [ 'error', 'always' ],
        '@stylistic/ts/block-spacing': [ 'error', 'always' ],

        '@stylistic/js/brace-style': [ 'error', 'allman', { allowSingleLine: true } ],
        '@stylistic/ts/brace-style': [ 'error', 'allman', { allowSingleLine: true } ],

        '@stylistic/js/comma-dangle': [ 'error', 'never' ],
        '@stylistic/ts/comma-dangle': [ 'error', 'never' ],

        '@stylistic/js/comma-spacing': [ 'error', { before: false, after: true }],
        '@stylistic/ts/comma-spacing': [ 'error', { before: false, after: true }],

        '@stylistic/js/keyword-spacing': [ 'error', {
            before: true,
            after: true,
            'overrides':
            {
                return:     { before: true, after: true },
                throw:      { before: true, after: true },
                case:       { before: true, after: true },
                as:         { before: true, after: true },
                if:         { before: true, after: true },
                for:        { before: true, after: true },
                while:      { before: true, after: true },
                static:     { before: true, after: true }
            },
        }],

        '@stylistic/ts/keyword-spacing': ['error', {
            before: true,
            after: true,
            'overrides':
            {
                return:     { before: true, after: true },
                throw:      { before: true, after: true },
                case:       { before: true, after: true },
                as:         { before: true, after: true },
                if:         { before: true, after: true },
                for:        { before: true, after: true },
                while:      { before: true, after: true },
                static:     { before: true, after: true }
            },
        }],

        '@stylistic/js/computed-property-spacing': ['error', 'always'],
        '@stylistic/js/eol-last': ['error', 'always'],
        '@stylistic/js/jsx-quotes': ['error', 'prefer-single'],
        '@stylistic/js/linebreak-style': ['error', 'unix'],
        '@stylistic/js/no-mixed-spaces-and-tabs': ['error'],
        '@stylistic/js/no-tabs': ['error'],
        '@stylistic/js/no-trailing-spaces': ['error', { 'skipBlankLines': true, 'ignoreComments': true }],
        '@stylistic/js/no-whitespace-before-property': ['error'],

        '@stylistic/js/object-curly-spacing': ['error', 'always'],
        '@stylistic/ts/object-curly-spacing': ['error', 'always'],

        '@stylistic/js/quote-props': ['error', 'as-needed'],
        '@stylistic/ts/quote-props': ['error', 'as-needed'],

        '@stylistic/js/quotes': ['error', 'single', { 'allowTemplateLiterals': true }],
        '@stylistic/ts/quotes': ['error', 'single', { 'allowTemplateLiterals': true }],

        '@stylistic/js/semi': ['error', 'never'],
        '@stylistic/ts/semi': ['error', 'never'],

        '@stylistic/js/space-in-parens': ['error', 'always'],

        '@stylistic/js/space-infix-ops': ['error'],
        '@stylistic/ts/space-infix-ops': ['error'],

        '@stylistic/js/spaced-comment': ['error', 'always'],
        '@stylistic/js/template-curly-spacing': ['error', 'always'],
        '@stylistic/js/template-tag-spacing': ['error', 'always'],
        '@stylistic/js/wrap-iife': [2, "inside", { functionPrototypeMethods: true }],

        '@stylistic/plus/type-named-tuple-spacing': ["error"],
        '@stylistic/plus/type-generic-spacing': ["error"],

        // 'prettier/prettier': ['error'],
        // @typescript-eslint rules
        '@typescript-eslint/prefer-nullish-coalescing': 'off' // require `strictNullChecks`
    },
}];