.eslintrc.js

module.exports = {
    root: true,
    extends: [
        'eslint-config-airbnb-base',
        'eslint-config-airbnb-base/rules/strict',
    ],
    parserOptions: {
        ecmaVersion: 13,
        sourceType: 'module',
        ecmaFeatures: {
            impliedStrict: true,
        },
    },
    settings: {
        'import/resolver': {
            webpack: {
                config: 'webpack.config.js',
            },
        },
    },
    env: {
        browser: true,
        es6: true,
        amd: true,
        commonjs: true,
    },
    rules: {
        'no-trailing-spaces': 'warn',
        'padded-blocks': 'warn',
        'no-unused-vars': 'warn',
        'no-plusplus': 'off',
        // this option sets a specific tab width for your code
        // http://eslint.org/docs/rules/indent
        indent: ['warn', 4, {
            SwitchCase: 1,
            VariableDeclarator: 1,
            outerIIFEBody: 1,
            // MemberExpression: null,
            // CallExpression: {
            // parameters: null,
            // },
            FunctionDeclaration: {
                parameters: 1,
                body: 1,
            },
            FunctionExpression: {
                parameters: 1,
                body: 1,
            },
        }],
        'one-var': ['error', 'never'],
        'valid-jsdoc': ['error', {
            requireReturn: false,
            requireParamDescription: false,
            requireReturnDescription: false,
        }],
        // TODO reactivate this rule once a proper npm package is made
        // a good configuration might be:
        /* 'import/no-extraneous-dependencies': ['error', {
      devDependencies: ['test/**', 'tests/**', 'examples/**'],
    }], */
        'import/no-extraneous-dependencies': 'off',

        // TODO reactivate all the following rules

        // maybe 'no-mixed-operators': ['error', { allowSamePrecedence: true }],
        'no-mixed-operators': 'off',
        'no-use-before-define': ['error', { functions: false }],
        // should probably be
        // 'no-underscore-dangle': ['error', { allowAfterThis: true, allowAfterSuper: true }],
        'no-underscore-dangle': 'off',
        eqeqeq: 'off',
        // what len ? Airbnb does 100. github wraps line above 80
        'max-len': 'off',
        'no-param-reassign': 'off',
        'no-else-return': 'off',
        'no-var': 'error',
        'vars-on-top': 'off',
        'no-shadow': 'off',
        'no-restricted-properties': 'off',
        'prefer-spread': 'off',
        'prefer-destructuring': 'off',
        'function-paren-newline': 'off',
        'operator-linebreak': 'off',
        'object-curly-newline': 'off',
        curly: ['error', 'all'],
        'no-multiple-empty-lines': 'off',
        'no-restricted-globals': 'off',
        'implicit-arrow-linebreak': 'off',
        'prefer-promise-reject-errors': 'off',
        'no-multi-spaces': 'off',
        'import/no-cycle': 'off',
        'import/no-useless-path-segments': 'off',
        camelcase: 'off',
        'switch-colon-spacing': 'off',
        'lines-between-class-members': 'off',
        'no-bitwise': 'off',
        'no-restricted-syntax': 'off',
        'consistent-return': 'off',
        'brace-style': ['error', '1tbs', { allowSingleLine: true }],
        'new-cap': 'off',
        'no-continue': 'off',
        'no-console': ['warn', { allow: ['warn', 'error'] }],
        'class-methods-use-this': 'off',
        'arrow-parens': ['error', 'as-needed', { requireForBlockBody: true }],
        'max-classes-per-file': ['error', 4],
        'function-call-argument-newline': 'off',
        // change default-param-last to on, but there are several breaking changes or default params to add.
        'default-param-last': 'off',
    },
    globals: {
        __DEBUG__: false,
    },
};