.eslintrc.js

module.exports = {
    'extends': [
        'plugin:vue/essential', // where applicable
        'eslint:recommended',
        '@vue/standard', // where applicable
        'plugin:vue/strongly-recommended'
    ],
    rules: {
        'vue/html-closing-bracket-newline': [
            'error', {
                'singleline': 'never',
                'multiline': 'never'
            }
        ],
        'vue/html-indent': [
            'error', 4, {
                'attribute': 1,
                'baseIndent': 1,
                'closeBracket': 0,
                'alignAttributesVertically': false,
                'ignores': []
            }
        ],
        'vue/max-attributes-per-line': [ 'error', {
            "singleline": 1,
            "multiline": 1
          }
        ],
        'vue/no-mutating-props': 1,
        // These rules assume eslint recommended, if the rules is accepted from
        // eslint:recommended settings it is commented out and noted to the right of
        /*
         * the rule. This is intended to not overwrite any accepted rules.
         * 0 indicates no action, 1 is a warning, and 2 is an error.
         */
        /* possible error section */
        /*
         * 'for-direction': 0, // eslint:recommended
         * 'getter-return': 2, // eslint:recommended
         */
        'no-async-promise-executor': 1,
        'promise/param-names': 1,
        'vue/attribute-hyphenation': 0,
        'no-await-in-loops': 0,
        /*
         * 'no-compare-neg-zero': 1, // eslint:recommended
         * 'no-cond-assign': 0, // eslint:recommended
         */
        'no-console': process.env.NODE_ENV === 'production' ? 'error' : 'off',
        'no-constant-condition': 2,
        // 'no-control-regex': 2, // eslint:recommended
        'no-debugger': process.env.NODE_ENV === 'production' ? 'error' : 'off',
        /*
         * 'no-dupe-args': 2, // eslint:recommended
         * 'no-dupe-keys': 2 // eslint:recommended
         * 'no-duplicate-case': 2, // eslint:recommended
         * 'no-empty': 2, // eslint:recommended
         * 'no-empty-character-class': 2, // eslint:recommended
         * 'no-ex-assign': 2, // eslint:recommended
         * 'no-extra-boolean-cast': 2, // eslint:recommended
         * 'no-ex-assign': 2, // eslint:recommended
         */
        'import/no-webpack-loader-syntax': 0,
        'no-extra-parens': 2,
        'no-extra-semi': 2, // eslint:recommended
        /*
         * 'no-function-assign': 2, // eslint:recommended
         * 'no-invalid-regexp': 2, // eslint:recommended
         */
        'no-inner-declarations': 0, // eslint:recommended
        'no-irregular-whitespace': 2, // eslint:recommended
        /*
         * 'no-misleading-character-class': 0,
         * 'no-object-calls': 2, // eslint:recommended
         * 'no-protoype-bulletins': 0,
         * 'no-regex-spaces': 2, // eslint:recommended
         * 'no-sparse-arrays': 2, // eslint:recommended
         * 'no-template-curly-in-string': 2, // eslint:recommended
         * 'no-unexpected-multiline': 2, // eslint:recommended
         * 'no-unreachable': 2, // eslint:recommended
         * 'no-unsafe-funally': 2, // eslint:recommended
         * 'require-atomic-updates': 2, // eslint:recommended
         * 'use-isnan': 2, // eslint:recommended
         * 'valid-typeof': 2, // eslint:recommended
         */

        /** *** best practices *****/
        /*
         * 'accessor-pairs': 0,
         * 'array-callback-return': 0,
         * 'blocked-scoped-var': 0,
         * 'class-methods-use-this': 0,
         * 'complexity': 0,
         * 'consistent-return': 0,
         * 'curly': 2,  // eslint: recommended
         */
        'default-case': 2,
        'vue/valid-v-for':0,
        'vue/require-v-for-key':0,
        'vue/require-default-prop':0,
        /*
         * 'dot-location': 2 // eslint: recommended
         * 'dot-notation': 2 // eslint: recommended
         * 'eqeqeq': 2 // eslint: recommended
         * 'guard-for-in': 2, // ?? double check me - require for-in loops to include an if statement
         * 'max-classes-per-file': 0,
         * 'no-alert': 0,
         */
        'no-caller': 2, // Notes: deprecated
        /*
         * 'no-case-declarations': 2, // eslint: recommended
         * 'no-div-regex': 0,
         * 'no-else-return': 0,
         * 'no-empty-function': 0,
         * 'no-empty-pattern': 0, // eslint: recommended
         * 'no-eq-null': 0,
         */
        'no-eval': 1, // 5.8 Warning: Do not use the eval keyword without a really good reason.
        /*
         * 'no-extend-native': 2,  // ?? double check - disallow extending native types
         * 'no-extra-bind': 2,  // ?? double check - disallow unnecessary calls to .bind()
         * 'no-extra-label': 0,
         */
        'no-fallthrough': 1, // Set to warn: 5.7 allows fallthrough cases requires stated
        /*
         * 'no-floating-decimal': 0,
         * 'no-global-assign': 2, // eslint: recommended
         * 'no-implicit-coercion': 0,
         * 'no-implicit-globals': 0,
         * 'no-implied-eval': 0,
         * 'no-invalid-this': 2, // ?? double check - disallow this keywords outside of classes or class-like objects
         * 'no-iterator': 0,
         * 'no-labels': 0,
         * 'no-lone-blocks': 0,
         * 'no-loop-func: 0,
         * 'no-magic-numbers': 0,
         */
        'no-multi-spaces': 2, // Notes: disallow multiple spaces
        'no-multi-str': 2, // 4.6 Disallow Multiline Strings (no-multi-str)
        'no-redeclare': 0, // eslint: recommended
        'no-proto': 0,
        /*
         *'no-new': 0,
         * 'no-new-func': 0,
         * 'no-new-wrappers': 2,  // 5.8 Dissalowed
         * 'no-octal': 2, // eslint: recommended
         * 'no-octal-escape': 0,
         * 'no-param-reassign': 0,
         * 
         * 
         * 'no-restricted-properties': 0,
         * 'no-return-assign': 0,
         * 'no-return-await': 0,
         * 'no-script-url': 0,
         * 'no-self-assign': 2, // eslint: recommended
         * 'no-self-compare': 0,
         * 'no-sequences': 0,
         * 'no-throw-literal': 2, // notes: disallow throwing literals as exceptions
         * 'no-unified-loop-condition': 0,
         * 'no-unused-expressions': 0,
         * 'no-unused-labels': 2, // eslint: recommended
         * 'no-no-useless-call': 0,
         * 'no-useless-catch': 0,
         * 'no-useless-concat': 0,
         * 'no-useless-escape': 2, // eslint: recommended
         * 'no-useless-return': 0,
         * 'no-void': 0,
         * 'no-warning-comments': 0,
         */
        'no-with': 2,
        /*
         * 'no-prefer-promise-reject-errors': 2, notes: require using Error objects as Promise rejection reasons
         * 'no-radix': 0,
         * 'no-require-await': 0,
         * 'no-require-unicode-regexp': 0,
         * 'no-vars-on-top': 0,
         * 'no-wrap-life': 0,
         * 'no-yoda': 0,
         */

        /** ** strict mode ****/
        // 'strict': 0,

        /** ** variables ****/
        /*
         * 'init-declarations': 0,
         * 'no-delete-var': 2,   // eslint: recommended
         * 'no-label-var': 0,
         * 'no-restricted-globals': 0,
         * 'no-shadow': 0,
         * 'no-shadow-restricted-names': 0,
         * 
         * 'no-indef-init': 0,
         * 'no-undefined': 0,
         */
        'no-undef': 0, // eslint: recommended
        'require-default-prop':0,
        'no-unused-vars': 1, // eslint: recommended --- check
        // 'no-use-before-define': 0,

        /* Node.js and CommonJS */
        /*
         * 'callback-return': 0,
         * 'global-require': 0,
         * 'handle-callback-err': 0,
         * 'no-buffer-constructor': 0,
         * 'no-mixed-requires': 0,
         * 'no-new-require': 0,
         * 'no-path-concat': 0,
         * 'no-process-env': 0,
         * 'no-process-exit': 0,
         * 'no-restricted-modules': 0,
         * 'no-sync': ,
         */

        /** ** stylistic ****/
        'array-bracket-newline': 2, // notes: 3.1
        /*
         * 'array-bracket-spacing': 0, // no rule: enforce consistent spacing inside array brackets
         * 'array-element-newline': 0, // no rule: enforce line breaks after each array element
         * 'block-spacing': 0, // no rule
         */
        'brace-style': 2, // Notes: The presumed 'one true brace style' seemds to fit  3.1
        'camelcase': [
            1, {
                properties: 'always'
            }
        ], // notes: double check properties, not mentioned in 1.1
        // 'capitalized-comments': 0, // no rule
        'comma-dangle': [2, 'never'], // 4.2
        'comma-spacing': [
            2, {
                'before': false,
                'after': true
            }
        ], // 3.6.2
        'comma-style': [2, 'last'], // 3.6.2
        'computed-property-spacing': [2, 'never'], // double check 3.6.2
        // 'consistent-this': 0,
        'eol-last': 0, // double check me not explictely stated from what I can see
        'func-call-spacing': [2, 'never'], // 3.6.2 trailing whitespace forbidden without exception
        /*
         * 'func-name-matching': 0,
         * 'func-names': 0,
         * 'function-paren-newline': 0, // notes: dependant on case
         * 'func-style': 0, // both allowed
         * 'id-blacklist': 0, // none for now
         * 'id-length': 0,
         * 'id-match': 0,
         */
        'indent': ['error', 4],
        // 'jsx-quotes': 0, // depends
        'key-spacing': 2, // 3.6.2
        'keyword-spacing': 2, // 3.6.2
        /*
         * 'line-comment-position': 0, // 3.6.2 above and below are accepted
         * 'linebreak-style': 2,
         * 'lines-around-comment': 0,
         * 'lines-between-class-members': 0,
         * 'max-depth': 0,
         */
        'max-len': [
            2, { // should we ignore urls or anything here?
                code: 2400,
                tabWidth: 4
            }
        ],
        /*
         * 'max-lines': 0,
         * 'max-lines-per-function': 0,
         * 'max-nested-callbacks': 0,
         * 'max-params': 0,
         * 'max-statements': 0,
         * 'max-statements-per-line': 0,
         * 'multiline-comment-style': [2, 'starred-block'],
        */
        /*
         * 'multiline-ternary': 0,
         * 'new-cap': 2, // use array declarative instead
         * 'new-parens': 0, // same as above
         * 'newline-per-chained-call': 0, // notes: we do this in cass with d3, but not explicitely stated
         */
        'no-array-constructor': 2, // use array declarative instead
        /*
         * 'no-bitwise': 0,
         * 'no-continue': 0,
         * 'no-inline-comments': 0,
         * 'no-lonely-if': 0,
         * 'no-mixed-operators': 0,
         */
        'no-mixed-spaces-and-tabs': 2, // eslint:recommended
        // 'no-multi-assign': 0,
        'no-multiple-empty-lines': [
            1, {
                max: 2
            }
        ], // 3.6.1 permitted but not encouraged set to warn
        /*
         * 'no-negated-condition': 0,
         * 'no-nested-ternary': 0,
         */
        'no-new-object': 2, // 4.3
        /*
         * 'no-plusplus': 0,
         * 'no-restricted-syntax': 0,
         */
        'no-tabs': 2,
        // 'no-ternary': 0,
        'no-trailing-spaces': 2,
        /*
         * 'no-underscore-dangle': 0,
         * 'no-unneeded-ternary': 0,
         * 'no-whitespace-before-property': 0,
         * 'nonblock-statement-body-position': 0,
         * 'object-curly-newline': 0,
         */
        'object-curly-spacing': [2, 'never'], // 3.6.2 double check exceptions
        // 'object-property-newline': 0,
        'one-var': [
            2, { // 4.1
                var: 'never',
                let: 'never',
                const: 'never'
            }
        ],
        /*
         * 'one-var-declaration-per-line': 2, // not required because of above rule
         * 'operator-assignment': 0,
         * 'operator-linebreak': 0,
         */
        'padded-blocks': [2, 'never'], // 3.6.1 implied?
        /*
         * 'padding-line-between-statements': 0,
         * 'prefer-object-spread': 0,
         * 'quote-props': [2, 'consistent'],   // 4.3 should we make this consistent by object but not by file?
         * 
         */
        'quotes': [0, 'single', {
            allowTemplateLiterals: true
        }], // not reinforced
        'semi': [2, 'always'], // require semicol
        'semi-spacing': 2, // 3.6.2
        /*
         * 'semi-style': 0,
         * 'sort-keys': 0,
         * 'sort-vars': 0,
         */
        'space-before-blocks': 2, // 3.6.2
        'space-before-function-paren': [
            2, { // double check 3.6.2
                asyncArrow: 'never',
                anonymous: 'never',
                named: 'never'
            }
        ],
        /*
         * 'space-in-parens': 0,
         * 'space-infix-ops': 0,
         * 'space-unary-ops': 0,
         */
        'spaced-comment': [2, 'always'] // 2.3
        /*
         * 'switch-colon-spacing': 2, // 5.7.2 no rule
         * 'template-tag-spacing': 0,
         * 'unicode-bom': 0,
         * 'wrap-regex': 0,
         */,
         'vue/multi-word-component-names': 1

    },
    parserOptions: {
        parser: 'babel-eslint'
    }
};