whitespace.js

"use strict";

module.exports = {
  rules: {
    // disallow space inside array square brackets
    "array-bracket-spacing": "error",

    // require space before/after arrow function's arrow
    "arrow-spacing": "error",

    // require spaces inside of single-line blocks
    "block-spacing": "error",

    // enforce one true brace style
    "brace-style": [
      "error",
      "stroustrup",
      {
        // allow opening and closing brace to be on the same line
        allowSingleLine: true,
      },
    ],

    // enforce spacing after comma (but not before)
    "comma-spacing": [
      "warn",
      {
        before: false,
        after: true,
      },
    ],

    // require commas to be placed at the ends of lines
    "comma-style": "error",

    // disallow space inside computed property square brackets
    "computed-property-spacing": "error",

    // specify the placement of dots in multi-line statements
    "dot-location": [
      "error",
      "property",
    ],

    // enforce newline at the end of file, with no multiple empty lines
    "eol-last": "error",

    // disallow spaces after the function name in function calls
    "func-call-spacing": "error",

    // specify 2-space indentation
    indent: [
      "error",
      2,                        // 2 spaces
      {
        SwitchCase: 1,          // indent multipler for "switch" "case" statements
        VariableDeclarator: {
          var: 2,               // indent multiplier for multi-line "var" statements
          let: 2,               // indent multiplier for multi-line "let" statements
          const: 3,             // indent multiplier for multi-line "const" statements
        },
      },
    ],

    // enforces spacing between keys and values in object literal properties
    "key-spacing": [
      "error",
      {
        beforeColon: false,
        afterColon: true,
      },
    ],

    // require a space before and after keywords
    "keyword-spacing": "error",

    // disallow irregular whitespace outside of strings and comments
    "no-irregular-whitespace": "error",

    // disallow mixed spaces and tabs for indentation
    "no-mixed-spaces-and-tabs": "error",

    // disallow use of multiple spaces
    "no-multi-spaces": [
      "error",
      {
        ignoreEOLComments: true,    // allow multiple spaces before end-of-line comments (like this one!)
      }
    ],

    // disallow trailing whitespace at the end of lines
    "no-trailing-spaces": "error",

    // require a space around curly braces in object literals
    "object-curly-spacing": [
      "error",
      "always",
      {
        arraysInObjects: false,
        objectsInObjects: false
      }
    ],

    // require linebreaks to be placed after operators
    "operator-linebreak": "error",

    // enforce spacing after semicolons
    "semi-spacing": "error",

    // disallow space before blocks
    "space-before-blocks": "error",

    // require a space between the function name and left paren in function definitions
    "space-before-function-paren": "error",

    // disallow spaces inside parentheses
    "space-in-parens": "error",

    // require spaces around operators
    "space-infix-ops": "error",

    // disallow spaces before/after unary operators
    "space-unary-ops": "error",

    // require a space at the start of a comment
    "spaced-comment": [
      "error",
      "always",
      {
        line: {
          exceptions: ["/"],                       // exceptions for line comments
        },
        block: {
          exceptions: ["*", "!", "-", "=", "+"],   // exceptions for block comments
        },
      },
    ],
  }
};