eslint/lib/rules/no-multi-spaces.js

   1 /**
   2  * @fileoverview Disallow use of multiple spaces.
   3  * @author Nicholas C. Zakas
   4  */
   5
   6 "use strict";
   7
   8 const astUtils = require("./utils/ast-utils");
   9
  10 //------------------------------------------------------------------------------
  11 // Rule Definition
  12 //------------------------------------------------------------------------------
  13
  14 module.exports = {
  15     meta: {
  16         type: "layout",
  17
  18         docs: {
  19             description: "disallow multiple spaces",
  20             recommended: false,
  21             url: "https://eslint.org/docs/rules/no-multi-spaces"
  22         },
  23
  24         fixable: "whitespace",
  25
  26         schema: [
  27             {
  28                 type: "object",
  29                 properties: {
  30                     exceptions: {
  31                         type: "object",
  32                         patternProperties: {
  33                             "^([A-Z][a-z]*)+$": {
  34                                 type: "boolean"
  35                             }
  36                         },
  37                         additionalProperties: false
  38                     },
  39                     ignoreEOLComments: {
  40                         type: "boolean",
  41                         default: false
  42                     }
  43                 },
  44                 additionalProperties: false
  45             }
  46         ],
  47
  48         messages: {
  49             multipleSpaces: "Multiple spaces found before '{{displayValue}}'."
  50         }
  51     },
  52
  53     create(context) {
  54         const sourceCode = context.getSourceCode();
  55         const options = context.options[0] || {};
  56         const ignoreEOLComments = options.ignoreEOLComments;
  57         const exceptions = Object.assign({ Property: true }, options.exceptions);
  58         const hasExceptions = Object.keys(exceptions).filter(key => exceptions[key]).length > 0;
  59
  60         /**
  61          * Formats value of given comment token for error message by truncating its length.
  62          * @param {Token} token comment token
  63          * @returns {string} formatted value
  64          * @private
  65          */
  66         function formatReportedCommentValue(token) {
  67             const valueLines = token.value.split("\n");
  68             const value = valueLines[0];
  69             const formattedValue = `${value.slice(0, 12)}...`;
  70
  71             return valueLines.length === 1 && value.length <= 12 ? value : formattedValue;
  72         }
  73
  74         //--------------------------------------------------------------------------
  75         // Public
  76         //--------------------------------------------------------------------------
  77
  78         return {
  79             Program() {
  80                 sourceCode.tokensAndComments.forEach((leftToken, leftIndex, tokensAndComments) => {
  81                     if (leftIndex === tokensAndComments.length - 1) {
  82                         return;
  83                     }
  84                     const rightToken = tokensAndComments[leftIndex + 1];
  85
  86                     // Ignore tokens that don't have 2 spaces between them or are on different lines
  87                     if (
  88                         !sourceCode.text.slice(leftToken.range[1], rightToken.range[0]).includes("  ") ||
  89                         leftToken.loc.end.line < rightToken.loc.start.line
  90                     ) {
  91                         return;
  92                     }
  93
  94                     // Ignore comments that are the last token on their line if `ignoreEOLComments` is active.
  95                     if (
  96                         ignoreEOLComments &&
  97                         astUtils.isCommentToken(rightToken) &&
  98                         (
  99                             leftIndex === tokensAndComments.length - 2 ||
 100                             rightToken.loc.end.line < tokensAndComments[leftIndex + 2].loc.start.line
 101                         )
 102                     ) {
 103                         return;
 104                     }
 105
 106                     // Ignore tokens that are in a node in the "exceptions" object
 107                     if (hasExceptions) {
 108                         const parentNode = sourceCode.getNodeByRangeIndex(rightToken.range[0] - 1);
 109
 110                         if (parentNode && exceptions[parentNode.type]) {
 111                             return;
 112                         }
 113                     }
 114
 115                     let displayValue;
 116
 117                     if (rightToken.type === "Block") {
 118                         displayValue = `/*${formatReportedCommentValue(rightToken)}*/`;
 119                     } else if (rightToken.type === "Line") {
 120                         displayValue = `//${formatReportedCommentValue(rightToken)}`;
 121                     } else {
 122                         displayValue = rightToken.value;
 123                     }
 124
 125                     context.report({
 126                         node: rightToken,
 127                         loc: { start: leftToken.loc.end, end: rightToken.loc.start },
 128                         messageId: "multipleSpaces",
 129                         data: { displayValue },
 130                         fix: fixer => fixer.replaceTextRange([leftToken.range[1], rightToken.range[0]], " ")
 131                     });
 132                 });
 133             }
 134         };
 135
 136     }
 137 };