eslint/lib/rules/no-tabs.js

   1 /**
   2  * @fileoverview Rule to check for tabs inside a file
   3  * @author Gyandeep Singh
   4  */
   5
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Helpers
  10 //------------------------------------------------------------------------------
  11
  12 const tabRegex = /\t+/gu;
  13 const anyNonWhitespaceRegex = /\S/u;
  14
  15 //------------------------------------------------------------------------------
  16 // Public Interface
  17 //------------------------------------------------------------------------------
  18
  19 module.exports = {
  20     meta: {
  21         type: "layout",
  22
  23         docs: {
  24             description: "disallow all tabs",
  25             recommended: false,
  26             url: "https://eslint.org/docs/rules/no-tabs"
  27         },
  28         schema: [{
  29             type: "object",
  30             properties: {
  31                 allowIndentationTabs: {
  32                     type: "boolean",
  33                     default: false
  34                 }
  35             },
  36             additionalProperties: false
  37         }],
  38
  39         messages: {
  40             unexpectedTab: "Unexpected tab character."
  41         }
  42     },
  43
  44     create(context) {
  45         const sourceCode = context.getSourceCode();
  46         const allowIndentationTabs = context.options && context.options[0] && context.options[0].allowIndentationTabs;
  47
  48         return {
  49             Program(node) {
  50                 sourceCode.getLines().forEach((line, index) => {
  51                     let match;
  52
  53                     while ((match = tabRegex.exec(line)) !== null) {
  54                         if (allowIndentationTabs && !anyNonWhitespaceRegex.test(line.slice(0, match.index))) {
  55                             continue;
  56                         }
  57
  58                         context.report({
  59                             node,
  60                             loc: {
  61                                 start: {
  62                                     line: index + 1,
  63                                     column: match.index
  64                                 },
  65                                 end: {
  66                                     line: index + 1,
  67                                     column: match.index + match[0].length
  68                                 }
  69                             },
  70                             messageId: "unexpectedTab"
  71                         });
  72                     }
  73                 });
  74             }
  75         };
  76     }
  77 };