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 /** @type {import('../shared/types').Rule} */
  20 module.exports = {
  21     meta: {
  22         type: "layout",
  23
  24         docs: {
  25             description: "disallow all tabs",
  26             recommended: false,
  27             url: "https://eslint.org/docs/rules/no-tabs"
  28         },
  29         schema: [{
  30             type: "object",
  31             properties: {
  32                 allowIndentationTabs: {
  33                     type: "boolean",
  34                     default: false
  35                 }
  36             },
  37             additionalProperties: false
  38         }],
  39
  40         messages: {
  41             unexpectedTab: "Unexpected tab character."
  42         }
  43     },
  44
  45     create(context) {
  46         const sourceCode = context.getSourceCode();
  47         const allowIndentationTabs = context.options && context.options[0] && context.options[0].allowIndentationTabs;
  48
  49         return {
  50             Program(node) {
  51                 sourceCode.getLines().forEach((line, index) => {
  52                     let match;
  53
  54                     while ((match = tabRegex.exec(line)) !== null) {
  55                         if (allowIndentationTabs && !anyNonWhitespaceRegex.test(line.slice(0, match.index))) {
  56                             continue;
  57                         }
  58
  59                         context.report({
  60                             node,
  61                             loc: {
  62                                 start: {
  63                                     line: index + 1,
  64                                     column: match.index
  65                                 },
  66                                 end: {
  67                                     line: index + 1,
  68                                     column: match.index + match[0].length
  69                                 }
  70                             },
  71                             messageId: "unexpectedTab"
  72                         });
  73                     }
  74                 });
  75             }
  76         };
  77     }
  78 };