eslint/lib/rules/no-inline-comments.js

   1 /**
   2  * @fileoverview Enforces or disallows inline comments.
   3  * @author Greg Cochard
   4  */
   5 "use strict";
   6
   7 const astUtils = require("./utils/ast-utils");
   8
   9 //------------------------------------------------------------------------------
  10 // Rule Definition
  11 //------------------------------------------------------------------------------
  12
  13 module.exports = {
  14     meta: {
  15         type: "suggestion",
  16
  17         docs: {
  18             description: "disallow inline comments after code",
  19             recommended: false,
  20             url: "https://eslint.org/docs/rules/no-inline-comments"
  21         },
  22
  23         schema: [
  24             {
  25                 type: "object",
  26                 properties: {
  27                     ignorePattern: {
  28                         type: "string"
  29                     }
  30                 },
  31                 additionalProperties: false
  32             }
  33         ],
  34
  35         messages: {
  36             unexpectedInlineComment: "Unexpected comment inline with code."
  37         }
  38     },
  39
  40     create(context) {
  41         const sourceCode = context.getSourceCode();
  42         const options = context.options[0];
  43         let customIgnoreRegExp;
  44
  45         if (options && options.ignorePattern) {
  46             customIgnoreRegExp = new RegExp(options.ignorePattern, "u");
  47         }
  48
  49         /**
  50          * Will check that comments are not on lines starting with or ending with code
  51          * @param {ASTNode} node The comment node to check
  52          * @private
  53          * @returns {void}
  54          */
  55         function testCodeAroundComment(node) {
  56
  57             const startLine = String(sourceCode.lines[node.loc.start.line - 1]),
  58                 endLine = String(sourceCode.lines[node.loc.end.line - 1]),
  59                 preamble = startLine.slice(0, node.loc.start.column).trim(),
  60                 postamble = endLine.slice(node.loc.end.column).trim(),
  61                 isPreambleEmpty = !preamble,
  62                 isPostambleEmpty = !postamble;
  63
  64             // Nothing on both sides
  65             if (isPreambleEmpty && isPostambleEmpty) {
  66                 return;
  67             }
  68
  69             // Matches the ignore pattern
  70             if (customIgnoreRegExp && customIgnoreRegExp.test(node.value)) {
  71                 return;
  72             }
  73
  74             // JSX Exception
  75             if (
  76                 (isPreambleEmpty || preamble === "{") &&
  77                 (isPostambleEmpty || postamble === "}")
  78             ) {
  79                 const enclosingNode = sourceCode.getNodeByRangeIndex(node.range[0]);
  80
  81                 if (enclosingNode && enclosingNode.type === "JSXEmptyExpression") {
  82                     return;
  83                 }
  84             }
  85
  86             // Don't report ESLint directive comments
  87             if (astUtils.isDirectiveComment(node)) {
  88                 return;
  89             }
  90
  91             context.report({
  92                 node,
  93                 messageId: "unexpectedInlineComment"
  94             });
  95         }
  96
  97         //--------------------------------------------------------------------------
  98         // Public
  99         //--------------------------------------------------------------------------
 100
 101         return {
 102             Program() {
 103                 sourceCode.getAllComments()
 104                     .filter(token => token.type !== "Shebang")
 105                     .forEach(testCodeAroundComment);
 106             }
 107         };
 108     }
 109 };