template-tag-spacing.js

   1 /**
   2  * @fileoverview Rule to check spacing between template tags and their literals
   3  * @author Jonathan Wilsson
   4  */
   5
   6 "use strict";
   7
   8 //------------------------------------------------------------------------------
   9 // Rule Definition
  10 //------------------------------------------------------------------------------
  11
  12 module.exports = {
  13     meta: {
  14         type: "layout",
  15
  16         docs: {
  17             description: "require or disallow spacing between template tags and their literals",
  18             category: "Stylistic Issues",
  19             recommended: false,
  20             url: "https://eslint.org/docs/rules/template-tag-spacing"
  21         },
  22
  23         fixable: "whitespace",
  24
  25         schema: [
  26             { enum: ["always", "never"] }
  27         ],
  28         messages: {
  29             unexpected: "Unexpected space between template tag and template literal.",
  30             missing: "Missing space between template tag and template literal."
  31         }
  32     },
  33
  34     create(context) {
  35         const never = context.options[0] !== "always";
  36         const sourceCode = context.getSourceCode();
  37
  38         /**
  39          * Check if a space is present between a template tag and its literal
  40          * @param {ASTNode} node node to evaluate
  41          * @returns {void}
  42          * @private
  43          */
  44         function checkSpacing(node) {
  45             const tagToken = sourceCode.getTokenBefore(node.quasi);
  46             const literalToken = sourceCode.getFirstToken(node.quasi);
  47             const hasWhitespace = sourceCode.isSpaceBetweenTokens(tagToken, literalToken);
  48
  49             if (never && hasWhitespace) {
  50                 context.report({
  51                     node,
  52                     loc: tagToken.loc.start,
  53                     messageId: "unexpected",
  54                     fix(fixer) {
  55                         const comments = sourceCode.getCommentsBefore(node.quasi);
  56
  57                         // Don't fix anything if there's a single line comment after the template tag
  58                         if (comments.some(comment => comment.type === "Line")) {
  59                             return null;
  60                         }
  61
  62                         return fixer.replaceTextRange(
  63                             [tagToken.range[1], literalToken.range[0]],
  64                             comments.reduce((text, comment) => text + sourceCode.getText(comment), "")
  65                         );
  66                     }
  67                 });
  68             } else if (!never && !hasWhitespace) {
  69                 context.report({
  70                     node,
  71                     loc: tagToken.loc.start,
  72                     messageId: "missing",
  73                     fix(fixer) {
  74                         return fixer.insertTextAfter(tagToken, " ");
  75                     }
  76                 });
  77             }
  78         }
  79
  80         return {
  81             TaggedTemplateExpression: checkSpacing
  82         };
  83     }
  84 };