.config/coc/extensions/node_modules/coc-prettier/node_modules/eslint/lib/rules/no-undef-init.js

   1 /**
   2  * @fileoverview Rule to flag when initializing to undefined
   3  * @author Ilya Volodin
   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: "suggestion",
  17
  18         docs: {
  19             description: "disallow initializing variables to `undefined`",
  20             category: "Variables",
  21             recommended: false,
  22             url: "https://eslint.org/docs/rules/no-undef-init"
  23         },
  24
  25         schema: [],
  26         fixable: "code"
  27     },
  28
  29     create(context) {
  30
  31         const sourceCode = context.getSourceCode();
  32
  33         return {
  34
  35             VariableDeclarator(node) {
  36                 const name = sourceCode.getText(node.id),
  37                     init = node.init && node.init.name,
  38                     scope = context.getScope(),
  39                     undefinedVar = astUtils.getVariableByName(scope, "undefined"),
  40                     shadowed = undefinedVar && undefinedVar.defs.length > 0,
  41                     lastToken = sourceCode.getLastToken(node);
  42
  43                 if (init === "undefined" && node.parent.kind !== "const" && !shadowed) {
  44                     context.report({
  45                         node,
  46                         message: "It's not necessary to initialize '{{name}}' to undefined.",
  47                         data: { name },
  48                         fix(fixer) {
  49                             if (node.parent.kind === "var") {
  50                                 return null;
  51                             }
  52
  53                             if (node.id.type === "ArrayPattern" || node.id.type === "ObjectPattern") {
  54
  55                                 // Don't fix destructuring assignment to `undefined`.
  56                                 return null;
  57                             }
  58
  59                             if (sourceCode.commentsExistBetween(node.id, lastToken)) {
  60                                 return null;
  61                             }
  62
  63                             return fixer.removeRange([node.id.range[1], node.range[1]]);
  64                         }
  65                     });
  66                 }
  67             }
  68         };
  69
  70     }
  71 };