eslint/lib/rules/no-multi-assign.js

   1 /**
   2  * @fileoverview Rule to check use of chained assignment expressions
   3  * @author Stewart Rand
   4  */
   5
   6 "use strict";
   7
   8
   9 //------------------------------------------------------------------------------
  10 // Rule Definition
  11 //------------------------------------------------------------------------------
  12
  13 /** @type {import('../shared/types').Rule} */
  14 module.exports = {
  15     meta: {
  16         type: "suggestion",
  17
  18         docs: {
  19             description: "Disallow use of chained assignment expressions",
  20             recommended: false,
  21             url: "https://eslint.org/docs/rules/no-multi-assign"
  22         },
  23
  24         schema: [{
  25             type: "object",
  26             properties: {
  27                 ignoreNonDeclaration: {
  28                     type: "boolean",
  29                     default: false
  30                 }
  31             },
  32             additionalProperties: false
  33         }],
  34
  35         messages: {
  36             unexpectedChain: "Unexpected chained assignment."
  37         }
  38     },
  39
  40     create(context) {
  41
  42         //--------------------------------------------------------------------------
  43         // Public
  44         //--------------------------------------------------------------------------
  45         const options = context.options[0] || {
  46             ignoreNonDeclaration: false
  47         };
  48         const selectors = [
  49             "VariableDeclarator > AssignmentExpression.init",
  50             "PropertyDefinition > AssignmentExpression.value"
  51         ];
  52
  53         if (!options.ignoreNonDeclaration) {
  54             selectors.push("AssignmentExpression > AssignmentExpression.right");
  55         }
  56
  57         return {
  58             [selectors](node) {
  59                 context.report({
  60                     node,
  61                     messageId: "unexpectedChain"
  62                 });
  63             }
  64         };
  65
  66     }
  67 };