| /** | |
|  * @fileoverview Rule to disallow an empty pattern | |
|  * @author Alberto Rodríguez | |
|  */ | |
| "use strict"; | |
| 
 | |
| const astUtils = require("./utils/ast-utils"); | |
| 
 | |
| //------------------------------------------------------------------------------ | |
| // Rule Definition | |
| //------------------------------------------------------------------------------ | |
|  | |
| /** @type {import('../shared/types').Rule} */ | |
| module.exports = { | |
|     meta: { | |
|         type: "problem", | |
| 
 | |
|         docs: { | |
|             description: "Disallow empty destructuring patterns", | |
|             recommended: true, | |
|             url: "https://eslint.org/docs/latest/rules/no-empty-pattern" | |
|         }, | |
| 
 | |
|         schema: [ | |
|             { | |
|                 type: "object", | |
|                 properties: { | |
|                     allowObjectPatternsAsParameters: { | |
|                         type: "boolean", | |
|                         default: false | |
|                     } | |
|                 }, | |
|                 additionalProperties: false | |
|             } | |
|         ], | |
| 
 | |
|         messages: { | |
|             unexpected: "Unexpected empty {{type}} pattern." | |
|         } | |
|     }, | |
| 
 | |
|     create(context) { | |
|         const options = context.options[0] || {}, | |
|             allowObjectPatternsAsParameters = options.allowObjectPatternsAsParameters || false; | |
| 
 | |
|         return { | |
|             ObjectPattern(node) { | |
| 
 | |
|                 if (node.properties.length > 0) { | |
|                     return; | |
|                 } | |
| 
 | |
|                 // Allow {} and {} = {} empty object patterns as parameters when allowObjectPatternsAsParameters is true | |
|                 if ( | |
|                     allowObjectPatternsAsParameters && | |
|                     ( | |
|                         astUtils.isFunction(node.parent) || | |
|                         ( | |
|                             node.parent.type === "AssignmentPattern" && | |
|                             astUtils.isFunction(node.parent.parent) && | |
|                             node.parent.right.type === "ObjectExpression" && | |
|                             node.parent.right.properties.length === 0 | |
|                         ) | |
|                     ) | |
|                 ) { | |
|                     return; | |
|                 } | |
| 
 | |
|                 context.report({ node, messageId: "unexpected", data: { type: "object" } }); | |
|             }, | |
|             ArrayPattern(node) { | |
|                 if (node.elements.length === 0) { | |
|                     context.report({ node, messageId: "unexpected", data: { type: "array" } }); | |
|                 } | |
|             } | |
|         }; | |
|     } | |
| };
 |