83 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| /**
 | |
|  * @fileoverview Rule to flag duplicate arguments
 | |
|  * @author Jamund Ferguson
 | |
|  */
 | |
| 
 | |
| "use strict";
 | |
| 
 | |
| //------------------------------------------------------------------------------
 | |
| // Rule Definition
 | |
| //------------------------------------------------------------------------------
 | |
| 
 | |
| /** @type {import('../shared/types').Rule} */
 | |
| module.exports = {
 | |
|     meta: {
 | |
|         type: "problem",
 | |
| 
 | |
|         docs: {
 | |
|             description: "Disallow duplicate arguments in `function` definitions",
 | |
|             recommended: true,
 | |
|             url: "https://eslint.org/docs/latest/rules/no-dupe-args"
 | |
|         },
 | |
| 
 | |
|         schema: [],
 | |
| 
 | |
|         messages: {
 | |
|             unexpected: "Duplicate param '{{name}}'."
 | |
|         }
 | |
|     },
 | |
| 
 | |
|     create(context) {
 | |
| 
 | |
|         const sourceCode = context.sourceCode;
 | |
| 
 | |
|         //--------------------------------------------------------------------------
 | |
|         // Helpers
 | |
|         //--------------------------------------------------------------------------
 | |
| 
 | |
|         /**
 | |
|          * Checks whether or not a given definition is a parameter's.
 | |
|          * @param {eslint-scope.DefEntry} def A definition to check.
 | |
|          * @returns {boolean} `true` if the definition is a parameter's.
 | |
|          */
 | |
|         function isParameter(def) {
 | |
|             return def.type === "Parameter";
 | |
|         }
 | |
| 
 | |
|         /**
 | |
|          * Determines if a given node has duplicate parameters.
 | |
|          * @param {ASTNode} node The node to check.
 | |
|          * @returns {void}
 | |
|          * @private
 | |
|          */
 | |
|         function checkParams(node) {
 | |
|             const variables = sourceCode.getDeclaredVariables(node);
 | |
| 
 | |
|             for (let i = 0; i < variables.length; ++i) {
 | |
|                 const variable = variables[i];
 | |
| 
 | |
|                 // Checks and reports duplications.
 | |
|                 const defs = variable.defs.filter(isParameter);
 | |
| 
 | |
|                 if (defs.length >= 2) {
 | |
|                     context.report({
 | |
|                         node,
 | |
|                         messageId: "unexpected",
 | |
|                         data: { name: variable.name }
 | |
|                     });
 | |
|                 }
 | |
|             }
 | |
|         }
 | |
| 
 | |
|         //--------------------------------------------------------------------------
 | |
|         // Public API
 | |
|         //--------------------------------------------------------------------------
 | |
| 
 | |
|         return {
 | |
|             FunctionDeclaration: checkParams,
 | |
|             FunctionExpression: checkParams
 | |
|         };
 | |
| 
 | |
|     }
 | |
| };
 |