105 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			105 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| /**
 | |
|  * @fileoverview A rule to disallow duplicate name in class members.
 | |
|  * @author Toru Nagashima
 | |
|  */
 | |
| 
 | |
| "use strict";
 | |
| 
 | |
| const astUtils = require("./utils/ast-utils");
 | |
| 
 | |
| //------------------------------------------------------------------------------
 | |
| // Rule Definition
 | |
| //------------------------------------------------------------------------------
 | |
| 
 | |
| /** @type {import('../shared/types').Rule} */
 | |
| module.exports = {
 | |
|     meta: {
 | |
|         type: "problem",
 | |
| 
 | |
|         docs: {
 | |
|             description: "Disallow duplicate class members",
 | |
|             recommended: true,
 | |
|             url: "https://eslint.org/docs/latest/rules/no-dupe-class-members"
 | |
|         },
 | |
| 
 | |
|         schema: [],
 | |
| 
 | |
|         messages: {
 | |
|             unexpected: "Duplicate name '{{name}}'."
 | |
|         }
 | |
|     },
 | |
| 
 | |
|     create(context) {
 | |
|         let stack = [];
 | |
| 
 | |
|         /**
 | |
|          * Gets state of a given member name.
 | |
|          * @param {string} name A name of a member.
 | |
|          * @param {boolean} isStatic A flag which specifies that is a static member.
 | |
|          * @returns {Object} A state of a given member name.
 | |
|          *   - retv.init {boolean} A flag which shows the name is declared as normal member.
 | |
|          *   - retv.get {boolean} A flag which shows the name is declared as getter.
 | |
|          *   - retv.set {boolean} A flag which shows the name is declared as setter.
 | |
|          */
 | |
|         function getState(name, isStatic) {
 | |
|             const stateMap = stack[stack.length - 1];
 | |
|             const key = `$${name}`; // to avoid "__proto__".
 | |
| 
 | |
|             if (!stateMap[key]) {
 | |
|                 stateMap[key] = {
 | |
|                     nonStatic: { init: false, get: false, set: false },
 | |
|                     static: { init: false, get: false, set: false }
 | |
|                 };
 | |
|             }
 | |
| 
 | |
|             return stateMap[key][isStatic ? "static" : "nonStatic"];
 | |
|         }
 | |
| 
 | |
|         return {
 | |
| 
 | |
|             // Initializes the stack of state of member declarations.
 | |
|             Program() {
 | |
|                 stack = [];
 | |
|             },
 | |
| 
 | |
|             // Initializes state of member declarations for the class.
 | |
|             ClassBody() {
 | |
|                 stack.push(Object.create(null));
 | |
|             },
 | |
| 
 | |
|             // Disposes the state for the class.
 | |
|             "ClassBody:exit"() {
 | |
|                 stack.pop();
 | |
|             },
 | |
| 
 | |
|             // Reports the node if its name has been declared already.
 | |
|             "MethodDefinition, PropertyDefinition"(node) {
 | |
|                 const name = astUtils.getStaticPropertyName(node);
 | |
|                 const kind = node.type === "MethodDefinition" ? node.kind : "field";
 | |
| 
 | |
|                 if (name === null || kind === "constructor") {
 | |
|                     return;
 | |
|                 }
 | |
| 
 | |
|                 const state = getState(name, node.static);
 | |
|                 let isDuplicate = false;
 | |
| 
 | |
|                 if (kind === "get") {
 | |
|                     isDuplicate = (state.init || state.get);
 | |
|                     state.get = true;
 | |
|                 } else if (kind === "set") {
 | |
|                     isDuplicate = (state.init || state.set);
 | |
|                     state.set = true;
 | |
|                 } else {
 | |
|                     isDuplicate = (state.init || state.get || state.set);
 | |
|                     state.init = true;
 | |
|                 }
 | |
| 
 | |
|                 if (isDuplicate) {
 | |
|                     context.report({ node, messageId: "unexpected", data: { name } });
 | |
|                 }
 | |
|             }
 | |
|         };
 | |
|     }
 | |
| };
 |