2 * @fileoverview A rule to disallow duplicate name in class members.
3 * @author Toru Nagashima
8 const astUtils = require("./utils/ast-utils");
10 //------------------------------------------------------------------------------
12 //------------------------------------------------------------------------------
19 description: "disallow duplicate class members",
20 category: "ECMAScript 6",
22 url: "https://eslint.org/docs/rules/no-dupe-class-members"
28 unexpected: "Duplicate name '{{name}}'."
36 * Gets state of a given member name.
37 * @param {string} name A name of a member.
38 * @param {boolean} isStatic A flag which specifies that is a static member.
39 * @returns {Object} A state of a given member name.
40 * - retv.init {boolean} A flag which shows the name is declared as normal member.
41 * - retv.get {boolean} A flag which shows the name is declared as getter.
42 * - retv.set {boolean} A flag which shows the name is declared as setter.
44 function getState(name, isStatic) {
45 const stateMap = stack[stack.length - 1];
46 const key = `$${name}`; // to avoid "__proto__".
50 nonStatic: { init: false, get: false, set: false },
51 static: { init: false, get: false, set: false }
55 return stateMap[key][isStatic ? "static" : "nonStatic"];
60 // Initializes the stack of state of member declarations.
65 // Initializes state of member declarations for the class.
67 stack.push(Object.create(null));
70 // Disposes the state for the class.
75 // Reports the node if its name has been declared already.
76 MethodDefinition(node) {
77 const name = astUtils.getStaticPropertyName(node);
79 if (name === null || node.kind === "constructor") {
83 const state = getState(name, node.static);
84 let isDuplicate = false;
86 if (node.kind === "get") {
87 isDuplicate = (state.init || state.get);
89 } else if (node.kind === "set") {
90 isDuplicate = (state.init || state.set);
93 isDuplicate = (state.init || state.get || state.set);
98 context.report({ node, messageId: "unexpected", data: { name } });