Current File : /home/vacivi36/.trash/vacivitta/node_modules/eslint/lib/rules/no-dupe-class-members.js
/**
* @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('../types').Rule.RuleModule} */
module.exports = {
meta: {
type: "problem",
dialects: ["javascript", "typescript"],
language: "javascript",
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.at(-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) {
if (
node.value &&
node.value.type === "TSEmptyBodyFunctionExpression"
) {
return;
}
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;
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 },
});
}
},
};
},
};
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