Current File : /var/www/html/node_modules/eslint/lib/rules/no-dupe-keys.js
/**
* @fileoverview Rule to flag use of duplicate keys in an object.
* @author Ian Christian Myers
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const astUtils = require("./utils/ast-utils");
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
const GET_KIND = /^(?:init|get)$/u;
const SET_KIND = /^(?:init|set)$/u;
/**
* The class which stores properties' information of an object.
*/
class ObjectInfo {
/**
* @param {ObjectInfo|null} upper The information of the outer object.
* @param {ASTNode} node The ObjectExpression node of this information.
*/
constructor(upper, node) {
this.upper = upper;
this.node = node;
this.properties = new Map();
}
/**
* Gets the information of the given Property node.
* @param {ASTNode} node The Property node to get.
* @returns {{get: boolean, set: boolean}} The information of the property.
*/
getPropertyInfo(node) {
const name = astUtils.getStaticPropertyName(node);
if (!this.properties.has(name)) {
this.properties.set(name, { get: false, set: false });
}
return this.properties.get(name);
}
/**
* Checks whether the given property has been defined already or not.
* @param {ASTNode} node The Property node to check.
* @returns {boolean} `true` if the property has been defined.
*/
isPropertyDefined(node) {
const entry = this.getPropertyInfo(node);
return (
(GET_KIND.test(node.kind) && entry.get) ||
(SET_KIND.test(node.kind) && entry.set)
);
}
/**
* Defines the given property.
* @param {ASTNode} node The Property node to define.
* @returns {void}
*/
defineProperty(node) {
const entry = this.getPropertyInfo(node);
if (GET_KIND.test(node.kind)) {
entry.get = true;
}
if (SET_KIND.test(node.kind)) {
entry.set = true;
}
}
}
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../shared/types').Rule} */
module.exports = {
meta: {
type: "problem",
docs: {
description: "disallow duplicate keys in object literals",
recommended: true,
url: "https://eslint.org/docs/rules/no-dupe-keys"
},
schema: [],
messages: {
unexpected: "Duplicate key '{{name}}'."
}
},
create(context) {
let info = null;
return {
ObjectExpression(node) {
info = new ObjectInfo(info, node);
},
"ObjectExpression:exit"() {
info = info.upper;
},
Property(node) {
const name = astUtils.getStaticPropertyName(node);
// Skip destructuring.
if (node.parent.type !== "ObjectExpression") {
return;
}
// Skip if the name is not static.
if (name === null) {
return;
}
// Reports if the name is defined already.
if (info.isPropertyDefined(node)) {
context.report({
node: info.node,
loc: node.key.loc,
messageId: "unexpected",
data: { name }
});
}
// Update info.
info.defineProperty(node);
}
};
}
};
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