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/**
* @fileoverview Rule to disallow calls to the `Object` constructor without an argument
* @author Francesco Trotta
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const {
getVariableByName,
isArrowToken,
isStartOfExpressionStatement,
needsPrecedingSemicolon
} = require("./utils/ast-utils");
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../shared/types').Rule} */
module.exports = {
meta: {
type: "suggestion",
docs: {
description: "Disallow calls to the `Object` constructor without an argument",
recommended: false,
url: "https://eslint.org/docs/latest/rules/no-object-constructor"
},
hasSuggestions: true,
schema: [],
messages: {
preferLiteral: "The object literal notation {} is preferable.",
useLiteral: "Replace with '{{replacement}}'.",
useLiteralAfterSemicolon: "Replace with '{{replacement}}', add preceding semicolon."
}
},
create(context) {
const sourceCode = context.sourceCode;
/**
* Determines whether or not an object literal that replaces a specified node needs to be enclosed in parentheses.
* @param {ASTNode} node The node to be replaced.
* @returns {boolean} Whether or not parentheses around the object literal are required.
*/
function needsParentheses(node) {
if (isStartOfExpressionStatement(node)) {
return true;
}
const prevToken = sourceCode.getTokenBefore(node);
if (prevToken && isArrowToken(prevToken)) {
return true;
}
return false;
}
/**
* Reports on nodes where the `Object` constructor is called without arguments.
* @param {ASTNode} node The node to evaluate.
* @returns {void}
*/
function check(node) {
if (node.callee.type !== "Identifier" || node.callee.name !== "Object" || node.arguments.length) {
return;
}
const variable = getVariableByName(sourceCode.getScope(node), "Object");
if (variable && variable.identifiers.length === 0) {
let replacement;
let fixText;
let messageId = "useLiteral";
if (needsParentheses(node)) {
replacement = "({})";
if (needsPrecedingSemicolon(sourceCode, node)) {
fixText = ";({})";
messageId = "useLiteralAfterSemicolon";
} else {
fixText = "({})";
}
} else {
replacement = fixText = "{}";
}
context.report({
node,
messageId: "preferLiteral",
suggest: [
{
messageId,
data: { replacement },
fix: fixer => fixer.replaceText(node, fixText)
}
]
});
}
}
return {
CallExpression: check,
NewExpression: check
};
}
};