new-parens.js•3.27 kB
/**
* @fileoverview Rule to flag when using constructor without parentheses
* @author Ilya Volodin
* @deprecated in ESLint v8.53.0
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const astUtils = require("./utils/ast-utils");
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../shared/types').Rule} */
module.exports = {
meta: {
deprecated: true,
replacedBy: [],
type: "layout",
docs: {
description: "Enforce or disallow parentheses when invoking a constructor with no arguments",
recommended: false,
url: "https://eslint.org/docs/latest/rules/new-parens"
},
fixable: "code",
schema: [
{
enum: ["always", "never"]
}
],
messages: {
missing: "Missing '()' invoking a constructor.",
unnecessary: "Unnecessary '()' invoking a constructor with no arguments."
}
},
create(context) {
const options = context.options;
const always = options[0] !== "never"; // Default is always
const sourceCode = context.sourceCode;
return {
NewExpression(node) {
if (node.arguments.length !== 0) {
return; // if there are arguments, there have to be parens
}
const lastToken = sourceCode.getLastToken(node);
const hasLastParen = lastToken && astUtils.isClosingParenToken(lastToken);
// `hasParens` is true only if the new expression ends with its own parens, e.g., new new foo() does not end with its own parens
const hasParens = hasLastParen &&
astUtils.isOpeningParenToken(sourceCode.getTokenBefore(lastToken)) &&
node.callee.range[1] < node.range[1];
if (always) {
if (!hasParens) {
context.report({
node,
messageId: "missing",
fix: fixer => fixer.insertTextAfter(node, "()")
});
}
} else {
if (hasParens) {
context.report({
node,
messageId: "unnecessary",
fix: fixer => [
fixer.remove(sourceCode.getTokenBefore(lastToken)),
fixer.remove(lastToken),
fixer.insertTextBefore(node, "("),
fixer.insertTextAfter(node, ")")
]
});
}
}
}
};
}
};