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no-alert.js 4.19 KiB
/**
 * @fileoverview Rule to flag use of alert, confirm, prompt
 * @author Nicholas C. Zakas
 */
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const {
    getStaticPropertyName: getPropertyName,
    getVariableByName,
    skipChainExpression
} = require("./utils/ast-utils");
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
/**
 * Checks if the given name is a prohibited identifier.
 * @param {string} name The name to check
 * @returns {boolean} Whether or not the name is prohibited.
function isProhibitedIdentifier(name) {
    return /^(alert|confirm|prompt)$/u.test(name);
/**
 * Finds the eslint-scope reference in the given scope.
 * @param {Object} scope The scope to search.
 * @param {ASTNode} node The identifier node.
 * @returns {Reference|null} Returns the found reference or null if none were found.
function findReference(scope, node) {
    const references = scope.references.filter(reference => reference.identifier.range[0] === node.range[0] &&
            reference.identifier.range[1] === node.range[1]);
    if (references.length === 1) {
        return references[0];
    return null;
/**
 * Checks if the given identifier node is shadowed in the given scope.
 * @param {Object} scope The current scope.
 * @param {string} node The identifier node to check
 * @returns {boolean} Whether or not the name is shadowed.
function isShadowed(scope, node) {
    const reference = findReference(scope, node);
    return reference && reference.resolved && reference.resolved.defs.length > 0;
/**
 * Checks if the given identifier node is a ThisExpression in the global scope or the global window property.
 * @param {Object} scope The current scope.
 * @param {string} node The identifier node to check
 * @returns {boolean} Whether or not the node is a reference to the global object.
function isGlobalThisReferenceOrGlobalWindow(scope, node) {
    if (scope.type === "global" && node.type === "ThisExpression") {
        return true;
    if (
        node.type === "Identifier" &&
node.name === "window" || (node.name === "globalThis" && getVariableByName(scope, "globalThis")) ) ) { return !isShadowed(scope, node); } return false; } //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ module.exports = { meta: { type: "suggestion", docs: { description: "disallow the use of `alert`, `confirm`, and `prompt`", category: "Best Practices", recommended: false, url: "https://eslint.org/docs/rules/no-alert" }, schema: [], messages: { unexpected: "Unexpected {{name}}." } }, create(context) { return { CallExpression(node) { const callee = skipChainExpression(node.callee), currentScope = context.getScope(); // without window. if (callee.type === "Identifier") { const name = callee.name; if (!isShadowed(currentScope, callee) && isProhibitedIdentifier(callee.name)) { context.report({ node, messageId: "unexpected", data: { name } }); } } else if (callee.type === "MemberExpression" && isGlobalThisReferenceOrGlobalWindow(currentScope, callee.object)) { const name = getPropertyName(callee); if (isProhibitedIdentifier(name)) { context.report({ node, messageId: "unexpected", data: { name } }); } } } }; } };