radix.js

/**
 * @fileoverview Rule to flag use of parseInt without a radix argument
 * @author James Allardice
 */

"use strict";

//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------

const astUtils = require("./utils/ast-utils");

//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------

const MODE_ALWAYS = "always",
    MODE_AS_NEEDED = "as-needed";

const validRadixValues = new Set(Array.from({ length: 37 - 2 }, (_, index) => index + 2));

/**
 * Checks whether a given variable is shadowed or not.
 * @param {eslint-scope.Variable} variable A variable to check.
 * @returns {boolean} `true` if the variable is shadowed.
 */
function isShadowed(variable) {
    return variable.defs.length >= 1;
}

/**
 * Checks whether a given node is a MemberExpression of `parseInt` method or not.
 * @param {ASTNode} node A node to check.
 * @returns {boolean} `true` if the node is a MemberExpression of `parseInt`
 *      method.
 */
function isParseIntMethod(node) {
    return (
        node.type === "MemberExpression" &&
        !node.computed &&
        node.property.type === "Identifier" &&
        node.property.name === "parseInt"
    );
}

/**
 * Checks whether a given node is a valid value of radix or not.
 *
 * The following values are invalid.
 *
 * - A literal except integers between 2 and 36.
 * - undefined.
 * @param {ASTNode} radix A node of radix to check.
 * @returns {boolean} `true` if the node is valid.
 */
function isValidRadix(radix) {
    return !(
        (radix.type === "Literal" && !validRadixValues.has(radix.value)) ||
        (radix.type === "Identifier" && radix.name === "undefined")
    );
}

/**
 * Checks whether a given node is a default value of radix or not.
 * @param {ASTNode} radix A node of radix to check.
 * @returns {boolean} `true` if the node is the literal node of `10`.
 */
function isDefaultRadix(radix) {
    return radix.type === "Literal" && radix.value === 10;