2 * @fileoverview Rule to flag use of parseInt without a radix argument
3 * @author James Allardice
8 //------------------------------------------------------------------------------
10 //------------------------------------------------------------------------------
12 const astUtils = require("./utils/ast-utils");
14 //------------------------------------------------------------------------------
16 //------------------------------------------------------------------------------
18 const MODE_ALWAYS = "always",
19 MODE_AS_NEEDED = "as-needed";
21 const validRadixValues = new Set(Array.from({ length: 37 - 2 }, (_, index) => index + 2));
24 * Checks whether a given variable is shadowed or not.
25 * @param {eslint-scope.Variable} variable A variable to check.
26 * @returns {boolean} `true` if the variable is shadowed.
28 function isShadowed(variable) {
29 return variable.defs.length >= 1;
33 * Checks whether a given node is a MemberExpression of `parseInt` method or not.
34 * @param {ASTNode} node A node to check.
35 * @returns {boolean} `true` if the node is a MemberExpression of `parseInt`
38 function isParseIntMethod(node) {
40 node.type === "MemberExpression" &&
42 node.property.type === "Identifier" &&
43 node.property.name === "parseInt"
48 * Checks whether a given node is a valid value of radix or not.
50 * The following values are invalid.
52 * - A literal except integers between 2 and 36.
54 * @param {ASTNode} radix A node of radix to check.
55 * @returns {boolean} `true` if the node is valid.
57 function isValidRadix(radix) {
59 (radix.type === "Literal" && !validRadixValues.has(radix.value)) ||
60 (radix.type === "Identifier" && radix.name === "undefined")
65 * Checks whether a given node is a default value of radix or not.
66 * @param {ASTNode} radix A node of radix to check.
67 * @returns {boolean} `true` if the node is the literal node of `10`.
69 function isDefaultRadix(radix) {
70 return radix.type === "Literal" && radix.value === 10;
73 //------------------------------------------------------------------------------
75 //------------------------------------------------------------------------------
82 description: "enforce the consistent use of the radix argument when using `parseInt()`",
83 category: "Best Practices",
85 url: "https://eslint.org/docs/rules/radix",
91 enum: ["always", "as-needed"]
96 missingParameters: "Missing parameters.",
97 redundantRadix: "Redundant radix parameter.",
98 missingRadix: "Missing radix parameter.",
99 invalidRadix: "Invalid radix parameter, must be an integer between 2 and 36.",
100 addRadixParameter10: "Add radix parameter `10` for parsing decimal numbers."
105 const mode = context.options[0] || MODE_ALWAYS;
108 * Checks the arguments of a given CallExpression node and reports it if it
110 * @param {ASTNode} node A CallExpression node to check.
113 function checkArguments(node) {
114 const args = node.arguments;
116 switch (args.length) {
120 messageId: "missingParameters"
125 if (mode === MODE_ALWAYS) {
128 messageId: "missingRadix",
131 messageId: "addRadixParameter10",
133 const sourceCode = context.getSourceCode();
134 const tokens = sourceCode.getTokens(node);
135 const lastToken = tokens[tokens.length - 1]; // Parenthesis.
136 const secondToLastToken = tokens[tokens.length - 2]; // May or may not be a comma.
137 const hasTrailingComma = secondToLastToken.type === "Punctuator" && secondToLastToken.value === ",";
139 return fixer.insertTextBefore(lastToken, hasTrailingComma ? " 10," : ", 10");
148 if (mode === MODE_AS_NEEDED && isDefaultRadix(args[1])) {
151 messageId: "redundantRadix"
153 } else if (!isValidRadix(args[1])) {
156 messageId: "invalidRadix"
165 const scope = context.getScope();
168 // Check `parseInt()`
169 variable = astUtils.getVariableByName(scope, "parseInt");
170 if (variable && !isShadowed(variable)) {
171 variable.references.forEach(reference => {
172 const node = reference.identifier;
174 if (astUtils.isCallee(node)) {
175 checkArguments(node.parent);
180 // Check `Number.parseInt()`
181 variable = astUtils.getVariableByName(scope, "Number");
182 if (variable && !isShadowed(variable)) {
183 variable.references.forEach(reference => {
184 const node = reference.identifier.parent;
185 const maybeCallee = node.parent.type === "ChainExpression"
189 if (isParseIntMethod(node) && astUtils.isCallee(maybeCallee)) {
190 checkArguments(maybeCallee.parent);