148 lines
5.7 KiB
JavaScript
148 lines
5.7 KiB
JavaScript
/**
|
|
* @fileoverview Rule to disallow `parseInt()` in favor of binary, octal, and hexadecimal literals
|
|
* @author Annie Zhang, Henry Zhu
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Requirements
|
|
//------------------------------------------------------------------------------
|
|
|
|
const astUtils = require("./utils/ast-utils");
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Helpers
|
|
//------------------------------------------------------------------------------
|
|
|
|
const radixMap = new Map([
|
|
[2, { system: "binary", literalPrefix: "0b" }],
|
|
[8, { system: "octal", literalPrefix: "0o" }],
|
|
[16, { system: "hexadecimal", literalPrefix: "0x" }]
|
|
]);
|
|
|
|
/**
|
|
* Checks to see if a CallExpression's callee node is `parseInt` or
|
|
* `Number.parseInt`.
|
|
* @param {ASTNode} calleeNode The callee node to evaluate.
|
|
* @returns {boolean} True if the callee is `parseInt` or `Number.parseInt`,
|
|
* false otherwise.
|
|
*/
|
|
function isParseInt(calleeNode) {
|
|
return (
|
|
astUtils.isSpecificId(calleeNode, "parseInt") ||
|
|
astUtils.isSpecificMemberAccess(calleeNode, "Number", "parseInt")
|
|
);
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Rule Definition
|
|
//------------------------------------------------------------------------------
|
|
|
|
module.exports = {
|
|
meta: {
|
|
type: "suggestion",
|
|
|
|
docs: {
|
|
description: "disallow `parseInt()` and `Number.parseInt()` in favor of binary, octal, and hexadecimal literals",
|
|
category: "ECMAScript 6",
|
|
recommended: false,
|
|
url: "https://eslint.org/docs/rules/prefer-numeric-literals"
|
|
},
|
|
|
|
schema: [],
|
|
|
|
messages: {
|
|
useLiteral: "Use {{system}} literals instead of {{functionName}}()."
|
|
},
|
|
|
|
fixable: "code"
|
|
},
|
|
|
|
create(context) {
|
|
const sourceCode = context.getSourceCode();
|
|
|
|
//----------------------------------------------------------------------
|
|
// Public
|
|
//----------------------------------------------------------------------
|
|
|
|
return {
|
|
|
|
"CallExpression[arguments.length=2]"(node) {
|
|
const [strNode, radixNode] = node.arguments,
|
|
str = astUtils.getStaticStringValue(strNode),
|
|
radix = radixNode.value;
|
|
|
|
if (
|
|
str !== null &&
|
|
astUtils.isStringLiteral(strNode) &&
|
|
radixNode.type === "Literal" &&
|
|
typeof radix === "number" &&
|
|
radixMap.has(radix) &&
|
|
isParseInt(node.callee)
|
|
) {
|
|
|
|
const { system, literalPrefix } = radixMap.get(radix);
|
|
|
|
context.report({
|
|
node,
|
|
messageId: "useLiteral",
|
|
data: {
|
|
system,
|
|
functionName: sourceCode.getText(node.callee)
|
|
},
|
|
fix(fixer) {
|
|
if (sourceCode.getCommentsInside(node).length) {
|
|
return null;
|
|
}
|
|
|
|
const replacement = `${literalPrefix}${str}`;
|
|
|
|
if (+replacement !== parseInt(str, radix)) {
|
|
|
|
/*
|
|
* If the newly-produced literal would be invalid, (e.g. 0b1234),
|
|
* or it would yield an incorrect parseInt result for some other reason, don't make a fix.
|
|
*
|
|
* If `str` had numeric separators, `+replacement` will evaluate to `NaN` because unary `+`
|
|
* per the specification doesn't support numeric separators. Thus, the above condition will be `true`
|
|
* (`NaN !== anything` is always `true`) regardless of the `parseInt(str, radix)` value.
|
|
* Consequently, no autofixes will be made. This is correct behavior because `parseInt` also
|
|
* doesn't support numeric separators, but it does parse part of the string before the first `_`,
|
|
* so the autofix would be invalid:
|
|
*
|
|
* parseInt("1_1", 2) // === 1
|
|
* 0b1_1 // === 3
|
|
*/
|
|
return null;
|
|
}
|
|
|
|
const tokenBefore = sourceCode.getTokenBefore(node),
|
|
tokenAfter = sourceCode.getTokenAfter(node);
|
|
let prefix = "",
|
|
suffix = "";
|
|
|
|
if (
|
|
tokenBefore &&
|
|
tokenBefore.range[1] === node.range[0] &&
|
|
!astUtils.canTokensBeAdjacent(tokenBefore, replacement)
|
|
) {
|
|
prefix = " ";
|
|
}
|
|
|
|
if (
|
|
tokenAfter &&
|
|
node.range[1] === tokenAfter.range[0] &&
|
|
!astUtils.canTokensBeAdjacent(replacement, tokenAfter)
|
|
) {
|
|
suffix = " ";
|
|
}
|
|
|
|
return fixer.replaceText(node, `${prefix}${replacement}${suffix}`);
|
|
}
|
|
});
|
|
}
|
|
}
|
|
};
|
|
}
|
|
};
|