Permalink
Cannot retrieve contributors at this time
| /** | |
| * @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 | |
| //------------------------------------------------------------------------------ | |
| /** | |
| * 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) { | |
| switch (calleeNode.type) { | |
| case "Identifier": | |
| return calleeNode.name === "parseInt"; | |
| case "MemberExpression": | |
| return calleeNode.object.type === "Identifier" && | |
| calleeNode.object.name === "Number" && | |
| calleeNode.property.type === "Identifier" && | |
| calleeNode.property.name === "parseInt"; | |
| // no default | |
| } | |
| return false; | |
| } | |
| //------------------------------------------------------------------------------ | |
| // 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: [], | |
| fixable: "code" | |
| }, | |
| create(context) { | |
| const sourceCode = context.getSourceCode(); | |
| const radixMap = { | |
| 2: "binary", | |
| 8: "octal", | |
| 16: "hexadecimal" | |
| }; | |
| const prefixMap = { | |
| 2: "0b", | |
| 8: "0o", | |
| 16: "0x" | |
| }; | |
| //---------------------------------------------------------------------- | |
| // Public | |
| //---------------------------------------------------------------------- | |
| return { | |
| CallExpression(node) { | |
| // doesn't check parseInt() if it doesn't have a radix argument | |
| if (node.arguments.length !== 2) { | |
| return; | |
| } | |
| // only error if the radix is 2, 8, or 16 | |
| const radixName = radixMap[node.arguments[1].value]; | |
| if (isParseInt(node.callee) && | |
| radixName && | |
| node.arguments[0].type === "Literal" | |
| ) { | |
| context.report({ | |
| node, | |
| message: "Use {{radixName}} literals instead of {{functionName}}().", | |
| data: { | |
| radixName, | |
| functionName: sourceCode.getText(node.callee) | |
| }, | |
| fix(fixer) { | |
| if (sourceCode.getCommentsInside(node).length) { | |
| return null; | |
| } | |
| const replacement = `${prefixMap[node.arguments[1].value]}${node.arguments[0].value}`; | |
| if (+replacement !== parseInt(node.arguments[0].value, node.arguments[1].value)) { | |
| /* | |
| * 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. | |
| */ | |
| 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}`); | |
| } | |
| }); | |
| } | |
| } | |
| }; | |
| } | |
| }; |