114 lines
3.7 KiB
JavaScript
114 lines
3.7 KiB
JavaScript
/**
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* @fileoverview Rule to disallow `parseInt()` in favor of binary, octal, and hexadecimal literals
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* @author Annie Zhang, Henry Zhu
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*/
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"use strict";
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//------------------------------------------------------------------------------
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// Helpers
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//------------------------------------------------------------------------------
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/**
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* Checks to see if a CallExpression's callee node is `parseInt` or
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* `Number.parseInt`.
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* @param {ASTNode} calleeNode The callee node to evaluate.
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* @returns {boolean} True if the callee is `parseInt` or `Number.parseInt`,
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* false otherwise.
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*/
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function isParseInt(calleeNode) {
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switch (calleeNode.type) {
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case "Identifier":
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return calleeNode.name === "parseInt";
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case "MemberExpression":
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return calleeNode.object.type === "Identifier" &&
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calleeNode.object.name === "Number" &&
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calleeNode.property.type === "Identifier" &&
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calleeNode.property.name === "parseInt";
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// no default
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}
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return false;
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}
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//------------------------------------------------------------------------------
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// Rule Definition
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//------------------------------------------------------------------------------
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module.exports = {
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meta: {
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docs: {
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description: "disallow `parseInt()` and `Number.parseInt()` in favor of binary, octal, and hexadecimal literals",
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category: "ECMAScript 6",
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recommended: false,
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url: "https://eslint.org/docs/rules/prefer-numeric-literals"
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},
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schema: [],
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fixable: "code"
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},
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create(context) {
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const sourceCode = context.getSourceCode();
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const radixMap = {
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2: "binary",
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8: "octal",
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16: "hexadecimal"
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};
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const prefixMap = {
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2: "0b",
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8: "0o",
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16: "0x"
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};
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//----------------------------------------------------------------------
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// Public
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//----------------------------------------------------------------------
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return {
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CallExpression(node) {
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// doesn't check parseInt() if it doesn't have a radix argument
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if (node.arguments.length !== 2) {
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return;
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}
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// only error if the radix is 2, 8, or 16
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const radixName = radixMap[node.arguments[1].value];
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if (isParseInt(node.callee) &&
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radixName &&
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node.arguments[0].type === "Literal"
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) {
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context.report({
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node,
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message: "Use {{radixName}} literals instead of {{functionName}}().",
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data: {
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radixName,
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functionName: sourceCode.getText(node.callee)
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},
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fix(fixer) {
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const newPrefix = prefixMap[node.arguments[1].value];
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if (+(newPrefix + node.arguments[0].value) !== parseInt(node.arguments[0].value, node.arguments[1].value)) {
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/*
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* If the newly-produced literal would be invalid, (e.g. 0b1234),
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* or it would yield an incorrect parseInt result for some other reason, don't make a fix.
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*/
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return null;
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}
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return fixer.replaceText(node, prefixMap[node.arguments[1].value] + node.arguments[0].value);
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}
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});
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}
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}
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};
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}
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};
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