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Diffstat (limited to 'tools/node_modules/eslint/lib/rules/prefer-numeric-literals.js')
-rw-r--r-- | tools/node_modules/eslint/lib/rules/prefer-numeric-literals.js | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/prefer-numeric-literals.js b/tools/node_modules/eslint/lib/rules/prefer-numeric-literals.js new file mode 100644 index 0000000000..929e660c66 --- /dev/null +++ b/tools/node_modules/eslint/lib/rules/prefer-numeric-literals.js @@ -0,0 +1,112 @@ +/** + * @fileoverview Rule to disallow `parseInt()` in favor of binary, octal, and hexadecimal literals + * @author Annie Zhang, Henry Zhu + */ + +"use strict"; + +//------------------------------------------------------------------------------ +// 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: { + docs: { + description: "disallow `parseInt()` and `Number.parseInt()` in favor of binary, octal, and hexadecimal literals", + category: "ECMAScript 6", + recommended: false + }, + + 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) { + const newPrefix = prefixMap[node.arguments[1].value]; + + if (+(newPrefix + node.arguments[0].value) !== 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; + } + return fixer.replaceText(node, prefixMap[node.arguments[1].value] + node.arguments[0].value); + } + }); + } + } + }; + } +}; |