84 lines
1.9 KiB
JavaScript
84 lines
1.9 KiB
JavaScript
/**
|
|
* @fileoverview Rule to flag the use of empty character classes in regular expressions
|
|
* @author Ian Christian Myers
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Requirements
|
|
//------------------------------------------------------------------------------
|
|
|
|
const { RegExpParser, visitRegExpAST } = require("@eslint-community/regexpp");
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Helpers
|
|
//------------------------------------------------------------------------------
|
|
|
|
const parser = new RegExpParser();
|
|
const QUICK_TEST_REGEX = /\[\]/u;
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Rule Definition
|
|
//------------------------------------------------------------------------------
|
|
|
|
/** @type {import('../types').Rule.RuleModule} */
|
|
module.exports = {
|
|
meta: {
|
|
type: "problem",
|
|
|
|
docs: {
|
|
description:
|
|
"Disallow empty character classes in regular expressions",
|
|
recommended: true,
|
|
url: "https://eslint.org/docs/latest/rules/no-empty-character-class",
|
|
},
|
|
|
|
schema: [],
|
|
|
|
messages: {
|
|
unexpected: "Empty class.",
|
|
},
|
|
},
|
|
|
|
create(context) {
|
|
return {
|
|
"Literal[regex]"(node) {
|
|
const { pattern, flags } = node.regex;
|
|
|
|
if (!QUICK_TEST_REGEX.test(pattern)) {
|
|
return;
|
|
}
|
|
|
|
let regExpAST;
|
|
|
|
try {
|
|
regExpAST = parser.parsePattern(
|
|
pattern,
|
|
0,
|
|
pattern.length,
|
|
{
|
|
unicode: flags.includes("u"),
|
|
unicodeSets: flags.includes("v"),
|
|
},
|
|
);
|
|
} catch {
|
|
// Ignore regular expressions that regexpp cannot parse
|
|
return;
|
|
}
|
|
|
|
visitRegExpAST(regExpAST, {
|
|
onCharacterClassEnter(characterClass) {
|
|
if (
|
|
!characterClass.negate &&
|
|
characterClass.elements.length === 0
|
|
) {
|
|
context.report({ node, messageId: "unexpected" });
|
|
}
|
|
},
|
|
});
|
|
},
|
|
};
|
|
},
|
|
};
|