63 lines
1.9 KiB
JavaScript
63 lines
1.9 KiB
JavaScript
|
/**
|
||
|
|
* @fileoverview Rule to flag the use of empty character classes in regular expressions
|
||
|
|
* @author Ian Christian Myers
|
||
|
|
*/
|
||
|
|
|
||
|
|
"use strict";
|
||
|
|
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
// Helpers
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
|
||
|
|
/*
|
||
|
|
* plain-English description of the following regexp:
|
||
|
|
* 0. `^` fix the match at the beginning of the string
|
||
|
|
* 1. `\/`: the `/` that begins the regexp
|
||
|
|
* 2. `([^\\[]|\\.|\[([^\\\]]|\\.)+\])*`: regexp contents; 0 or more of the following
|
||
|
|
* 2.0. `[^\\[]`: any character that's not a `\` or a `[` (anything but escape sequences and character classes)
|
||
|
|
* 2.1. `\\.`: an escape sequence
|
||
|
|
* 2.2. `\[([^\\\]]|\\.)+\]`: a character class that isn't empty
|
||
|
|
* 3. `\/` the `/` that ends the regexp
|
||
|
|
* 4. `[gimuy]*`: optional regexp flags
|
||
|
|
* 5. `$`: fix the match at the end of the string
|
||
|
|
*/
|
||
|
|
const regex = /^\/([^\\[]|\\.|\[([^\\\]]|\\.)+])*\/[gimuys]*$/;
|
||
|
|
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
// Rule Definition
|
||
|
|
//------------------------------------------------------------------------------
|
||
|
|
|
||
|
|
module.exports = {
|
||
|
|
meta: {
|
||
|
|
docs: {
|
||
|
|
description: "disallow empty character classes in regular expressions",
|
||
|
|
category: "Possible Errors",
|
||
|
|
recommended: true,
|
||
|
|
url: "https://eslint.org/docs/rules/no-empty-character-class"
|
||
|
|
},
|
||
|
|
|
||
|
|
schema: [],
|
||
|
|
|
||
|
|
messages: {
|
||
|
|
unexpected: "Empty class."
|
||
|
|
}
|
||
|
|
},
|
||
|
|
|
||
|
|
create(context) {
|
||
|
|
const sourceCode = context.getSourceCode();
|
||
|
|
|
||
|
|
return {
|
||
|
|
|
||
|
|
Literal(node) {
|
||
|
|
const token = sourceCode.getFirstToken(node);
|
||
|
|
|
||
|
|
if (token.type === "RegularExpression" && !regex.test(token.value)) {
|
||
|
|
context.report({ node, messageId: "unexpected" });
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
};
|
||
|
|
|
||
|
|
}
|
||
|
|
};
|