projects / pve-eslint.git / blame
| Commit | Line | Data |
|---|---|---|
| eb39fafa DC |
1 | # Disallow characters which are made with multiple code points in character class syntax (no-misleading-character-class) |
| 2 | ||
| 3 | Unicode includes the characters which are made with multiple code points. | |
| 4 | RegExp character class syntax (`/[abc]/`) cannot handle characters which are made by multiple code points as a character; those characters will be dissolved to each code point. For example, `❇️` is made by `❇` (`U+2747`) and VARIATION SELECTOR-16 (`U+FE0F`). If this character is in RegExp character class, it will match to either `❇` (`U+2747`) or VARIATION SELECTOR-16 (`U+FE0F`) rather than `❇️`. | |
| 5 | ||
| 6 | This rule reports the regular expressions which include multiple code point characters in character class syntax. This rule considers the following characters as multiple code point characters. | |
| 7 | ||
| 8 | **A character with combining characters:** | |
| 9 | ||
| 10 | The combining characters are characters which belong to one of `Mc`, `Me`, and `Mn` [Unicode general categories](http://www.unicode.org/L2/L1999/UnicodeData.html#General%20Category). | |
| 11 | ||
| 12 | ```js | |
| 13 | /^[Á]$/u.test("Á") //→ false | |
| 14 | /^[❇️]$/u.test("❇️") //→ false | |
| 15 | ``` | |
| 16 | ||
| 17 | **A character with Emoji modifiers:** | |
| 18 | ||
| 19 | ```js | |
| 20 | /^[👶🏻]$/u.test("👶🏻") //→ false | |
| 21 | /^[👶🏽]$/u.test("👶🏽") //→ false | |
| 22 | ``` | |
| 23 | ||
| 24 | **A pair of regional indicator symbols:** | |
| 25 | ||
| 26 | ```js | |
| 27 | /^[🇯🇵]$/u.test("🇯🇵") //→ false | |
| 28 | ``` | |
| 29 | ||
| 30 | **Characters that ZWJ joins:** | |
| 31 | ||
| 32 | ```js | |
| 33 | /^[👨👩👦]$/u.test("👨👩👦") //→ false | |
| 34 | ``` | |
| 35 | ||
| 36 | **A surrogate pair without Unicode flag:** | |
| 37 | ||
| 38 | ```js | |
| 39 | /^[👍]$/.test("👍") //→ false | |
| 40 | ||
| 41 | // Surrogate pair is OK if with u flag. | |
| 42 | /^[👍]$/u.test("👍") //→ true | |
| 43 | ``` | |
| 44 | ||
| 45 | ## Rule Details | |
| 46 | ||
| 47 | This rule reports the regular expressions which include multiple code point characters in character class syntax. | |
| 48 | ||
| 49 | Examples of **incorrect** code for this rule: | |
| 50 | ||
| 51 | ```js | |
| 52 | /*eslint no-misleading-character-class: error */ | |
| 53 | ||
| 54 | /^[Á]$/u | |
| 55 | /^[❇️]$/u | |
| 56 | /^[👶🏻]$/u | |
| 57 | /^[🇯🇵]$/u | |
| 58 | /^[👨👩👦]$/u | |
| 59 | /^[👍]$/ | |
| 60 | ``` | |
| 61 | ||
| 62 | Examples of **correct** code for this rule: | |
| 63 | ||
| 64 | ```js | |
| 65 | /*eslint no-misleading-character-class: error */ | |
| 66 | ||
| 67 | /^[abc]$/ | |
| 68 | /^[👍]$/u | |
| 69 | ``` | |
| 70 | ||
| 71 | ## When Not To Use It | |
| 72 | ||
| 73 | You can turn this rule off if you don't want to check RegExp character class syntax for multiple code point characters. |