no-misleading-character-class

不允许在字符类语法中使用多个代码点组成的字符

Unicode 包括由多个代码点组成的字符。RegExp 字符类语法 (/[abc]/) 无法处理由多个代码点构成的字符作为一个字符；这些字符将被分解到每个代码点。例如，❇️ 由 ❇ (U+2747) 和 VARIATION SELECTOR-16 (U+FE0F) 制成。如果此字符属于 RegExp 字符类，它将匹配 ❇ (U+2747) 或 VARIATION SELECTOR-16 (U+FE0F)，而不是 ❇️。

¥Unicode includes characters which are made by multiple code points. 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 a RegExp character class, it will match either ❇ (U+2747) or VARIATION SELECTOR-16 (U+FE0F) rather than ❇️.

此规则报告在字符类语法中包含多个代码点字符的正则表达式。此规则将以下字符视为多个代码点字符。

¥This rule reports regular expressions which include multiple code point characters in character class syntax. This rule considers the following characters as multiple code point characters.

具有组合字符的字符：

¥A character with combining characters:

组合字符是属于 Mc、Me 和 Mn Unicode 常规类别 之一的字符。

¥The combining characters are characters which belong to one of Mc, Me, and Mn Unicode general categories.

/^[Á]$/u.test("Á"); //→ false
/^[❇️]$/u.test("❇️"); //→ false
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带有表情符号修饰符的角色：

¥A character with Emoji modifiers:

/^[👶🏻]$/u.test("👶🏻"); //→ false
/^[👶🏽]$/u.test("👶🏽"); //→ false
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一对区域指标符号：

¥A pair of regional indicator symbols:

/^[🇯🇵]$/u.test("🇯🇵"); //→ false
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ZWJ 加入的字符：

¥Characters that ZWJ joins:

/^[👨‍👩‍👦]$/u.test("👨‍👩‍👦"); //→ false
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没有 Unicode 标志的代理对：

¥A surrogate pair without Unicode flag:

/^[👍]$/.test("👍"); //→ false

// Surrogate pair is OK if with u flag.
/^[👍]$/u.test("👍"); //→ true
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规则详情

¥Rule Details

此规则报告在字符类语法中包含多个代码点字符的正则表达式。

¥This rule reports regular expressions which include multiple code point characters in character class syntax.

此规则的错误代码示例：

¥Examples of incorrect code for this rule:

/*eslint no-misleading-character-class: error */

/^[Á]$/u;
/^[❇️]$/u;
/^[👶🏻]$/u;
/^[🇯🇵]$/u;
/^[👨‍👩‍👦]$/u;
/^[👍]$/;
new RegExp("[🎵]");
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此规则的正确代码示例：

¥Examples of correct code for this rule:

/*eslint no-misleading-character-class: error */

/^[abc]$/;
/^[👍]$/u;
/^[\q{👶🏻}]$/v;
new RegExp("^[]$");
new RegExp(`[Á-${z}]`, "u"); // variable pattern
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选项

¥Options

此规则有一个对象选项：

¥This rule has an object option:

• "allowEscape"：当设置为 true 时，该规则允许字符类内的任何代码点分组，只要它们是使用转义序列编写的。此选项仅对正则表达式字面量和使用 RegExp 构造函数以字面量参数作为模式创建的正则表达式有效。

  ¥"allowEscape": When set to true, the rule allows any grouping of code points inside a character class as long as they are written using escape sequences. This option only has effect on regular expression literals and on regular expressions created with the RegExp constructor with a literal argument as a pattern.

allowEscape

使用 { "allowEscape": true } 选项的此规则的错误代码示例：

¥Examples of incorrect code for this rule with the { "allowEscape": true } option:

/* eslint no-misleading-character-class: ["error", { "allowEscape": true }] */

/[\👍]/; // backslash can be omitted

new RegExp("[\ud83d" + "\udc4d]");

const pattern = "[\ud83d\udc4d]";
new RegExp(pattern);
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使用 { "allowEscape": true } 选项的此规则的正确代码示例：

¥Examples of correct code for this rule with the { "allowEscape": true } option:

/* eslint no-misleading-character-class: ["error", { "allowEscape": true }] */

/[\ud83d\udc4d]/;
/[\u00B7\u0300-\u036F]/u;
/[👨\u200d👩]/u;
new RegExp("[\x41\u0301]");
new RegExp(`[\u{1F1EF}\u{1F1F5}]`, "u");
new RegExp("[\\u{1F1EF}\\u{1F1F5}]", "u");
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何时不使用

¥When Not To Use It

如果你不想检查多个代码点字符的 RegExp 字符类语法，则可以关闭此规则。

¥You can turn this rule off if you don’t want to check RegExp character class syntax for multiple code point characters.

版本

此规则是在 ESLint v5.3.0 中引入。

资源

• 规则源码
• 测试源码