prefer-regex-literals
禁止使用 RegExp 构造函数以支持正则表达式字面
此规则报告的一些问题可通过编辑器建议手动修复
创建正则表达式有两种方法：
¥There are two ways to create a regular expression:
-
正则表达式字面，例如
/abc/u。¥Regular expression literals, e.g.,
/abc/u. -
RegExp构造函数，例如new RegExp("abc", "u")或RegExp("abc", "u")。¥The
RegExpconstructor function, e.g.,new RegExp("abc", "u")orRegExp("abc", "u").
当你想要动态生成模式时，构造函数特别有用，因为它接受字符串参数。
¥The constructor function is particularly useful when you want to dynamically generate the pattern, because it takes string arguments.
当使用带有字符串字面的构造函数时，不要忘记字符串转义规则仍然适用。如果要在模式中放置反斜杠，则需要在字符串字面中对其进行转义。因此，以下是等价的：
¥When using the constructor function with string literals, don’t forget that the string escaping rules still apply. If you want to put a backslash in the pattern, you need to escape it in the string literal. Thus, the following are equivalent:
new RegExp("^\\d\\.$");
/^\d\.$/;
// matches "0.", "1.", "2." ... "9."
在上面的示例中，正则表达式字面更易于阅读和推断。此外，在字符串字面中省略额外的 \ 是一个常见错误，这会产生完全不同的正则表达式：
¥In the above example, the regular expression literal is easier to read and reason about.
Also, it’s a common mistake to omit the extra \ in the string literal, which would produce a completely different regular expression:
new RegExp("^\d\.$");
// equivalent to /^d.$/, matches "d1", "d2", "da", "db" ...
当预先知道正则表达式时，最好避免在正则表达式表示法之上使用字符串字面表示法，并使用正则表达式字面而不是构造函数。
¥When a regular expression is known in advance, it is considered a best practice to avoid the string literal notation on top of the regular expression notation, and use regular expression literals instead of the constructor function.
规则详情
¥Rule Details
此规则不允许使用 RegExp 构造函数并将字符串字面作为其参数。
¥This rule disallows the use of the RegExp constructor function with string literals as its arguments.
此规则还禁止将 RegExp 构造函数与不带表达式的模板字面和不带表达式的 String.raw 标记模板字面一起使用。
¥This rule also disallows the use of the RegExp constructor function with template literals without expressions
and String.raw tagged template literals without expressions.
该规则并不禁止所有使用 RegExp 构造函数。它仍应用于动态生成的正则表达式。
¥The rule does not disallow all use of the RegExp constructor. It should be still used for
dynamically generated regular expressions.
此规则的错误代码示例：
¥Examples of incorrect code for this rule:
/*eslint prefer-regex-literals: "error"*/
new RegExp("abc");
new RegExp("abc", "u");
RegExp("abc");
RegExp("abc", "u");
new RegExp("\\d\\d\\.\\d\\d\\.\\d\\d\\d\\d");
RegExp(`^\\d\\.$`);
new RegExp(String.raw`^\d\.$`);
此规则的正确代码示例：
¥Examples of correct code for this rule:
/*eslint prefer-regex-literals: "error"*/
/abc/;
/abc/u;
/\d\d\.\d\d\.\d\d\d\d/;
/^\d\.$/;
// RegExp constructor is allowed for dynamically generated regular expressions
new RegExp(pattern);
RegExp("abc", flags);
new RegExp(prefix + "abc");
RegExp(`${prefix}abc`);
new RegExp(String.raw`^\d\. ${suffix}`);
选项
¥Options
此规则有一个对象选项：
¥This rule has an object option:
-
disallowRedundantWrapping设置为true额外检查不必要的封装正则表达式字面（默认false）。¥
disallowRedundantWrappingset totrueadditionally checks for unnecessarily wrapped regex literals (Defaultfalse).
disallowRedundantWrapping
默认情况下，当正则表达式字面不必要地封装在 RegExp 构造函数调用中时，此规则不会检查。When the option disallowRedundantWrapping is set to true, the rule will also disallow such unnecessary patterns.
¥By default, this rule doesn’t check when a regex literal is unnecessarily wrapped in a RegExp constructor call. When the option disallowRedundantWrapping is set to true, the rule will also disallow such unnecessary patterns.
{ "disallowRedundantWrapping": true } 的 incorrect 代码示例
¥Examples of incorrect code for { "disallowRedundantWrapping": true }
/*eslint prefer-regex-literals: ["error", {"disallowRedundantWrapping": true}]*/
new RegExp(/abc/);
new RegExp(/abc/, 'u');
{ "disallowRedundantWrapping": true } 的 correct 代码示例
¥Examples of correct code for { "disallowRedundantWrapping": true }
/*eslint prefer-regex-literals: ["error", {"disallowRedundantWrapping": true}]*/
/abc/;
/abc/u;
new RegExp(/abc/, flags);
版本
此规则是在 ESLint v6.4.0 中引入。