Reviving this [thread] a third time, is there any love left for introducing
RegExp.escape? The previous attempt was abandoned because of a so-called
"[even-odd problem]", but that can be fixed: backslash-escape every
_SyntaxCharacter_, then wrap the full result in a new form of non-capturing
group that is only valid **as a unit** (and therefore protected from otherwise
dangerous preceding fragments). For example, `(?](?)â¦)` is a good candidate
because preceding such content with a right bracket (starting a
_CharacterClass_) and/or a backslash (escaping special treatment of the initial
parenthesis) would produce invalid syntax by exposing the "(?)".
As a result, `new RegExp(RegExp.escape("foo.bar"))` is valid (i.e.,
`/(?](?)foo\.bar)/`, equivalent in evaluation to `/(?:foo\.bar)/`) but `new
RegExp("\\" + RegExp.escape("foo.bar"))` and even `new RegExp("([\\" +
RegExp.escape("foo.bar"))` would throw SyntaxErrors.
The upside of such a change is getting safe access to desired language
functionality. The downside, of course, is the new pattern's supreme ugliness.
Sample polyfill:
```
const regExpSyntaxCharacter = /[\^$\\.*+?()[\]{}|]/g;
RegExp.escape = function( value ) {
return "(?](?)" + (value + "").replace(regExpSyntaxCharacter, "\\$&") +
")";
}
```
[thread]: https://esdiscuss.org/topic/regexp-escape
[even-odd problem]: https://github.com/benjamingr/RegExp.escape/issues/37
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