Invalid prop path of type regexp supplied to Route, expected string

[Fi1osof]

Version

PropTypes require String or [String] for Route, but Route allow use regex too.

Test Case

https://codesandbox.io/s/yv2z0x7qo1 (See route for topics).

Expected Behavior

No warnings.
Allow types: String, RegExp, [String, RegExp]

Actual Behavior

Warning: Failed prop type: Invalid prop path of type regexp supplied to Route, expected string.
in Route

react-router-dom@4.3.1

[timdorr]

Regex isn't allowed in the path. We cache our generated regexps, so this would break that.

[Fi1osof]

@timdorr, so this is undocumented features. And it should be allowed. Because it works. Have a look: https://codesandbox.io/s/yv2z0x7qo1
I switch URLs /topics/topic-234.html and /topics/topic-CharID.html and got 234 and CharID in separated components. Switch component uses regexp https://github.com/ReactTraining/react-router/blob/master/packages/react-router/modules/matchPath.js#L42

[pshrmn]

It may technically work, but it shouldn't be encouraged.

path-to-regexp (what React Router uses for path matching) supports custom match parameters if you want to only match specific content in a segment.

Using a RegExp path can also cause issues. What happens if you want to nest a route as a child of a route whose path is a RegExp? With strings you can grab match.path and concatenate, but there is no simple way to join regular expressions.

[Fi1osof]

@pshrmn, thank you for the clarification. OK.

[kevich]

I think technically there is no problem to convert RegExp to strings on react-router level, so that it will behave pretty the same as now. Even concatenating is ok, since even now there is kind of support RegExp in stings with custom match parameters, and it will be the same issue either with text with RegExp or real RegExp. So it should be up to developer not to shoot into his own leg with that concatenations.

Still my point is if react-router uses path-to-regexp, it should support all of it's features.

But for what it's really needed to be supported as RegExp by react-router is because of this issue in pillarjs/path-to-regexp#99. And for now there is no other way to use (?!something) than using it as RegExp