• Closes Support URLPattern as request predicate #1921
• Fixes Using the wildcard token to try to match random ports doesn't work if preceded by a colon #2204

This also significantly improves the test coverage for path matching in MSW.

This change does not intend to support URLPattern as the input. For now, we will use it as internal mechanism (thus a polyfill version). Once the API gains global browser support, we may consider shipping an input support.

Changes to document

• Multiple named groups are not supported: /:a/foo/:a. Not a thing in the HTTP spec. They are supported by path-to-regexp but URLPattern decided not to implement them and stick closer to the spec.
• Trailing slashes matter now. A /foo handler will not match a /foo/ request, and vice versa. I think MSW should respect that URLPattern behavior too to bring wider adoption of the API and be spec-compliant.

Roadmap

• /foo/:a/bar/:a syntax throws in URLPattern. Multiple same-named groups within the same URL component whatwg/urlpattern#226. Doesn't throw in path-to-regexp and current MSW. Don't want to make a breaking change out of this.
  • Dropping this promise.
• Support encoding since URLPattern doesn't.
  • Tests introduced in Decode path components in "req.params" #980 are passing as-is.