Regex param doesn't match dots

[Nyoroon]

Example program:

package main

import (
	"fmt"
	"net/http"
	"net/http/httptest"

	"github.com/go-chi/chi/v5"
)

func main() {
	mux := chi.NewMux()
	mux.Get("/{param:.+}.json", func(w http.ResponseWriter, r *http.Request) {
		param := chi.URLParam(r, "param")
		_, _ = fmt.Fprintf(w, "param=%s", param)
	})

	rec := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/param.json", nil)
	mux.ServeHTTP(rec, req)

	fmt.Printf("code: %d, body: %s\n", rec.Code, rec.Body)

	rec = httptest.NewRecorder()
	req = httptest.NewRequest(http.MethodGet, "/param.with.dots.json", nil)
	mux.ServeHTTP(rec, req)

	fmt.Printf("code: %d, body: %s\n", rec.Code, rec.Body)
}

Expected:

code: 200, body: param=param
code: 404, body: param=param.with.dots

Got:

code: 200, body: param=param
code: 404, body: 404 page not found

[samsapti]

@Nyoroon the . in regex means "any character", so if you want to match a literal ., you need to escape it. Your string would then be: "/{param:\\.+}.json".

[Nyoroon]

@Nyoroon the . in regex means "any character", so if you want to match a literal ., you need to escape it. Your string would then be: "/{param:\\.+}.json".

Yeah, and I want to match "any character", but it matches "any character except dot". I have an example in post.

[samsapti]

Okay, have you tried "/{param:[.\\.]+}.json"?

[js-everts]

@Nyoroon

This is not really a problem with the regex, it fails due to ambiguity.

If you were to modify the param to "/{param:.+}:json" (note the colon, it can be anything else) then make the request /param.with.dots:json, this will work because there is no ambiguity, chi knows everything before the colon (:) is supposed to be the param.

I suggest you define a the route like this r.Get("/{param:.+\\.json}", ...), then strip out and process the param manually in your handler.

[6543]

#811 only fix things partially ... see #813 but at lest it's a move in the right direction ...