How to get params without route context?

[gpopovic]

Is it possible to get param from the handler without route context?

When i'm testing handler, i need to be able to retrieve params with chi.URLParam(), but when i try to do it outside router, i'm getting panic

[pkieltyka]

@gpopovic can you show me the test code for that handler?

it's possible to go about it a few ways, but if you're testing just a single handler that is trying to fetch URLParams from a request, then you need to make sure the URLParams object is available on the request chain. Have a look at https://github.com/pressly/chi/blob/master/mux_test.go#L810-L829

[gpopovic]

@pkieltyka exactly what i needed. Thanks

[christopherdiehl]

@pkieltyka can you please elaborate? I don't understand how to replicate the URLParams in the router context.

Thank you!

[soedar]

I've recently ran into the same issue. For posterity, this should work:

w := httptest.NewRecorder()
r := httptest.NewRequest("GET", "/", nil)

rctx := chi.NewRouteContext()
rctx.URLParams.Add("key", "value")

r = r.WithContext(context.WithValue(r.Context(), chi.RouteCtxKey, rctx))

handler := func(w http.ResponseWriter, r *http.Request) {
	key := chi.URLParam(r, "key") // "value"
}
handler(w, r)

Adapted from:

chi/mux_test.go

Lines 1143 to 1145 in 91a3777

	rctx := NewRouteContext()
	r = r.WithContext(context.WithValue(r.Context(), RouteCtxKey, rctx))
	rctx.URLParams.Add("name", "joe")

[gonzaloserrano]

@soedar solution works, thanks a lot!

Anyway I don't think chi should panic if the context is not available like it does with:

panic: interface conversion: interface {} is nil, not *chi.Context [recovered]
	panic: interface conversion: interface {} is nil, not *chi.Context

Maybe if there is no context URLParam() could return empty string instead?