Unable to see the vars when calling from a unit test

[swalberg]

What version of Go are you running? go version go1.10.2 darwin/amd64

What version of gorilla/mux are you at? 5e55a4a

Describe your problem (and what you have tried so far)

I'm trying to test a route with a path variable but the handler sees an empty map when called from a unit test. It works fine with cURL against a running instance.

Paste a minimal, runnable, reproduction of your issue below (use backticks to format it)
I have slightly altered the example from the README.

package main

import (
	"fmt"
	"github.com/gorilla/mux"
	"log"
	"net/http"
)

func main() {
	r := mux.NewRouter()
	r.HandleFunc("/metrics/{type}", MetricsHandler)

	log.Fatal(http.ListenAndServe("localhost:8080", r))
}

func MetricsHandler(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	w.Header().Set("Content-Type", "application/json")

	vars := mux.Vars(r)
	w.WriteHeader(http.StatusOK)
	fmt.Fprintf(w, "Type: %v", vars["type"])
}

package main

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

func TestMetricsHandler(t *testing.T) {
	tt := []struct {
		routeVariable string
		shouldPass    bool
	}{
		{"goroutines", true},
		{"heap", true},
		{"counters", true},
		{"queries", true},
		{"adhadaeqm3k", false},
	}

	for _, tc := range tt {
		path := fmt.Sprintf("/metrics/%s", tc.routeVariable)
		req, err := http.NewRequest("GET", path, nil)
		if err != nil {
			t.Fatal(err)
		}

		rr := httptest.NewRecorder()
		handler := http.HandlerFunc(MetricsHandler)
		handler.ServeHTTP(rr, req)

		expected := fmt.Sprintf("Type: %v", tc.routeVariable)

		if rr.Body.String() != expected {
			t.Errorf("handler should have failed on routeVariable %s: got %v want %v",
				tc.routeVariable, rr.Body.String(), expected)
		}
	}
}

sean~/go/src/gitlab.com/swalberg/muxtest$ go test *
--- FAIL: TestMetricsHandler (0.00s)
	endpoints_test.go:36: handler should have failed on routeVariable goroutines: got Type:  want Type: goroutines
	endpoints_test.go:36: handler should have failed on routeVariable heap: got Type:  want Type: heap
	endpoints_test.go:36: handler should have failed on routeVariable counters: got Type:  want Type: counters
	endpoints_test.go:36: handler should have failed on routeVariable queries: got Type:  want Type: queries
	endpoints_test.go:36: handler should have failed on routeVariable adhadaeqm3k: got Type:  want Type: adhadaeqm3k
FAIL
FAIL	command-line-arguments	0.014s

[swalberg]

Been trying this out with a few different versions of gorilla/mux as far back as 94903de and none of them work with this. Am I doing something incorrectly? Possibly a dupe of #342?

[swalberg]

I changed my tests to set the vars directly like in #342 and it passes:

package main

import (
	"fmt"
	"github.com/gorilla/mux"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestMetricsHandler(t *testing.T) {
	tt := []struct {
		routeVariable string
		shouldPass    bool
	}{
		{"goroutines", true},
		{"heap", true},
		{"counters", true},
		{"queries", true},
		{"adhadaeqm3k", false},
	}

	for _, tc := range tt {
		path := "whocares"
		req, err := http.NewRequest("GET", path, nil)
		if err != nil {
			t.Fatal(err)
		}
		req = mux.SetURLVars(req, map[string]string{
			"type": tc.routeVariable,
		})
		rr := httptest.NewRecorder()
		/* Appears we can call it directly if we want?
			handler := http.HandlerFunc(MetricsHandler)
			handler.ServeHTTP(rr, req)*/
		MetricsHandler(rr, req)

		expected := fmt.Sprintf("Type: %v", tc.routeVariable)

		if rr.Body.String() != expected {
			t.Errorf("handler should have failed on routeVariable %s: got %v want %v",
				tc.routeVariable, rr.Body.String(), expected)
		}
	}
}

Can you elaborate on comments in #342? My understanding is "yes you can use mux.SetURLVars but you should really do it the way I've shown" which I prefer, but can't get to work.

Thanks!

[kisielk]

I’m just reading this off my phone so I could be wrong, but it seems in your test you never actually instantiate a mux, you’re just hanging the handler off the http recorder.

…

On May 12, 2018, at 10:04, Sean Walberg ***@***.***> wrote: I changed my tests to set the vars directly like in #342 and it passes: package main import ( "fmt" "github.com/gorilla/mux" "net/http" "net/http/httptest" "testing" ) func TestMetricsHandler(t *testing.T) { tt := []struct { routeVariable string shouldPass bool }{ {"goroutines", true}, {"heap", true}, {"counters", true}, {"queries", true}, {"adhadaeqm3k", false}, } for _, tc := range tt { path := "whocares" req, err := http.NewRequest("GET", path, nil) if err != nil { t.Fatal(err) } req = mux.SetURLVars(req, map[string]string{ "type": tc.routeVariable, }) rr := httptest.NewRecorder() /* Appears we can call it directly if we want? handler := http.HandlerFunc(MetricsHandler) handler.ServeHTTP(rr, req)*/ MetricsHandler(rr, req) expected := fmt.Sprintf("Type: %v", tc.routeVariable) if rr.Body.String() != expected { t.Errorf("handler should have failed on routeVariable %s: got %v want %v", tc.routeVariable, rr.Body.String(), expected) } } } Can you elaborate on comments in #342? My understanding is "yes you can use mux.SetURLVars but you should really do it the way I've shown" which I prefer, but can't get to work. Thanks! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or mute the thread.

[elithrar]

Mirrors what I’m seeing. mux.SetURLVars uses the request context directly, and thus doesn’t rely on a Router instance. The URL parsing into vars does (as expected) require a Router instance. On Sat, May 12, 2018 at 11:57 AM Kamil Kisiel <notifications@github.com> wrote:

…

I’m just reading this off my phone so I could be wrong, but it seems in your test you never actually instantiate a mux, you’re just hanging the handler off the http recorder. > On May 12, 2018, at 10:04, Sean Walberg ***@***.***> wrote: > > I changed my tests to set the vars directly like in #342 and it passes: > > package main > > import ( > "fmt" > "github.com/gorilla/mux" > "net/http" > "net/http/httptest" > "testing" > ) > > func TestMetricsHandler(t *testing.T) { > tt := []struct { > routeVariable string > shouldPass bool > }{ > {"goroutines", true}, > {"heap", true}, > {"counters", true}, > {"queries", true}, > {"adhadaeqm3k", false}, > } > > for _, tc := range tt { > path := "whocares" > req, err := http.NewRequest("GET", path, nil) > if err != nil { > t.Fatal(err) > } > req = mux.SetURLVars(req, map[string]string{ > "type": tc.routeVariable, > }) > rr := httptest.NewRecorder() > /* Appears we can call it directly if we want? > handler := http.HandlerFunc(MetricsHandler) > handler.ServeHTTP(rr, req)*/ > MetricsHandler(rr, req) > > expected := fmt.Sprintf("Type: %v", tc.routeVariable) > > if rr.Body.String() != expected { > t.Errorf("handler should have failed on routeVariable %s: got %v want %v", > tc.routeVariable, rr.Body.String(), expected) > } > } > } > Can you elaborate on comments in #342? My understanding is "yes you can use mux.SetURLVars but you should really do it the way I've shown" which I prefer, but can't get to work. > > Thanks! > > — > You are receiving this because you are subscribed to this thread. > Reply to this email directly, view it on GitHub, or mute the thread. > — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#373 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AABIcOws8EcHTZQ7EWvl11cBOIFBWC9aks5txzB9gaJpZM4T8cnN> .

[swalberg]

OK, thanks @elithrar and @kisielk, that was enough to get me to something working. I've made a PR to fix the docs to reflect our discussion. If that's still not the right way please let me know and I'll be happy to fix!

Sean

[Guilhermeslucas]

@swalberg Thanks a lot for your response, man. Your help fixed the problem I was having the whole afternoon. Thanks a lot!