Function TestCaptureMetrics

capture_metrics_test.go:14–126

(t *testing.T)

)

func TestCaptureMetrics(t *testing.T) {
	// Some of the edge cases tested below cause the net/http pkg to log some
	// messages that add a lot of noise to the `go test -v` output, so we discard
	// the log here.
	log.SetOutput(io.Discard)
	defer log.SetOutput(os.Stderr)

	tests := []struct {
		Name         string
		Handler      http.Handler
		WantDuration time.Duration
		WantWritten  int64
		WantCode     int
		WantErr      string
	}{
		{
			Name:     "simple",
			Handler:  http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}),
			WantCode: http.StatusOK,
		},
		{
			Name: "headers and body",
			Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				w.WriteHeader(http.StatusBadRequest)
				w.WriteHeader(http.StatusNotFound)
				w.Write([]byte("foo"))
				w.Write([]byte("bar"))
				time.Sleep(25 * time.Millisecond)
			}),
			WantCode:     http.StatusBadRequest,
			WantWritten:  6,
			WantDuration: 25 * time.Millisecond,
		},
		{
			Name: "header after body",
			Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				w.Write([]byte("foo"))
				w.WriteHeader(http.StatusNotFound)
			}),
			WantCode: http.StatusOK,
		},
		{
			Name: "reader",
			Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				rrf := w.(io.ReaderFrom)
				rrf.ReadFrom(strings.NewReader("reader from is ok"))
			}),
			WantWritten: 17,
			WantCode:    http.StatusOK,
		},
		{
			Name: "string writer",
			Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				_, _ = io.WriteString(w, "write string")
			}),
			WantWritten: int64(len("write string")),
			WantCode:    http.StatusOK,
		},