some tests

ntrack/listener_test.go

@@ -0,0 +1,82 @@
+package ntrack
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opencensus.io/stats/view"
+)
+
+func TestListener(t *testing.T) {
+
+	var tests = []struct {
+		viewName         string
+		disableKeepalive bool
+		expectedValue    int64
+	}{
+		{
+			viewName:         "ntrack/listener/accepts",
+			disableKeepalive: true,
+			expectedValue:    5,
+		},
+		{
+			viewName:         "ntrack/listener/accepts",
+			disableKeepalive: false,
+			expectedValue:    1,
+		},
+		{
+			viewName:         "ntrack/listener/closed",
+			disableKeepalive: true,
+			expectedValue:    5,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.viewName, func(t *testing.T) {
+			lis, err := net.Listen("tcp", "127.0.0.1:0")
+			require.NoError(t, err)
+
+			ilis, stats := NewInstrumentedListener(lis)
+			view.Register(stats.views...)
+
+			testClientConnections(t, ilis, tt.disableKeepalive)
+
+			rows, err := view.RetrieveData(tt.viewName)
+			require.NoError(t, err)
+			data := rows[0].Data.(*view.CountData)
+			assert.Equal(t, tt.expectedValue, data.Value)
+			view.Unregister(stats.views...)
+		})
+	}
+}
+
+func testClientConnections(t *testing.T, lis net.Listener, disableKeepalive bool) {
+	t.Helper()
+
+	srv := &http.Server{
+		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		}),
+	}
+
+	go func() {
+		if err := srv.Serve(lis); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	tr := &http.Transport{DisableKeepAlives: disableKeepalive}
+	client := &http.Client{Transport: tr}
+
+	requestCount := 5
+	for i := 0; i < requestCount; i++ {
+		resp, err := client.Get(fmt.Sprintf("http://%s", lis.Addr()))
+		require.NoError(t, err)
+		resp.Body.Close()
+	}
+
+}