feat: edge gateway service

gateway/internal/push/hub_observability_test.go

@@ -0,0 +1,77 @@
+package push_test
+
+import (
+	"testing"
+	"time"
+
+	"galaxy/gateway/internal/push"
+	"galaxy/gateway/internal/telemetry"
+	"galaxy/gateway/internal/testutil"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestHubObserverClassifiesClosureReasons(t *testing.T) {
+	t.Parallel()
+
+	logger, _ := testutil.NewObservedLogger(t)
+	telemetryRuntime := testutil.NewTelemetryRuntime(t, logger)
+	hub := push.NewHubWithObserver(1, telemetry.NewPushObserver(telemetryRuntime))
+
+	overflow, err := hub.Register(push.StreamBinding{
+		UserID:          "user-123",
+		DeviceSessionID: "device-session-overflow",
+	})
+	require.NoError(t, err)
+	revoked, err := hub.Register(push.StreamBinding{
+		UserID:          "user-123",
+		DeviceSessionID: "device-session-revoked",
+	})
+	require.NoError(t, err)
+	shutdown, err := hub.Register(push.StreamBinding{
+		UserID:          "user-123",
+		DeviceSessionID: "device-session-shutdown",
+	})
+	require.NoError(t, err)
+
+	hub.Publish(push.Event{
+		UserID:          "user-123",
+		DeviceSessionID: "device-session-overflow",
+		EventType:       "fleet.updated",
+		EventID:         "event-1",
+		PayloadBytes:    []byte("payload-1"),
+	})
+	hub.Publish(push.Event{
+		UserID:          "user-123",
+		DeviceSessionID: "device-session-overflow",
+		EventType:       "fleet.updated",
+		EventID:         "event-2",
+		PayloadBytes:    []byte("payload-2"),
+	})
+	hub.RevokeDeviceSession("device-session-revoked")
+	hub.Shutdown()
+
+	select {
+	case <-overflow.Done():
+	case <-time.After(time.Second):
+		require.FailNow(t, "overflow subscription did not close")
+	}
+	select {
+	case <-revoked.Done():
+	case <-time.After(time.Second):
+		require.FailNow(t, "revoked subscription did not close")
+	}
+	select {
+	case <-shutdown.Done():
+	case <-time.After(time.Second):
+		require.FailNow(t, "shutdown subscription did not close")
+	}
+
+	metricsText := testutil.ScrapeMetrics(t, telemetryRuntime.Handler())
+	assert.Contains(t, metricsText, `gateway_push_stream_closures_total`)
+	assert.Contains(t, metricsText, `reason="overflow"`)
+	assert.Contains(t, metricsText, `reason="revoked"`)
+	assert.Contains(t, metricsText, `reason="shutdown"`)
+	assert.Contains(t, metricsText, `gateway_push_active_streams`)
+}