Route icon results through UI events (T-607)

core/application/event_relay_test.go

@@ -0,0 +1,208 @@
+package application
+
+import (
+	"context"
+	"errors"
+	"reflect"
+	"testing"
+	"time"
+)
+
+func TestEventRelayUsesBoundedFIFOBackpressure(t *testing.T) {
+	relay, err := NewEventRelay(1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	first := Event{Type: EventCatalogRefreshed, RequestID: "first"}
+	second := Event{Type: EventCatalogRejected, RequestID: "second"}
+	if err := relay.Submit(context.Background(), first); err != nil {
+		t.Fatal(err)
+	}
+
+	started := make(chan struct{})
+	secondResult := make(chan error, 1)
+	go func() {
+		close(started)
+		secondResult <- relay.Submit(context.Background(), second)
+	}()
+	<-started
+	select {
+	case err := <-secondResult:
+		t.Fatalf("second Submit() completed while relay was full: %v", err)
+	default:
+	}
+
+	var received []string
+	if err := relay.Drain(func(event Event) error {
+		received = append(received, event.RequestID)
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if err := waitRelayResult(secondResult); err != nil {
+		t.Fatalf("second Submit() error = %v", err)
+	}
+	if err := relay.Drain(func(event Event) error {
+		received = append(received, event.RequestID)
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(received, []string{"first", "second"}) {
+		t.Fatalf("received order = %v", received)
+	}
+}
+
+func TestEventRelayCloseAndContextUnblockFullSubmit(t *testing.T) {
+	tests := []struct {
+		name    string
+		unblock func(*EventRelay, context.CancelFunc)
+		wantErr error
+	}{
+		{
+			name: "close",
+			unblock: func(relay *EventRelay, _ context.CancelFunc) {
+				relay.Close()
+			},
+			wantErr: ErrEventRelayClosed,
+		},
+		{
+			name: "cancel",
+			unblock: func(_ *EventRelay, cancel context.CancelFunc) {
+				cancel()
+			},
+			wantErr: context.Canceled,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			relay, err := NewEventRelay(1)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if err := relay.Submit(
+				context.Background(),
+				Event{Type: EventCatalogRefreshed},
+			); err != nil {
+				t.Fatal(err)
+			}
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+			started := make(chan struct{})
+			result := make(chan error, 1)
+			go func() {
+				close(started)
+				result <- relay.Submit(ctx, Event{Type: EventCatalogRejected})
+			}()
+			<-started
+			test.unblock(relay, cancel)
+			if err := waitRelayResult(result); !errors.Is(err, test.wantErr) {
+				t.Fatalf("Submit() error = %v, want %v", err, test.wantErr)
+			}
+		})
+	}
+}
+
+func TestPumpEventsInvalidatesBeforeUIDrainAndStops(t *testing.T) {
+	relay, err := NewEventRelay(1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	source := make(chan Event, 2)
+	invalidated := make(chan struct{}, 2)
+	ctx, cancel := context.WithCancel(context.Background())
+	pumpResult := make(chan error, 1)
+	go func() {
+		pumpResult <- PumpEvents(ctx, source, relay, func() {
+			invalidated <- struct{}{}
+		})
+	}()
+
+	first := Event{Type: EventCatalogRefreshed, RequestID: "first"}
+	second := Event{Type: EventCatalogRejected, RequestID: "second"}
+	source <- first
+	source <- second
+	waitSignal(t, invalidated)
+
+	var received []string
+	if len(received) != 0 {
+		t.Fatal("background pump applied an event before UI drain")
+	}
+	if err := relay.Drain(func(event Event) error {
+		received = append(received, event.RequestID)
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+	waitSignal(t, invalidated)
+	if err := relay.Drain(func(event Event) error {
+		received = append(received, event.RequestID)
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(received, []string{"first", "second"}) {
+		t.Fatalf("received order = %v", received)
+	}
+
+	cancel()
+	if err := waitRelayResult(pumpResult); !errors.Is(err, context.Canceled) {
+		t.Fatalf("PumpEvents() error = %v", err)
+	}
+}
+
+func TestEventRelayDrainReportsErrorsAndContinues(t *testing.T) {
+	relay, err := NewEventRelay(2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, eventType := range []EventType{EventCatalogRefreshed, EventCatalogRejected} {
+		if err := relay.Submit(context.Background(), Event{Type: eventType}); err != nil {
+			t.Fatal(err)
+		}
+	}
+	wantErr := errors.New("apply failed")
+	applied := 0
+	err = relay.Drain(func(Event) error {
+		applied++
+		return wantErr
+	})
+	if !errors.Is(err, wantErr) || applied != 2 {
+		t.Fatalf("Drain() = (%d applies, %v)", applied, err)
+	}
+}
+
+func TestNewEventRelayRejectsInvalidCapacity(t *testing.T) {
+	if _, err := NewEventRelay(0); !errors.Is(err, ErrEventRelayInvalid) {
+		t.Fatalf("NewEventRelay(0) error = %v", err)
+	}
+	relay, err := NewEventRelay(1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	relay.Close()
+	if err := relay.Submit(
+		context.Background(),
+		Event{Type: EventCatalogRefreshed},
+	); !errors.Is(err, ErrEventRelayClosed) {
+		t.Fatalf("Submit(after Close) error = %v", err)
+	}
+}
+
+func waitRelayResult(result <-chan error) error {
+	select {
+	case err := <-result:
+		return err
+	case <-time.After(2 * time.Second):
+		return errors.New("timed out waiting for relay")
+	}
+}
+
+func waitSignal(t *testing.T, signal <-chan struct{}) {
+	t.Helper()
+	select {
+	case <-signal:
+	case <-time.After(2 * time.Second):
+		t.Fatal("timed out waiting for signal")
+	}
+}