feat: backend service

backend/push/ring_test.go

@@ -0,0 +1,105 @@
+package push
+
+import (
+	"testing"
+	"time"
+
+	pushv1 "galaxy/backend/proto/push/v1"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func mkEvent(cursor uint64, label string) *pushv1.PushEvent {
+	return &pushv1.PushEvent{
+		Cursor: formatCursor(cursor),
+		Kind: &pushv1.PushEvent_ClientEvent{
+			ClientEvent: &pushv1.ClientEvent{
+				Kind:    label,
+				Payload: []byte(label),
+			},
+		},
+	}
+}
+
+func TestRingAppendAndSinceReturnsTail(t *testing.T) {
+	t.Parallel()
+
+	now := time.Unix(1_700_000_000, 0)
+	r := newRing(8, time.Minute)
+	for i := uint64(1); i <= 5; i++ {
+		r.append(i, mkEvent(i, "e"), now)
+	}
+
+	got, stale := r.since(2, now)
+	require.False(t, stale)
+	require.Len(t, got, 3)
+	assert.Equal(t, formatCursor(3), got[0].Cursor)
+	assert.Equal(t, formatCursor(4), got[1].Cursor)
+	assert.Equal(t, formatCursor(5), got[2].Cursor)
+}
+
+func TestRingSinceReturnsEmptyWhenCaughtUp(t *testing.T) {
+	t.Parallel()
+
+	now := time.Unix(1_700_000_000, 0)
+	r := newRing(8, time.Minute)
+	for i := uint64(1); i <= 3; i++ {
+		r.append(i, mkEvent(i, "e"), now)
+	}
+
+	got, stale := r.since(3, now)
+	require.False(t, stale)
+	assert.Empty(t, got)
+
+	got, stale = r.since(99, now)
+	require.False(t, stale)
+	assert.Empty(t, got)
+}
+
+func TestRingSinceFlagsStaleCursorBelowEvictedRange(t *testing.T) {
+	t.Parallel()
+
+	now := time.Unix(1_700_000_000, 0)
+	r := newRing(3, time.Minute)
+	for i := uint64(1); i <= 5; i++ {
+		r.append(i, mkEvent(i, "e"), now)
+	}
+	// Capacity=3 means cursors 1 and 2 were evicted.
+	require.Equal(t, 3, r.len())
+
+	got, stale := r.since(1, now)
+	assert.True(t, stale)
+	assert.Empty(t, got)
+
+	got, stale = r.since(2, now)
+	assert.False(t, stale)
+	require.Len(t, got, 3)
+	assert.Equal(t, formatCursor(3), got[0].Cursor)
+}
+
+func TestRingEvictsExpiredEntries(t *testing.T) {
+	t.Parallel()
+
+	t0 := time.Unix(1_700_000_000, 0)
+	r := newRing(8, 10*time.Second)
+	r.append(1, mkEvent(1, "e"), t0)
+	r.append(2, mkEvent(2, "e"), t0.Add(2*time.Second))
+	r.append(3, mkEvent(3, "e"), t0.Add(15*time.Second))
+
+	// At t0+13s the first two entries are past their 10s TTL but the
+	// third (added at t0+15s) is still within the freshness window.
+	got, stale := r.since(0, t0.Add(13*time.Second))
+	assert.True(t, stale)
+	assert.Empty(t, got)
+	assert.Equal(t, 1, r.len())
+}
+
+func TestRingEmptyIsNeverStale(t *testing.T) {
+	t.Parallel()
+
+	r := newRing(4, time.Minute)
+	got, stale := r.since(42, time.Now())
+	assert.False(t, stale)
+	assert.Empty(t, got)
+}