feat: wire sse_client_cpp_core for live updates from /api/boards/issues/stream

backend/sse_hub_test.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"testing"
+	"time"
+)
+
+func TestHub_BroadcastReachesSubscriber(t *testing.T) {
+	h := NewHub()
+	ch := h.Subscribe()
+	defer h.Unsubscribe(ch)
+
+	want := ServerEvent{Board: "issues", CardID: "0119", Action: "updated"}
+	h.Broadcast(want)
+
+	select {
+	case got := <-ch:
+		if got != want {
+			t.Fatalf("got %+v, want %+v", got, want)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("timeout waiting for broadcast")
+	}
+}
+
+func TestHub_UnsubscribeStopsDelivery(t *testing.T) {
+	h := NewHub()
+	ch := h.Subscribe()
+	if got := h.Count(); got != 1 {
+		t.Fatalf("Count() = %d, want 1", got)
+	}
+	h.Unsubscribe(ch)
+	if got := h.Count(); got != 0 {
+		t.Fatalf("Count() after Unsubscribe = %d, want 0", got)
+	}
+	// channel should be closed
+	if _, ok := <-ch; ok {
+		t.Fatalf("expected closed channel after Unsubscribe")
+	}
+	// double-unsubscribe is a no-op
+	h.Unsubscribe(ch)
+
+	// broadcast should not panic and should reach nobody
+	h.Broadcast(ServerEvent{Board: "issues", CardID: "x", Action: "updated"})
+}
+
+func TestHub_MultipleSubscribersAllReceive(t *testing.T) {
+	h := NewHub()
+	const n = 5
+	chans := make([]chan ServerEvent, n)
+	for i := range chans {
+		chans[i] = h.Subscribe()
+	}
+	defer func() {
+		for _, ch := range chans {
+			h.Unsubscribe(ch)
+		}
+	}()
+
+	want := ServerEvent{Board: "flows", CardID: "abc", Action: "created", EventType: "card_added"}
+	h.Broadcast(want)
+
+	for i, ch := range chans {
+		select {
+		case got := <-ch:
+			if got != want {
+				t.Fatalf("sub %d: got %+v, want %+v", i, got, want)
+			}
+		case <-time.After(time.Second):
+			t.Fatalf("sub %d: timeout", i)
+		}
+	}
+}