orchard

 1package main
 2
 3import (
 4	"testing"
 5	"time"
 6)
 7
 8func TestHubReachesEveryOpenTab(t *testing.T) {
 9	h := NewHub()
10	a, closeA := h.Subscribe()
11	b, closeB := h.Subscribe()
12	defer closeA()
13	defer closeB()
14
15	h.Publish(HubEvent{Kind: "finished", ConvID: "c1", Title: "A title"})
16	for _, ch := range []<-chan HubEvent{a, b} {
17		select {
18		case ev := <-ch:
19			if ev.ConvID != "c1" || ev.Title != "A title" {
20				t.Errorf("got %#v", ev)
21			}
22		case <-time.After(time.Second):
23			t.Fatal("a subscriber was not told")
24		}
25	}
26}
27
28// A tab on a locked phone stops reading. Waiting on it would stall the turn
29// doing the publishing and every other tab with it, and these events are a hint
30// to go and re-read rather than a record that has to arrive.
31func TestHubDoesNotBlockOnATabThatStoppedReading(t *testing.T) {
32	h := NewHub()
33	_, cancel := h.Subscribe()
34	defer cancel()
35
36	done := make(chan struct{})
37	go func() {
38		for i := 0; i < hubBuffer*4; i++ {
39			h.Publish(HubEvent{Kind: "finished", ConvID: "c1"})
40		}
41		close(done)
42	}()
43	select {
44	case <-done:
45	case <-time.After(2 * time.Second):
46		t.Fatal("publishing blocked on a subscriber that was not reading")
47	}
48}
49
50// Unsubscribing has to be safe to call twice, since the handler defers it and
51// an error path calls it as well.
52func TestHubCancelIsIdempotent(t *testing.T) {
53	h := NewHub()
54	_, cancel := h.Subscribe()
55	cancel()
56	cancel()
57	h.Publish(HubEvent{Kind: "changed"})
58	if n := h.Len(); n != 0 {
59		t.Errorf("%d subscribers left after cancel", n)
60	}
61}