| 1 | package main |
| 2 | |
| 3 | import ( |
| 4 | "net/http" |
| 5 | "net/http/httptest" |
| 6 | "path/filepath" |
| 7 | "sync/atomic" |
| 8 | "testing" |
| 9 | "time" |
| 10 | ) |
| 11 | |
| 12 | // closeMirrorFixture registers a mirror for sessionPath against a stub Serve |
| 13 | // that records when the farewell arrives. |
| 14 | func closeMirrorFixture(t *testing.T, app *App, sessionPath string) (*takeoverMirror, *atomic.Int32) { |
| 15 | t.Helper() |
| 16 | var ends atomic.Int32 |
| 17 | srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 18 | if r.URL.Path == "/mirror-end" { |
| 19 | ends.Add(1) |
| 20 | w.WriteHeader(http.StatusNoContent) |
| 21 | return |
| 22 | } |
| 23 | w.WriteHeader(http.StatusNotFound) |
| 24 | })) |
| 25 | t.Cleanup(srv.Close) |
| 26 | m := &takeoverMirror{ |
| 27 | app: app, key: sessionRuntimeKey(sessionPath), sessionPath: sessionPath, |
| 28 | client: srv.Client(), record: takeoverServeRecord{base: srv.URL}, |
| 29 | grant: takeoverGrant{MirrorID: "mirror"}, |
| 30 | wake: make(chan struct{}, 1), |
| 31 | } |
| 32 | app.takeoverMu.Lock() |
| 33 | if app.takeoverMirrors == nil { |
| 34 | app.takeoverMirrors = map[string]*takeoverMirror{} |
| 35 | } |
| 36 | app.takeoverMirrors[m.key] = m |
| 37 | app.takeoverMu.Unlock() |
| 38 | return m, &ends |
| 39 | } |
| 40 | |
| 41 | // Serve waits for the writer to drop before reclaiming a mirrored session, so |
| 42 | // the farewell must follow the writer release rather than race it. A closing |
| 43 | // tab claims the farewell while it still owns the writer and sends it after |
| 44 | // the release; the mirror loop's tab-gone branch must not pre-empt that. |
| 45 | func TestClosingTabOwnsTheMirrorFarewellUntilTheWriterIsReleased(t *testing.T) { |
| 46 | app := NewApp() |
| 47 | path := filepath.Join(t.TempDir(), "closing.jsonl") |
| 48 | m, ends := closeMirrorFixture(t, app, path) |
| 49 | |
| 50 | claimed, release := app.claimTakeoverMirrorFarewell(path) |
| 51 | if claimed != m || !m.closing.Load() { |
| 52 | t.Fatalf("claim = %p, want the registered mirror marked closing", claimed) |
| 53 | } |
| 54 | defer release() |
| 55 | // While the close is still tearing the writer down, the loop's tab-gone |
| 56 | // branch only detaches: announcing the writer as gone here is exactly the |
| 57 | // ordering that makes Serve wait. |
| 58 | m.detach() |
| 59 | if !m.closing.Load() { |
| 60 | t.Fatal("detach cleared the close claim") |
| 61 | } |
| 62 | if ends.Load() != 0 { |
| 63 | t.Fatalf("farewell sent %d times before the writer was released", ends.Load()) |
| 64 | } |
| 65 | |
| 66 | app.endTakeoverMirrorForClosedTab(m) |
| 67 | deadline := time.Now().Add(20 * time.Second) |
| 68 | for ends.Load() == 0 { |
| 69 | if time.Now().After(deadline) { |
| 70 | t.Fatal("the close epilogue never sent the farewell") |
| 71 | } |
| 72 | time.Sleep(time.Millisecond) |
| 73 | } |
| 74 | |
| 75 | // A delivered farewell is not repeated: the loop's backstop and the close |
| 76 | // epilogue must not both announce the writer as gone. |
| 77 | m.mirrorEnd() |
| 78 | if got := ends.Load(); got != 1 { |
| 79 | t.Fatalf("farewell sent %d times, want exactly one", got) |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | // An undelivered farewell stays unmarked so a later path can retry it. |
| 84 | func TestUndeliveredMirrorFarewellStaysRetryable(t *testing.T) { |
| 85 | app := NewApp() |
| 86 | path := filepath.Join(t.TempDir(), "unreachable.jsonl") |
| 87 | m, _ := closeMirrorFixture(t, app, path) |
| 88 | m.mu.Lock() |
| 89 | m.record = takeoverServeRecord{base: "http://127.0.0.1:1"} |
| 90 | m.mu.Unlock() |
| 91 | |
| 92 | m.mirrorEnd() |
| 93 | if m.ended.Load() { |
| 94 | t.Fatal("a failed farewell was recorded as delivered") |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | // A close that returns early keeps its writer, so the farewell claim goes back |
| 99 | // to the mirror loop instead of stranding the mirror silent. |
| 100 | func TestAbandonedCloseReturnsTheFarewellClaim(t *testing.T) { |
| 101 | app := NewApp() |
| 102 | path := filepath.Join(t.TempDir(), "abandoned.jsonl") |
| 103 | m, ends := closeMirrorFixture(t, app, path) |
| 104 | |
| 105 | func() { |
| 106 | _, release := app.claimTakeoverMirrorFarewell(path) |
| 107 | defer release() |
| 108 | // The close bails out here (detached runtime, or the tab changed). |
| 109 | }() |
| 110 | |
| 111 | if m.closing.Load() { |
| 112 | t.Fatal("an abandoned close kept the farewell claim") |
| 113 | } |
| 114 | m.mirrorEnd() |
| 115 | if ends.Load() != 1 { |
| 116 | t.Fatalf("farewell sent %d times after the claim was returned, want one", ends.Load()) |
| 117 | } |
| 118 | } |
| 119 |