.

go/internal/xtracing/tracetest/tracetest.go

@@ -636,7 +636,6 @@ func (t *T) xget1(stream string, eventp interface{}) *Msg {
 		// ok
 
 	case <-time.After(*deadTime):
-		//t.deadlock(stream, eventp)
 		t.Fatalf("%s: recv: deadlock waiting for %T\n", stream, eventp)
 	}
 
@@ -673,6 +672,26 @@ func (t *T) fatalfInNonMain(format string, argv ...interface{}) {
 // T overrides FailNow/Fatal/Fatalf to also cancel all in-progress sends.
 func (t *T) FailNow() {
 	t.Helper()
+	_ = t.closeStreamTab()
+	t.TB.FailNow()
+}
+
+func (t *T) Fatal(argv ...interface{}) {
+	t.Helper()
+	t.Log(argv...)
+	t.FailNow()
+}
+
+func (t *T) Fatalf(format string, argv ...interface{}) {
+	t.Helper()
+	t.Logf(format, argv...)
+	t.FailNow()
+}
+
+// closeStreamTab prints details about pending event on streamTab, naks them
+// and closes all channels. It returns the number of naked messages.
+func (t *T) closeStreamTab() (nnak int) {
+	t.Helper()
 
 	// mark streamTab no longer operational
 	t.streamTabMu.Lock()
@@ -680,6 +699,10 @@ func (t *T) FailNow() {
 	t.streamTab = nil
 	t.streamTabMu.Unlock()
 
+	if streamTab == nil {
+		return // already closed
+	}
+
 	// print details about pending events and all streams
 	type sendInfo struct{ch Chan; msg *Msg}
 	var sendv  []sendInfo // sends are pending here
@@ -719,27 +742,19 @@ func (t *T) FailNow() {
 	t.Log(pending)
 	for _, __ := range t.nakq {
 		__.msg.nak(__.why)
+		nnak++
 	}
+	t.nakq = nil
 	for _, __ := range sendv {
 		__.msg.nak("canceled (test failed)")
+		nnak++
 	}
 	// in any case close channel where future Sends may arrive so that they will "panic" too.
 	for _, ch := range streamTab {
 		ch.Close()
 	}
-	t.TB.FailNow()
-}
 
-func (t *T) Fatal(argv ...interface{}) {
-	t.Helper()
-	t.Log(argv...)
-	t.FailNow()
-}
-
-func (t *T) Fatalf(format string, argv ...interface{}) {
-	t.Helper()
-	t.Logf(format, argv...)
-	t.FailNow()
+	return nnak
 }
 
 
@@ -759,13 +774,17 @@ func Verify(t testing.TB, f func(t *T)) {
 	tT := &T{TB: t, streamTab: make(map[string]Chan)}
 	// XXX
 
-	// XXX not here
-/*
-	// verify in the end that no events are left unchecked / unconsumed
-	// (e.g. sent to RxEvent, but not received). Nak them if they are ... XXX
+	// verify in the end that no events are left unchecked / unconsumed,
+	// e.g. sent to RxEvent, but not received. Nak them if they are and fail.
+	//
+	// NOTE this complements T.Fatal and friends, because a test might
+	// think it completes successfully, but leaves unconsumed events behind it.
 	defer func() {
+		nnak := tT.closeStreamTab()
+		if nnak != 0 {
+			t.Fatal()
+		}
 	}()
-*/
 
 	f(tT)