add a test that leaves streams open

suites/mux/muxer_suite.go

@@ -545,6 +545,60 @@ func SubtestWriteAfterClose(t *testing.T, tr network.Multiplexer) {
 	}
 }
 
+func SubtestStreamLeftOpen(t *testing.T, tr network.Multiplexer) {
+	a, b := tcpPipe(t)
+
+	const numStreams = 10
+	const dataLen = 50 * 1024
+
+	scopea := &peerScope{}
+	muxa, err := tr.NewConn(a, true, scopea)
+	checkErr(t, err)
+
+	scopeb := &peerScope{}
+	muxb, err := tr.NewConn(b, false, scopeb)
+	checkErr(t, err)
+
+	var wg sync.WaitGroup
+	wg.Add(1 + numStreams)
+	go func() {
+		defer wg.Done()
+		for i := 0; i < numStreams; i++ {
+			stra, err := muxa.OpenStream(context.Background())
+			checkErr(t, err)
+			go func() {
+				defer wg.Done()
+				_, err = stra.Write(randBuf(dataLen))
+				checkErr(t, err)
+				// do NOT close or reset the stream
+			}()
+		}
+	}()
+
+	wg.Add(1 + numStreams)
+	go func() {
+		defer wg.Done()
+		for i := 0; i < numStreams; i++ {
+			str, err := muxb.AcceptStream()
+			checkErr(t, err)
+			go func() {
+				defer wg.Done()
+				_, err = io.ReadFull(str, make([]byte, dataLen))
+				checkErr(t, err)
+			}()
+		}
+	}()
+
+	// Now we have a bunch of open streams.
+	// Make sure that their memory is returned when we close the connection.
+	wg.Wait()
+
+	muxa.Close()
+	scopea.Check(t)
+	muxb.Close()
+	scopeb.Check(t)
+}
+
 func SubtestStress1Conn1Stream1Msg(t *testing.T, tr network.Multiplexer) {
 	SubtestStress(t, Options{
 		tr:        tr,
@@ -623,6 +677,7 @@ var subtests = []TransportTest{
 	SubtestStress1Conn100Stream100Msg10MB,
 	SubtestStreamOpenStress,
 	SubtestStreamReset,
+	SubtestStreamLeftOpen,
 }
 
 // SubtestAll runs all the stream multiplexer tests against the target