tests: add testcase to ensure reader routine terminates

Add a testcase for the bug that the reader go-routine tries to send a
message to the buffered rpc channel but call() terminated because it
read an error from the errors chan or the errors chan was closed.
It cause that reader routine gets stuck forever and does not terminate
when the connection is closed.
More information: rabbitmq#69.

This testcase does not reproduce the issue reliably, but it is triggered
in ~80% of executions.

connection_test.go

@@ -14,6 +14,8 @@ import (
 	"sync"
 	"testing"
 	"time"
+
+	"go.uber.org/goleak"
 )
 
 func TestRequiredServerLocale(t *testing.T) {
@@ -210,3 +212,32 @@ func TestChannelIsClosed(t *testing.T) {
 		t.Fatal("channel expected to be marked as closed")
 	}
 }
+
+// TestReaderGoRoutineTerminatesWhenMsgIsProcessedDuringClose tests the issue
+// described in https://github.com/rabbitmq/amqp091-go/issues/69.
+func TestReaderGoRoutineTerminatesWhenMsgIsProcessedDuringClose(t *testing.T) {
+	const routines = 10
+	defer goleak.VerifyNone(t)
+	c := integrationConnection(t, t.Name())
+
+	var wg sync.WaitGroup
+	startSigCh := make(chan interface{})
+
+	for i := 0; i < routines; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+
+			<-startSigCh
+
+			err := c.Close()
+			if err != nil {
+				t.Logf("close failed in routine %d: %s", id, err.Error())
+			}
+		}(i)
+	}
+	close(startSigCh)
+
+	t.Log("waiting for go-routines to terminate")
+	wg.Wait()
+}

go.mod

@@ -1,3 +1,5 @@
 module github.com/rabbitmq/amqp091-go
 
 go 1.16
+
+require go.uber.org/goleak v1.1.12