clist: add a few basic clist tests (#6727)

internal/libs/clist/clist_test.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestPanicOnMaxLength(t *testing.T) {
@@ -334,3 +335,50 @@ FOR_LOOP2:
 		t.Fatalf("number of pushed items (%d) not equal to number of seen items (%d)", pushed, seen)
 	}
 }
+
+func TestRemoved(t *testing.T) {
+	l := New()
+	el1 := l.PushBack(1)
+	el2 := l.PushBack(2)
+	l.Remove(el1)
+	require.True(t, el1.Removed())
+	require.False(t, el2.Removed())
+}
+
+func TestNextWaitChan(t *testing.T) {
+	l := New()
+	el1 := l.PushBack(1)
+	t.Run("tail element should not have a closed nextWaitChan", func(t *testing.T) {
+		select {
+		case <-el1.NextWaitChan():
+			t.Fatal("nextWaitChan should not have been closed")
+		default:
+		}
+	})
+
+	el2 := l.PushBack(2)
+	t.Run("adding element should close tail nextWaitChan", func(t *testing.T) {
+		select {
+		case <-el1.NextWaitChan():
+			require.NotNil(t, el1.Next())
+		default:
+			t.Fatal("nextWaitChan should have been closed")
+		}
+
+		select {
+		case <-el2.NextWaitChan():
+			t.Fatal("nextWaitChan should not have been closed")
+		default:
+		}
+	})
+
+	t.Run("removing element should close its nextWaitChan", func(t *testing.T) {
+		l.Remove(el2)
+		select {
+		case <-el2.NextWaitChan():
+			require.Nil(t, el2.Next())
+		default:
+			t.Fatal("nextWaitChan should have been closed")
+		}
+	})
+}