add test to assert MapIterator failure against keyless (queues) maps

This commit introduces the `TestIterateWrongMap` test, which should
assert that the `MapIterator` fails while called on keyless maps such as
queues. We do not expect different behaviours, as the `MapIterator.Next`
relies on the presence of a key for which it lookups the value.
A different method can be later introduces to also traverse a queue, but
in that case we'd need to additionally remove the value.

Signed-off-by: Simone Magnani <simone.magnani@isovalent.com>

map_test.go

@@ -1123,6 +1123,28 @@ func TestMapIterate(t *testing.T) {
  qt.Assert(t, qt.DeepEquals(keys, data))
 }
 
+func TestIterateWrongMap(t *testing.T) {
+ testutils.SkipOnOldKernel(t, "4.20", "map type queue")
+
+ m, err := NewMap(&MapSpec{
+ Type: Queue,
+ ValueSize: 4,
+ MaxEntries: 2,
+ Contents: []MapKV{
+ {nil, uint32(0)},
+ {nil, uint32(1)},
+ },
+ })
+ qt.Assert(t, qt.IsNil(err))
+ defer m.Close()
+
+ var value uint32
+ entries := m.Iterate()
+
+ qt.Assert(t, qt.IsFalse(entries.Next(nil, &value)))
+ qt.Assert(t, qt.IsNotNil(entries.Err()))
+}
+
 func TestMapIteratorAllocations(t *testing.T) {
  arr, err := NewMap(&MapSpec{
  Type: Array,