test: add Drop to fuzz test, add drop test cases

cuckoo_test.go

@@ -129,7 +129,7 @@ func TestRemove(t *testing.T) {
 	assert.True(table.Has(0))
 }
 
-func TestDropItem(t *testing.T) {
+func TestDropExistingItem(t *testing.T) {
 	assert := assert.New(t)
 	key, value := 0, true
 	table := cuckoo.NewTable[int, bool]()
@@ -141,3 +141,15 @@ func TestDropItem(t *testing.T) {
 	assert.Equal(0, table.Size())
 	assert.False(table.Has(key))
 }
+
+func TestDropNoItem(t *testing.T) {
+	assert := assert.New(t)
+	key := 0
+	table := cuckoo.NewTable[int, bool]()
+
+	err := table.Drop(key)
+
+	assert.NoError(err)
+	assert.Equal(0, table.Size())
+	assert.False(table.Has(key))
+}