Fix more tests

cmd_generic_test.go

@@ -774,23 +774,21 @@ func TestCopy(t *testing.T) {
 	s.Set("key1", "value")
 	s.CheckGet(t, "key1", "value")
 	s.Copy("key1", "key2")
-	must0(t, c, "COPY", "key1", "key2")
+	// should return 1 after a successful copy operation:
+	must1(t, c, "COPY", "key1", "key2")
 	s.CheckGet(t, "key2", "value")
 
-	// should fail when trying to copy a nonexistent key:
+	// should return 0 when trying to copy a nonexistent key:
 	t.Run("nonexistent key", func(t *testing.T) {
-		mustDo(t, c,
-			"COPY", "nosuch", "to",
-			proto.Error("ERR no such key"),
-		)
+		must0(t, c, "COPY", "nosuch", "to")
 	})
 
-	// should return 1 when a key already exists:
+	// should return 0 when trying to overwrite an existing key:
 	t.Run("existing key", func(t *testing.T) {
 		s.Set("existingkey", "value")
 		s.Set("newkey", "newvalue")
-		must1(t, c, "COPY", "newkey", "existingkey")
-		// existing key value should be preserved:
+		must0(t, c, "COPY", "newkey", "existingkey")
+		// existing key value should remain unchanged:
 		s.CheckGet(t, "existingkey", "value")
 	})
 }