Fix mmd.copy calls to support PackagerV3

Fixes #1685

tests/staged_data/v3/mmd_packager.yaml

@@ -4,7 +4,7 @@ document: modulemd-packager
 version: 3
 data:
     name: foo
-    stream: latest
+    stream: master
     summary: An example module
     description: >-
         A module for the demonstration of the metadata format. Also,

tests/test_common/test_submit.py

@@ -4,7 +4,9 @@ from __future__ import absolute_import
 
 import mock
 
-from module_build_service.common.submit import _is_eol_in_pdc
+from module_build_service.common.modulemd import Modulemd
+from module_build_service.common.submit import _is_eol_in_pdc, fetch_mmd
+from tests.test_web.test_views import FakeSCM
 
 
 @mock.patch("module_build_service.common.submit.requests")
@@ -32,3 +34,31 @@ def test_pdc_eol_check(requests):
 
     is_eol = _is_eol_in_pdc("mariadb", "10.1")
     assert is_eol
+
+
+@mock.patch("module_build_service.common.scm.SCM")
+def test_fetch_mmd(mocked_scm):
+    """ Test behavior for fetch_mmd """
+
+    FakeSCM(
+        mocked_scm,
+        "testmodule",
+        "testmodule.yaml",
+        "620ec77321b2ea7b0d67d82992dda3e1d67055b4")
+
+    mmd, scm = fetch_mmd('testurl')
+    assert isinstance(mmd, Modulemd.ModuleStream)
+
+
+@mock.patch("module_build_service.common.scm.SCM")
+def test_fetch_mmd_packager_v3(mocked_scm):
+    """ Test PackagerV3 behavior for fetch_mmd """
+
+    FakeSCM(
+        mocked_scm,
+        "foo",
+        "v3/mmd_packager.yaml",
+        "620ec77321b2ea7b0d67d82992dda3e1d67055b4")
+
+    mmd, scm = fetch_mmd('testurl')
+    assert not isinstance(mmd, Modulemd.ModuleStream)

tests/test_web/test_submit.py

@@ -300,6 +300,36 @@ class TestUtilsComponentReuse:
             assert username_arg == username
         rmtree(module_dir)
 
+    @mock.patch("module_build_service.web.submit.submit_module_build")
+    def test_submit_module_build_from_yaml_packager_v3(self, mock_submit):
+        """
+        Tests local module build from a yaml file with the skiptests option
+
+        Args:
+            mock_submit (MagickMock): mocked function submit_module_build, which we then
+                inspect if it was called with correct arguments
+        """
+        module_dir = tempfile.mkdtemp()
+        modulemd_yaml = read_staged_data("v3/mmd_packager")
+        modulemd_file_path = path.join(module_dir, "testmodule.yaml")
+
+        username = "test"
+        stream = "dev"
+
+        with io.open(modulemd_file_path, "w", encoding="utf-8") as fd:
+            fd.write(modulemd_yaml)
+
+        with open(modulemd_file_path, "rb") as fd:
+            handle = FileStorage(fd)
+            submit_module_build_from_yaml(
+                db_session, username, handle, {}, stream=stream, skiptests=False)
+            mock_submit_args = mock_submit.call_args[0]
+            username_arg = mock_submit_args[1]
+            mmd_arg = mock_submit_args[2]
+            assert mmd_arg.get_stream_name() == stream
+            assert username_arg == username
+        rmtree(module_dir)
+
     @mock.patch("module_build_service.web.submit.generate_expanded_mmds")
     def test_submit_build_new_mse_build(self, generate_expanded_mmds):
         """