diff --git a/swh/loader/git/tests/test_converters.py b/swh/loader/git/tests/test_converters.py
--- a/swh/loader/git/tests/test_converters.py
+++ b/swh/loader/git/tests/test_converters.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2015-2017  The Software Heritage developers
+# Copyright (C) 2015-2018  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -121,6 +121,21 @@
             self.repo[self.blob_id], max_content_size=max_length)
         self.assertEqual(self.blob_hidden, content)
 
+    def test_convertion_wrong_input(self):
+        class Something:
+            type_name = b'something-not-the-right-type'
+
+        m = {
+            'blob': converters.dulwich_blob_to_content,
+            'blob2': converters.dulwich_blob_to_content_id,
+            'tree': converters.dulwich_tree_to_directory,
+            'commit': converters.dulwich_tree_to_directory,
+            'tag': converters.dulwich_tag_to_release,
+        }
+
+        for _callable in m.values():
+            self.assertIsNone(_callable(Something()))
+
     def test_commit_to_revision(self):
         sha1 = b'9768d0b576dbaaecd80abedad6dfd0d72f1476da'
 
@@ -161,6 +176,9 @@
         self.assertEqual(revision, expected_revision)
 
     def test_author_line_to_author(self):
+        # edge case out of the way
+        self.assertIsNone(converters.parse_author(None))
+
         tests = {
             b'a <b@c.com>': {
                 'name': b'a',
@@ -192,6 +210,11 @@
                 'email': b'',
                 'fullname': b' <>',
             },
+            b'something': {
+                'name': None,
+                'email': None,
+                'fullname': b'something'
+            }
         }
 
         for author in sorted(tests):
diff --git a/swh/loader/git/tests/test_tasks.py b/swh/loader/git/tests/test_tasks.py
new file mode 100644
--- /dev/null
+++ b/swh/loader/git/tests/test_tasks.py
@@ -0,0 +1,71 @@
+# Copyright (C) 2018  The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+import datetime
+import unittest
+from unittest.mock import patch
+
+from swh.loader.git.tasks import (
+    UpdateGitRepository, LoadDiskGitRepository,
+    UncompressAndLoadDiskGitRepository
+)
+
+
+class TestTasks(unittest.TestCase):
+    def test_check_task_name(self):
+        task = UpdateGitRepository()
+        self.assertEqual(task.task_queue, 'swh_loader_git')
+
+    @patch('swh.loader.git.updater.BulkUpdater.load')
+    def test_task(self, mock_loader):
+        mock_loader.return_value = {'status': 'eventful'}
+        task = UpdateGitRepository()
+
+        # given
+        actual_result = task.run_task('origin_url')
+
+        self.assertEqual(actual_result, {'status': 'eventful'})
+
+        mock_loader.assert_called_once_with('origin_url', base_url=None)
+
+
+class TestTasks2(unittest.TestCase):
+    def test_check_task_name(self):
+        task = LoadDiskGitRepository()
+        self.assertEqual(task.task_queue, 'swh_loader_git_express')
+
+    @patch('swh.loader.git.loader.GitLoader.load')
+    def test_task(self, mock_loader):
+        mock_loader.return_value = {'status': 'uneventful'}
+        task = LoadDiskGitRepository()
+
+        # given
+        actual_result = task.run_task('origin_url2', '/some/repo',
+                                      '2018-12-10 00:00')
+
+        self.assertEqual(actual_result, {'status': 'uneventful'})
+
+        mock_loader.assert_called_once_with(
+            'origin_url2', '/some/repo', datetime.datetime(2018, 12, 10, 0, 0))
+
+
+class TestTasks3(unittest.TestCase):
+    def test_check_task_name(self):
+        task = UncompressAndLoadDiskGitRepository()
+        self.assertEqual(task.task_queue, 'swh_loader_git_archive')
+
+    @patch('swh.loader.git.loader.GitLoaderFromArchive.load')
+    def test_task(self, mock_loader):
+        mock_loader.return_value = {'status': 'failed'}
+        task = UncompressAndLoadDiskGitRepository()
+
+        # given
+        actual_result = task.run_task('origin_url3', '/path/repo',
+                                      '2017-01-10 00:00')
+
+        self.assertEqual(actual_result, {'status': 'failed'})
+
+        mock_loader.assert_called_once_with(
+            'origin_url3', '/path/repo', datetime.datetime(2017, 1, 10, 0, 0))