diff --git a/swh/lister/core/tests/conftest.py b/swh/lister/core/tests/conftest.py
new file mode 100644
--- /dev/null
+++ b/swh/lister/core/tests/conftest.py
@@ -0,0 +1,23 @@
+import pytest
+
+
+@pytest.fixture(scope='session')
+def celery_enable_logging():
+    return True
+
+
+@pytest.fixture(scope='session')
+def celery_includes():
+    return [
+        'swh.lister.github.tasks',
+    ]
+
+
+# override the celery_session_app fixture to monkeypatch the 'main'
+# swh.scheduler.celery_backend.config.app Celery application
+# with the test application.
+@pytest.fixture(scope='session')
+def swh_app(celery_session_app):
+    import swh.scheduler.celery_backend.config
+    swh.scheduler.celery_backend.config.app = celery_session_app
+    yield celery_session_app
diff --git a/swh/lister/github/tasks.py b/swh/lister/github/tasks.py
--- a/swh/lister/github/tasks.py
+++ b/swh/lister/github/tasks.py
@@ -46,9 +46,11 @@
     lister = new_lister(**lister_args)
     ranges = lister.db_partition_indices(split or GROUP_SPLIT)
     random.shuffle(ranges)
-    group(range_github_lister.s(minv, maxv, **lister_args)
-          for minv, maxv in ranges)()
+    promise = group(range_github_lister.s(minv, maxv, **lister_args)
+                    for minv, maxv in ranges)()
     self.log.debug('%s OK (spawned %s subtasks)' % (self.name, len(ranges)))
+    promise.save()  # so that we can restore the GroupResult in tests
+    return promise.id
 
 
 @app.task(name='swh.lister.github.tasks.ping',
diff --git a/swh/lister/github/tests/conftest.py b/swh/lister/github/tests/conftest.py
new file mode 100644
--- /dev/null
+++ b/swh/lister/github/tests/conftest.py
@@ -0,0 +1 @@
+from swh.lister.core.tests.conftest import *  # noqa
diff --git a/swh/lister/github/tests/test_tasks.py b/swh/lister/github/tests/test_tasks.py
new file mode 100644
--- /dev/null
+++ b/swh/lister/github/tests/test_tasks.py
@@ -0,0 +1,90 @@
+from time import sleep
+from celery.result import GroupResult
+
+from unittest.mock import patch
+
+
+def test_ping(swh_app, celery_session_worker):
+    res = swh_app.send_task(
+        'swh.lister.github.tasks.ping')
+    assert res
+    res.wait()
+    assert res.successful()
+    assert res.result == 'OK'
+
+
+@patch('swh.lister.github.tasks.GitHubLister')
+def test_incremental(lister, swh_app, celery_session_worker):
+    # setup the mocked GitHubLister
+    lister.return_value = lister
+    lister.db_last_index.return_value = 42
+    lister.run.return_value = None
+
+    res = swh_app.send_task(
+        'swh.lister.github.tasks.IncrementalGitHubLister')
+    assert res
+    res.wait()
+    assert res.successful()
+
+    lister.assert_called_once_with(api_baseurl='https://api.github.com')
+    lister.db_last_index.assert_called_once_with()
+    lister.run.assert_called_once_with(min_bound=42, max_bound=None)
+
+
+@patch('swh.lister.github.tasks.GitHubLister')
+def test_range(lister, swh_app, celery_session_worker):
+    # setup the mocked GitHubLister
+    lister.return_value = lister
+    lister.run.return_value = None
+
+    res = swh_app.send_task(
+        'swh.lister.github.tasks.RangeGitHubLister',
+        kwargs=dict(start=12, end=42))
+    assert res
+    res.wait()
+    assert res.successful()
+
+    lister.assert_called_once_with(api_baseurl='https://api.github.com')
+    lister.db_last_index.assert_not_called()
+    lister.run.assert_called_once_with(min_bound=12, max_bound=42)
+
+
+@patch('swh.lister.github.tasks.GitHubLister')
+def test_relister(lister, swh_app, celery_session_worker):
+    # setup the mocked GitHubLister
+    lister.return_value = lister
+    lister.run.return_value = None
+    lister.db_partition_indices.return_value = [
+        (i, i+9) for i in range(0, 50, 10)]
+
+    res = swh_app.send_task(
+        'swh.lister.github.tasks.FullGitHubRelister')
+    assert res
+
+    res.wait()
+    assert res.successful()
+
+    # retrieve the GroupResult for this task and wait for all the subtasks
+    # to complete
+    promise_id = res.result
+    assert promise_id
+    promise = GroupResult.restore(promise_id, app=swh_app)
+    for i in range(5):
+        if promise.ready():
+            break
+        sleep(1)
+
+    lister.assert_called_with(api_baseurl='https://api.github.com')
+
+    # one by the FullGitHubRelister task
+    # + 5 for the RangeGitHubLister subtasks
+    assert lister.call_count == 6
+
+    lister.db_last_index.assert_not_called()
+    lister.db_partition_indices.assert_called_once_with(10000)
+
+    # lister.run should have been called once per partition interval
+    for i in range(5):
+        # XXX inconsistent behavior: max_bound is INCLUDED here
+        assert (dict(min_bound=10*i, max_bound=10*i + 9),) \
+            in lister.run.call_args_list