diff --git a/swh/storage/pytest_plugin.py b/swh/storage/pytest_plugin.py
--- a/swh/storage/pytest_plugin.py
+++ b/swh/storage/pytest_plugin.py
@@ -6,7 +6,7 @@
 import glob
 
 from os import path, environ
-from typing import Dict, Union
+from typing import Dict, Iterable, Union
 
 import pytest
 
@@ -16,6 +16,17 @@
 from pytest_postgresql.janitor import DatabaseJanitor, psycopg2, Version
 
 from swh.core.utils import numfile_sortkey as sortkey
+from swh.model.model import (
+    BaseModel,
+    Content,
+    Directory,
+    Origin,
+    Person,
+    Release,
+    Revision,
+    SkippedContent,
+    Snapshot,
+)
 from swh.storage import get_storage
 from swh.storage.tests.storage_data import data
 
@@ -209,3 +220,33 @@
         "authority": [data.metadata_authority],
         "origin_metadata": [data.origin_metadata, data.origin_metadata2],
     }
+
+
+# FIXME: Add the metadata keys when we can (right now, we cannot as the data model
+# changed but not the endpoints yet)
+OBJECT_FACTORY = {
+    "content": Content.from_dict,
+    "content_metadata": Content.from_dict,
+    "skipped_content": SkippedContent.from_dict,
+    "person": Person.from_dict,
+    "directory": Directory.from_dict,
+    "revision": Revision.from_dict,
+    "release": Release.from_dict,
+    "snapshot": Snapshot.from_dict,
+    "origin": Origin.from_dict,
+}
+
+
+@pytest.fixture
+def sample_data_model(sample_data) -> Dict[str, Iterable[BaseModel]]:
+    """Pre-defined sample storage object model to manipulate
+
+    Returns:
+        Dict of data (keys: content, directory, revision, release, person, origin, ...)
+        values list of object data model with the corresponding types
+
+    """
+    return {
+        object_type: [convert_fn(obj) for obj in sample_data[object_type]]
+        for object_type, convert_fn in OBJECT_FACTORY.items()
+    }
diff --git a/swh/storage/tests/conftest.py b/swh/storage/tests/conftest.py
--- a/swh/storage/tests/conftest.py
+++ b/swh/storage/tests/conftest.py
@@ -14,29 +14,6 @@
     pytest_cov = None
 
 from swh.model.tests.generate_testdata import gen_contents, gen_origins
-from swh.model.model import (
-    Content,
-    Directory,
-    Origin,
-    OriginVisit,
-    Release,
-    Revision,
-    SkippedContent,
-    Snapshot,
-)
-
-
-OBJECT_FACTORY = {
-    "content": Content.from_dict,
-    "directory": Directory.from_dict,
-    "origin": Origin.from_dict,
-    "origin_visit": OriginVisit.from_dict,
-    "release": Release.from_dict,
-    "revision": Revision.from_dict,
-    "skipped_content": SkippedContent.from_dict,
-    "snapshot": Snapshot.from_dict,
-}
-
 
 # define tests profile. Full documentation is at:
 # https://hypothesis.readthedocs.io/en/latest/settings.html#settings-profiles
diff --git a/swh/storage/tests/test_pytest_plugin.py b/swh/storage/tests/test_pytest_plugin.py
new file mode 100644
--- /dev/null
+++ b/swh/storage/tests/test_pytest_plugin.py
@@ -0,0 +1,60 @@
+# Copyright (C) 2020  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
+
+
+from swh.storage.pytest_plugin import OBJECT_FACTORY
+
+
+from swh.model.model import BaseModel
+
+
+def test_sample_data(sample_data, sample_data_model):
+    assert set(sample_data.keys()) == set(
+        [
+            "content",
+            "content_metadata",
+            "skipped_content",
+            "person",
+            "directory",
+            "revision",
+            "release",
+            "snapshot",
+            "origin",
+            "fetcher",
+            "authority",
+            "origin_metadata",
+        ]
+    )
+    for object_type, objs in sample_data.items():
+        for obj in objs:
+            assert isinstance(obj, dict)
+
+        if sample_data_model.get(object_type):
+            # metadata keys are missing because conversion is not possible yet
+            assert len(objs) == len(sample_data_model[object_type])
+
+
+def test_sample_data_model(sample_data, sample_data_model):
+    assert set(sample_data_model.keys()) == set(
+        [
+            "content",
+            "content_metadata",
+            "skipped_content",
+            "person",
+            "directory",
+            "revision",
+            "release",
+            "snapshot",
+            "origin",
+        ]
+    )
+
+    for object_type, objs in sample_data_model.items():
+        assert object_type in OBJECT_FACTORY
+
+        for obj in objs:
+            assert isinstance(obj, BaseModel)
+
+        assert len(objs) == len(sample_data[object_type])