diff --git a/swh/loader/package/archive/tests/test_archive.py b/swh/loader/package/archive/tests/test_archive.py
index 497e471..200f99c 100644
--- a/swh/loader/package/archive/tests/test_archive.py
+++ b/swh/loader/package/archive/tests/test_archive.py
@@ -1,345 +1,345 @@
 # Copyright (C) 2019-2020 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.model.hashutil import hash_to_bytes
+from swh.model.model import Snapshot, SnapshotBranch, TargetType
 
 from swh.loader.package.archive.loader import ArchiveLoader
 from swh.loader.package.tests.common import check_metadata_paths
 from swh.loader.tests import (
     assert_last_visit_matches,
     check_snapshot,
     get_stats,
 )
 
 
 URL = "https://ftp.gnu.org/gnu/8sync/"
 GNU_ARTIFACTS = [
     {
         "time": 944729610,
         "url": "https://ftp.gnu.org/gnu/8sync/8sync-0.1.0.tar.gz",
         "length": 221837,
         "filename": "8sync-0.1.0.tar.gz",
         "version": "0.1.0",
     }
 ]
 
 _expected_new_contents_first_visit = [
     "e9258d81faf5881a2f96a77ba609396f82cb97ad",
     "1170cf105b04b7e2822a0e09d2acf71da7b9a130",
     "fbd27c3f41f2668624ffc80b7ba5db9b92ff27ac",
     "0057bec9b5422aff9256af240b177ac0e3ac2608",
     "2b8d0d0b43a1078fc708930c8ddc2956a86c566e",
     "27de3b3bc6545d2a797aeeb4657c0e215a0c2e55",
     "2e6db43f5cd764e677f416ff0d0c78c7a82ef19b",
     "ae9be03bd2a06ed8f4f118d3fe76330bb1d77f62",
     "edeb33282b2bffa0e608e9d2fd960fd08093c0ea",
     "d64e64d4c73679323f8d4cde2643331ba6c20af9",
     "7a756602914be889c0a2d3952c710144b3e64cb0",
     "84fb589b554fcb7f32b806951dcf19518d67b08f",
     "8624bcdae55baeef00cd11d5dfcfa60f68710a02",
     "e08441aeab02704cfbd435d6445f7c072f8f524e",
     "f67935bc3a83a67259cda4b2d43373bd56703844",
     "809788434b433eb2e3cfabd5d591c9a659d5e3d8",
     "7d7c6c8c5ebaeff879f61f37083a3854184f6c41",
     "b99fec102eb24bffd53ab61fc30d59e810f116a2",
     "7d149b28eaa228b3871c91f0d5a95a2fa7cb0c68",
     "f0c97052e567948adf03e641301e9983c478ccff",
     "7fb724242e2b62b85ca64190c31dcae5303e19b3",
     "4f9709e64a9134fe8aefb36fd827b84d8b617ab5",
     "7350628ccf194c2c3afba4ac588c33e3f3ac778d",
     "0bb892d9391aa706dc2c3b1906567df43cbe06a2",
     "49d4c0ce1a16601f1e265d446b6c5ea6b512f27c",
     "6b5cc594ac466351450f7f64a0b79fdaf4435ad3",
     "3046e5d1f70297e2a507b98224b6222c9688d610",
     "1572607d456d7f633bc6065a2b3048496d679a31",
 ]
 
 _expected_new_directories_first_visit = [
     "daabc65ec75d487b1335ffc101c0ac11c803f8fc",
     "263be23b4a8101d3ad0d9831319a3e0f2b065f36",
     "7f6e63ba6eb3e2236f65892cd822041f1a01dd5c",
     "4db0a3ecbc976083e2dac01a62f93729698429a3",
     "dfef1c80e1098dd5deda664bb44a9ab1f738af13",
     "eca971d346ea54d95a6e19d5051f900237fafdaa",
     "3aebc29ed1fccc4a6f2f2010fb8e57882406b528",
 ]
 
 _expected_new_revisions_first_visit = {
     "44183488c0774ce3c957fa19ba695cf18a4a42b3": (
         "3aebc29ed1fccc4a6f2f2010fb8e57882406b528"
     )
 }
 
-_expected_branches_first_visit = {
-    b"HEAD": {"target_type": "alias", "target": b"releases/0.1.0",},
-    b"releases/0.1.0": {
-        "target_type": "revision",
-        "target": hash_to_bytes("44183488c0774ce3c957fa19ba695cf18a4a42b3"),
-    },
-}
-
-# hash is different then before as we changed the snapshot
-# gnu used to use `release/` (singular) instead of plural
-_expected_new_snapshot_first_visit_id = hash_to_bytes(
-    "c419397fd912039825ebdbea378bc6283f006bf5"
-)
-
 
 def visit_with_no_artifact_found(swh_config, requests_mock_datadir):
     url = URL
     unknown_artifact_url = "https://ftp.g.o/unknown/8sync-0.1.0.tar.gz"
     loader = ArchiveLoader(
         url,
         artifacts=[
             {
                 "time": 944729610,
                 "url": unknown_artifact_url,  # unknown artifact
                 "length": 221837,
                 "filename": "8sync-0.1.0.tar.gz",
                 "version": "0.1.0",
             }
         ],
     )
 
     actual_load_status = loader.load()
     assert actual_load_status["status"] == "uneventful"
     assert actual_load_status["snapshot_id"] is not None
     stats = get_stats(loader.storage)
 
     assert {
         "content": 0,
         "directory": 0,
         "origin": 1,
         "origin_visit": 1,
         "person": 0,
         "release": 0,
         "revision": 0,
         "skipped_content": 0,
         "snapshot": 1,
     } == stats
 
     assert_last_visit_matches(loader.storage, url, status="partial", type="tar")
 
 
 def test_check_revision_metadata_structure(swh_config, requests_mock_datadir):
     loader = ArchiveLoader(url=URL, artifacts=GNU_ARTIFACTS)
 
     actual_load_status = loader.load()
     assert actual_load_status["status"] == "eventful"
     assert actual_load_status["snapshot_id"] is not None
 
     assert_last_visit_matches(loader.storage, URL, status="full", type="tar")
 
     expected_revision_id = hash_to_bytes("44183488c0774ce3c957fa19ba695cf18a4a42b3")
     revision = list(loader.storage.revision_get([expected_revision_id]))[0]
 
     assert revision is not None
 
     check_metadata_paths(
         revision["metadata"],
         paths=[
             ("intrinsic", dict),
             ("extrinsic.provider", str),
             ("extrinsic.when", str),
             ("extrinsic.raw", dict),
             ("original_artifact", list),
         ],
     )
 
     for original_artifact in revision["metadata"]["original_artifact"]:
         check_metadata_paths(
             original_artifact,
             paths=[("filename", str), ("length", int), ("checksums", dict),],
         )
 
 
 def test_visit_with_release_artifact_no_prior_visit(swh_config, requests_mock_datadir):
     """With no prior visit, load a gnu project ends up with 1 snapshot
 
     """
     loader = ArchiveLoader(url=URL, artifacts=GNU_ARTIFACTS)
 
     actual_load_status = loader.load()
     assert actual_load_status["status"] == "eventful"
+
+    expected_snapshot_first_visit_id = hash_to_bytes(
+        "c419397fd912039825ebdbea378bc6283f006bf5"
+    )
+
     assert (
         hash_to_bytes(actual_load_status["snapshot_id"])
-        == _expected_new_snapshot_first_visit_id
-    )  # noqa
+        == expected_snapshot_first_visit_id
+    )
 
     assert_last_visit_matches(loader.storage, URL, status="full", type="tar")
 
     stats = get_stats(loader.storage)
     assert {
         "content": len(_expected_new_contents_first_visit),
         "directory": len(_expected_new_directories_first_visit),
         "origin": 1,
         "origin_visit": 1,
         "person": 1,
         "release": 0,
         "revision": len(_expected_new_revisions_first_visit),
         "skipped_content": 0,
         "snapshot": 1,
     } == stats
 
     expected_contents = map(hash_to_bytes, _expected_new_contents_first_visit)
     assert list(loader.storage.content_missing_per_sha1(expected_contents)) == []
 
     expected_dirs = map(hash_to_bytes, _expected_new_directories_first_visit)
     assert list(loader.storage.directory_missing(expected_dirs)) == []
 
     expected_revs = map(hash_to_bytes, _expected_new_revisions_first_visit)
     assert list(loader.storage.revision_missing(expected_revs)) == []
 
-    expected_snapshot = {
-        "id": _expected_new_snapshot_first_visit_id,
-        "branches": _expected_branches_first_visit,
-    }
+    expected_snapshot = Snapshot(
+        id=expected_snapshot_first_visit_id,
+        branches={
+            b"HEAD": SnapshotBranch(
+                target_type=TargetType.ALIAS, target=b"releases/0.1.0",
+            ),
+            b"releases/0.1.0": SnapshotBranch(
+                target_type=TargetType.REVISION,
+                target=hash_to_bytes("44183488c0774ce3c957fa19ba695cf18a4a42b3"),
+            ),
+        },
+    )
 
     check_snapshot(expected_snapshot, loader.storage)
 
 
 def test_2_visits_without_change(swh_config, requests_mock_datadir):
     """With no prior visit, load a gnu project ends up with 1 snapshot
 
     """
     url = URL
     loader = ArchiveLoader(url, artifacts=GNU_ARTIFACTS)
 
     actual_load_status = loader.load()
     assert actual_load_status["status"] == "eventful"
     assert actual_load_status["snapshot_id"] is not None
 
     assert_last_visit_matches(loader.storage, url, status="full", type="tar")
 
     actual_load_status2 = loader.load()
     assert actual_load_status2["status"] == "uneventful"
     assert actual_load_status2["snapshot_id"] is not None
     assert actual_load_status["snapshot_id"] == actual_load_status2["snapshot_id"]
 
     assert_last_visit_matches(loader.storage, url, status="full", type="tar")
 
     urls = [
         m.url
         for m in requests_mock_datadir.request_history
         if m.url.startswith("https://ftp.gnu.org")
     ]
     assert len(urls) == 1
 
 
 def test_2_visits_with_new_artifact(swh_config, requests_mock_datadir):
     """With no prior visit, load a gnu project ends up with 1 snapshot
 
     """
     url = URL
     artifact1 = GNU_ARTIFACTS[0]
     loader = ArchiveLoader(url, [artifact1])
 
     actual_load_status = loader.load()
     assert actual_load_status["status"] == "eventful"
     assert actual_load_status["snapshot_id"] is not None
 
     assert_last_visit_matches(loader.storage, url, status="full", type="tar")
 
     stats = get_stats(loader.storage)
     assert {
         "content": len(_expected_new_contents_first_visit),
         "directory": len(_expected_new_directories_first_visit),
         "origin": 1,
         "origin_visit": 1,
         "person": 1,
         "release": 0,
         "revision": len(_expected_new_revisions_first_visit),
         "skipped_content": 0,
         "snapshot": 1,
     } == stats
 
     urls = [
         m.url
         for m in requests_mock_datadir.request_history
         if m.url.startswith("https://ftp.gnu.org")
     ]
     assert len(urls) == 1
 
     artifact2 = {
         "time": 1480991830,
         "url": "https://ftp.gnu.org/gnu/8sync/8sync-0.2.0.tar.gz",
         "length": 238466,
         "filename": "8sync-0.2.0.tar.gz",
         "version": "0.2.0",
     }
 
     loader2 = ArchiveLoader(url, [artifact1, artifact2])
     # implementation detail: share the storage in between visits
     loader2.storage = loader.storage
     stats2 = get_stats(loader2.storage)
     assert stats == stats2  # ensure we share the storage
 
     actual_load_status2 = loader2.load()
     assert actual_load_status2["status"] == "eventful"
     assert actual_load_status2["snapshot_id"] is not None
 
     stats2 = get_stats(loader.storage)
     assert {
         "content": len(_expected_new_contents_first_visit) + 14,
         "directory": len(_expected_new_directories_first_visit) + 8,
         "origin": 1,
         "origin_visit": 1 + 1,
         "person": 1,
         "release": 0,
         "revision": len(_expected_new_revisions_first_visit) + 1,
         "skipped_content": 0,
         "snapshot": 1 + 1,
     } == stats2
 
     assert_last_visit_matches(loader.storage, url, status="full", type="tar")
 
     urls = [
         m.url
         for m in requests_mock_datadir.request_history
         if m.url.startswith("https://ftp.gnu.org")
     ]
     # 1 artifact (2nd time no modification) + 1 new artifact
     assert len(urls) == 2
 
 
 def test_2_visits_without_change_not_gnu(swh_config, requests_mock_datadir):
     """Load a project archive (not gnu) ends up with 1 snapshot
 
     """
     url = "https://something.else.org/8sync/"
     artifacts = [  # this is not a gnu artifact
         {
             "time": "1999-12-09T09:53:30+00:00",  # it's also not a timestamp
             "sha256": "d5d1051e59b2be6f065a9fc6aedd3a391e44d0274b78b9bb4e2b57a09134dbe4",  # noqa
             # keep a gnu artifact reference to avoid adding other test files
             "url": "https://ftp.gnu.org/gnu/8sync/8sync-0.2.0.tar.gz",
             "length": 238466,
             "filename": "8sync-0.2.0.tar.gz",
             "version": "0.2.0",
         }
     ]
 
     # Here the loader defines the id_keys to use for existence in the snapshot
     # It's not the default archive loader which
     loader = ArchiveLoader(
         url, artifacts=artifacts, identity_artifact_keys=["sha256", "length", "url"]
     )
 
     actual_load_status = loader.load()
     assert actual_load_status["status"] == "eventful"
     assert actual_load_status["snapshot_id"] is not None
     assert_last_visit_matches(loader.storage, url, status="full", type="tar")
 
     actual_load_status2 = loader.load()
     assert actual_load_status2["status"] == "uneventful"
     assert actual_load_status2["snapshot_id"] == actual_load_status["snapshot_id"]
     assert_last_visit_matches(loader.storage, url, status="full", type="tar")
 
     urls = [
         m.url
         for m in requests_mock_datadir.request_history
         if m.url.startswith("https://ftp.gnu.org")
     ]
     assert len(urls) == 1