diff --git a/swh/model/tests/test_hashutil.py b/swh/model/tests/test_hashutil.py
--- a/swh/model/tests/test_hashutil.py
+++ b/swh/model/tests/test_hashutil.py
@@ -8,9 +8,10 @@
 import io
 import os
 import tempfile
-import unittest
 from unittest.mock import patch
 
+import pytest
+
 from swh.model import hashutil
 from swh.model.hashutil import MultiHash
 
@@ -26,13 +27,16 @@
         hashutil._blake2_hash_cache.clear()
 
 
-class BaseHashutil(unittest.TestCase):
-    def setUp(self):
-        # Reset function cache
-        hashutil._blake2_hash_cache = {}
+@pytest.fixture
+def hash_test_data():
+
+    # Reset function cache
+    hashutil._blake2_hash_cache = {}
+
+    class HashTestData:
 
-        self.data = b"1984\n"
-        self.hex_checksums = {
+        data = b"1984\n"
+        hex_checksums = {
             "sha1": "62be35bf00ff0c624f4a621e2ea5595a049e0731",
             "sha1_git": "568aaf43d83b2c3df8067f3bedbb97d83260be6d",
             "sha256": "26602113b4b9afd9d55466b08580d3c2"
@@ -41,238 +45,252 @@
             "c9422f9f2dc8906",
         }
 
-        self.checksums = {
-            type: bytes.fromhex(cksum) for type, cksum in self.hex_checksums.items()
+        checksums = {
+            type: bytes.fromhex(cksum) for type, cksum in hex_checksums.items()
         }
 
-        self.bytehex_checksums = {
-            type: hashutil.hash_to_bytehex(cksum)
-            for type, cksum in self.checksums.items()
+        bytehex_checksums = {
+            type: hashutil.hash_to_bytehex(cksum) for type, cksum in checksums.items()
         }
 
-        self.git_hex_checksums = {
-            "blob": self.hex_checksums["sha1_git"],
+        git_hex_checksums = {
+            "blob": hex_checksums["sha1_git"],
             "tree": "5b2e883aa33d2efab98442693ea4dd5f1b8871b0",
             "commit": "79e4093542e72f0fcb7cbd75cb7d270f9254aa8f",
             "tag": "d6bf62466f287b4d986c545890716ce058bddf67",
         }
 
-        self.git_checksums = {
-            type: bytes.fromhex(cksum) for type, cksum in self.git_hex_checksums.items()
+        git_checksums = {
+            type: bytes.fromhex(cksum) for type, cksum in git_hex_checksums.items()
         }
 
+    return HashTestData
 
-class MultiHashTest(BaseHashutil):
-    def test_multi_hash_data(self):
-        checksums = MultiHash.from_data(self.data).digest()
-        self.assertEqual(checksums, self.checksums)
-        self.assertFalse("length" in checksums)
 
-    def test_multi_hash_data_with_length(self):
-        expected_checksums = self.checksums.copy()
-        expected_checksums["length"] = len(self.data)
+def test_multi_hash_data(hash_test_data):
+    checksums = MultiHash.from_data(hash_test_data.data).digest()
+    assert checksums == hash_test_data.checksums
+    assert "length" not in checksums
 
-        algos = set(["length"]).union(hashutil.DEFAULT_ALGORITHMS)
-        checksums = MultiHash.from_data(self.data, hash_names=algos).digest()
 
-        self.assertEqual(checksums, expected_checksums)
-        self.assertTrue("length" in checksums)
+def test_multi_hash_data_with_length(hash_test_data):
+    expected_checksums = hash_test_data.checksums.copy()
+    expected_checksums["length"] = len(hash_test_data.data)
 
-    def test_multi_hash_data_unknown_hash(self):
-        with self.assertRaises(ValueError) as cm:
-            MultiHash.from_data(self.data, ["unknown-hash"])
+    algos = set(["length"]).union(hashutil.DEFAULT_ALGORITHMS)
+    checksums = MultiHash.from_data(hash_test_data.data, hash_names=algos).digest()
 
-        self.assertIn("Unexpected hashing algorithm", cm.exception.args[0])
-        self.assertIn("unknown-hash", cm.exception.args[0])
+    assert checksums == expected_checksums
+    assert "length" in checksums
 
-    def test_multi_hash_file(self):
-        fobj = io.BytesIO(self.data)
 
-        checksums = MultiHash.from_file(fobj, length=len(self.data)).digest()
-        self.assertEqual(checksums, self.checksums)
+def test_multi_hash_data_unknown_hash(hash_test_data):
+    with pytest.raises(ValueError, match="Unexpected hashing algorithm.*unknown-hash"):
+        MultiHash.from_data(hash_test_data.data, ["unknown-hash"])
 
-    def test_multi_hash_file_hexdigest(self):
-        fobj = io.BytesIO(self.data)
-        length = len(self.data)
-        checksums = MultiHash.from_file(fobj, length=length).hexdigest()
-        self.assertEqual(checksums, self.hex_checksums)
 
-    def test_multi_hash_file_bytehexdigest(self):
-        fobj = io.BytesIO(self.data)
-        length = len(self.data)
-        checksums = MultiHash.from_file(fobj, length=length).bytehexdigest()
-        self.assertEqual(checksums, self.bytehex_checksums)
+def test_multi_hash_file(hash_test_data):
+    fobj = io.BytesIO(hash_test_data.data)
 
-    def test_multi_hash_file_missing_length(self):
-        fobj = io.BytesIO(self.data)
-        with self.assertRaises(ValueError) as cm:
-            MultiHash.from_file(fobj, hash_names=["sha1_git"])
+    checksums = MultiHash.from_file(fobj, length=len(hash_test_data.data)).digest()
+    assert checksums == hash_test_data.checksums
 
-        self.assertIn("Missing length", cm.exception.args[0])
 
-    def test_multi_hash_path(self):
-        with tempfile.NamedTemporaryFile(delete=False) as f:
-            f.write(self.data)
+def test_multi_hash_file_hexdigest(hash_test_data):
+    fobj = io.BytesIO(hash_test_data.data)
+    length = len(hash_test_data.data)
+    checksums = MultiHash.from_file(fobj, length=length).hexdigest()
+    assert checksums == hash_test_data.hex_checksums
 
-        hashes = MultiHash.from_path(f.name).digest()
-        os.remove(f.name)
 
-        self.assertEqual(self.checksums, hashes)
+def test_multi_hash_file_bytehexdigest(hash_test_data):
+    fobj = io.BytesIO(hash_test_data.data)
+    length = len(hash_test_data.data)
+    checksums = MultiHash.from_file(fobj, length=length).bytehexdigest()
+    assert checksums == hash_test_data.bytehex_checksums
 
 
-class Hashutil(BaseHashutil):
-    def test_hash_git_data(self):
-        checksums = {
-            git_type: hashutil.hash_git_data(self.data, git_type)
-            for git_type in self.git_checksums
-        }
+def test_multi_hash_file_missing_length(hash_test_data):
+    fobj = io.BytesIO(hash_test_data.data)
+    with pytest.raises(ValueError, match="Missing length"):
+        MultiHash.from_file(fobj, hash_names=["sha1_git"])
 
-        self.assertEqual(checksums, self.git_checksums)
-
-    def test_hash_git_data_unknown_git_type(self):
-        with self.assertRaises(ValueError) as cm:
-            hashutil.hash_git_data(self.data, "unknown-git-type")
-
-        self.assertIn("Unexpected git object type", cm.exception.args[0])
-        self.assertIn("unknown-git-type", cm.exception.args[0])
-
-    def test_hash_to_hex(self):
-        for type in self.checksums:
-            hex = self.hex_checksums[type]
-            hash = self.checksums[type]
-            self.assertEqual(hashutil.hash_to_hex(hex), hex)
-            self.assertEqual(hashutil.hash_to_hex(hash), hex)
-
-    def test_hash_to_bytes(self):
-        for type in self.checksums:
-            hex = self.hex_checksums[type]
-            hash = self.checksums[type]
-            self.assertEqual(hashutil.hash_to_bytes(hex), hash)
-            self.assertEqual(hashutil.hash_to_bytes(hash), hash)
-
-    def test_hash_to_bytehex(self):
-        for algo in self.checksums:
-            self.assertEqual(
-                self.hex_checksums[algo].encode("ascii"),
-                hashutil.hash_to_bytehex(self.checksums[algo]),
-            )
-
-    def test_bytehex_to_hash(self):
-        for algo in self.checksums:
-            self.assertEqual(
-                self.checksums[algo],
-                hashutil.bytehex_to_hash(self.hex_checksums[algo].encode()),
-            )
-
-    def test_new_hash_unsupported_hashing_algorithm(self):
-        try:
-            hashutil._new_hash("blake2:10")
-        except ValueError as e:
-            self.assertEqual(
-                str(e),
-                "Unexpected hashing algorithm blake2:10, "
-                "expected one of blake2b512, blake2s256, "
-                "sha1, sha1_git, sha256",
-            )
-
-    @patch("hashlib.new")
-    def test_new_hash_blake2b_blake2b512_builtin(self, mock_hashlib_new):
-        if "blake2b512" not in hashlib.algorithms_available:
-            self.skipTest("blake2b512 not built-in")
-        mock_hashlib_new.return_value = sentinel = object()
 
-        h = hashutil._new_hash("blake2b512")
+def test_multi_hash_path(hash_test_data):
+    with tempfile.NamedTemporaryFile(delete=False) as f:
+        f.write(hash_test_data.data)
 
-        self.assertIs(h, sentinel)
-        mock_hashlib_new.assert_called_with("blake2b512")
+    hashes = MultiHash.from_path(f.name).digest()
+    os.remove(f.name)
 
-    @patch("hashlib.new")
-    def test_new_hash_blake2s_blake2s256_builtin(self, mock_hashlib_new):
-        if "blake2s256" not in hashlib.algorithms_available:
-            self.skipTest("blake2s256 not built-in")
-        mock_hashlib_new.return_value = sentinel = object()
+    assert hash_test_data.checksums == hashes
 
-        h = hashutil._new_hash("blake2s256")
 
-        self.assertIs(h, sentinel)
-        mock_hashlib_new.assert_called_with("blake2s256")
+def test_hash_git_data(hash_test_data):
+    checksums = {
+        git_type: hashutil.hash_git_data(hash_test_data.data, git_type)
+        for git_type in hash_test_data.git_checksums
+    }
+
+    assert checksums == hash_test_data.git_checksums
 
-    def test_new_hash_blake2b_builtin(self):
-        removed_hash = False
 
-        try:
-            if "blake2b512" in hashlib.algorithms_available:
-                removed_hash = True
-                hashlib.algorithms_available.remove("blake2b512")
-            if "blake2b" not in hashlib.algorithms_available:
-                self.skipTest("blake2b not built in")
+def test_hash_git_data_unknown_git_type(hash_test_data):
+    with pytest.raises(
+        ValueError, match="Unexpected git object type.*unknown-git-type"
+    ):
+        hashutil.hash_git_data(hash_test_data.data, "unknown-git-type")
 
-            with patch_blake2("hashlib.blake2b") as mock_blake2b:
-                mock_blake2b.return_value = sentinel = object()
 
-                h = hashutil._new_hash("blake2b512")
+def test_hash_to_hex(hash_test_data):
+    for type in hash_test_data.checksums:
+        hex = hash_test_data.hex_checksums[type]
+        hash = hash_test_data.checksums[type]
+        assert hashutil.hash_to_hex(hex) == hex
+        assert hashutil.hash_to_hex(hash) == hex
 
-                self.assertIs(h, sentinel)
-                mock_blake2b.assert_called_with(digest_size=512 // 8)
-        finally:
-            if removed_hash:
-                hashlib.algorithms_available.add("blake2b512")
 
-    def test_new_hash_blake2s_builtin(self):
-        removed_hash = False
+def test_hash_to_bytes(hash_test_data):
+    for type in hash_test_data.checksums:
+        hex = hash_test_data.hex_checksums[type]
+        hash = hash_test_data.checksums[type]
+        assert hashutil.hash_to_bytes(hex) == hash
+        assert hashutil.hash_to_bytes(hash) == hash
 
-        try:
-            if "blake2s256" in hashlib.algorithms_available:
-                removed_hash = True
-                hashlib.algorithms_available.remove("blake2s256")
-            if "blake2s" not in hashlib.algorithms_available:
-                self.skipTest("blake2s not built in")
 
-            with patch_blake2("hashlib.blake2s") as mock_blake2s:
-                mock_blake2s.return_value = sentinel = object()
+def test_hash_to_bytehex(hash_test_data):
+    for algo in hash_test_data.checksums:
+        hex_checksum = hash_test_data.hex_checksums[algo].encode("ascii")
+        assert hex_checksum == hashutil.hash_to_bytehex(hash_test_data.checksums[algo])
+
+
+def test_bytehex_to_hash(hash_test_data):
+    for algo in hash_test_data.checksums:
+        assert hash_test_data.checksums[algo] == hashutil.bytehex_to_hash(
+            hash_test_data.hex_checksums[algo].encode()
+        )
 
-                h = hashutil._new_hash("blake2s256")
 
-                self.assertIs(h, sentinel)
-                mock_blake2s.assert_called_with(digest_size=256 // 8)
-        finally:
-            if removed_hash:
-                hashlib.algorithms_available.add("blake2s256")
+def test_new_hash_unsupported_hashing_algorithm():
+    expected_message = (
+        "Unexpected hashing algorithm blake2:10, "
+        "expected one of blake2b512, blake2s256, "
+        "sha1, sha1_git, sha256"
+    )
+    with pytest.raises(ValueError, match=expected_message):
+        hashutil._new_hash("blake2:10")
 
-    def test_new_hash_blake2b_pyblake2(self):
+
+@pytest.mark.skipif(
+    "blake2b512" not in hashlib.algorithms_available, reason="blake2b512 not built-in"
+)
+@patch("hashlib.new")
+def test_new_hash_blake2b_blake2b512_builtin(mock_hashlib_new):
+    mock_hashlib_new.return_value = sentinel = object()
+
+    h = hashutil._new_hash("blake2b512")
+
+    assert h is sentinel
+    mock_hashlib_new.assert_called_with("blake2b512")
+
+
+@pytest.mark.skipif(
+    "blake2s256" not in hashlib.algorithms_available, reason="blake2s256 not built-in"
+)
+@patch("hashlib.new")
+def test_new_hash_blake2s_blake2s256_builtin(mock_hashlib_new):
+    mock_hashlib_new.return_value = sentinel = object()
+
+    h = hashutil._new_hash("blake2s256")
+
+    assert h is sentinel
+    mock_hashlib_new.assert_called_with("blake2s256")
+
+
+@pytest.mark.skipif(
+    "blake2b" not in hashlib.algorithms_available, reason="blake2b not built-in"
+)
+def test_new_hash_blake2b_builtin(hash_test_data):
+    removed_hash = False
+
+    try:
         if "blake2b512" in hashlib.algorithms_available:
-            self.skipTest("blake2b512 built in")
-        if "blake2b" in hashlib.algorithms_available:
-            self.skipTest("blake2b built in")
+            removed_hash = True
+            hashlib.algorithms_available.remove("blake2b512")
 
-        with patch_blake2("pyblake2.blake2b") as mock_blake2b:
+        with patch_blake2("hashlib.blake2b") as mock_blake2b:
             mock_blake2b.return_value = sentinel = object()
 
             h = hashutil._new_hash("blake2b512")
 
-            self.assertIs(h, sentinel)
+            assert h is sentinel
             mock_blake2b.assert_called_with(digest_size=512 // 8)
+    finally:
+        if removed_hash:
+            hashlib.algorithms_available.add("blake2b512")
+
+
+@pytest.mark.skipif(
+    "blake2s" not in hashlib.algorithms_available, reason="blake2s not built-in"
+)
+def test_new_hash_blake2s_builtin():
+    removed_hash = False
 
-    def test_new_hash_blake2s_pyblake2(self):
+    try:
         if "blake2s256" in hashlib.algorithms_available:
-            self.skipTest("blake2s256 built in")
-        if "blake2s" in hashlib.algorithms_available:
-            self.skipTest("blake2s built in")
+            removed_hash = True
+            hashlib.algorithms_available.remove("blake2s256")
 
-        with patch_blake2("pyblake2.blake2s") as mock_blake2s:
+        with patch_blake2("hashlib.blake2s") as mock_blake2s:
             mock_blake2s.return_value = sentinel = object()
 
             h = hashutil._new_hash("blake2s256")
 
-            self.assertIs(h, sentinel)
+            assert h is sentinel
             mock_blake2s.assert_called_with(digest_size=256 // 8)
+    finally:
+        if removed_hash:
+            hashlib.algorithms_available.add("blake2s256")
+
+
+@pytest.mark.skipif(
+    "blake2b512" in hashlib.algorithms_available, reason="blake2b512 built-in"
+)
+@pytest.mark.skipif(
+    "blake2b" in hashlib.algorithms_available, reason="blake2b built-in"
+)
+def test_new_hash_blake2b_pyblake2():
+    with patch_blake2("pyblake2.blake2b") as mock_blake2b:
+        mock_blake2b.return_value = sentinel = object()
+
+        h = hashutil._new_hash("blake2b512")
+
+        assert h is sentinel
+        mock_blake2b.assert_called_with(digest_size=512 // 8)
+
 
+@pytest.mark.skipif(
+    "blake2s256" in hashlib.algorithms_available, reason="blake2s256 built-in"
+)
+@pytest.mark.skipif(
+    "blake2s" in hashlib.algorithms_available, reason="blake2s built-in"
+)
+def test_new_hash_blake2s_pyblake2():
+    with patch_blake2("pyblake2.blake2s") as mock_blake2s:
+        mock_blake2s.return_value = sentinel = object()
+
+        h = hashutil._new_hash("blake2s256")
+
+        assert h is sentinel
+        mock_blake2s.assert_called_with(digest_size=256 // 8)
 
-class HashlibGit(unittest.TestCase):
-    def setUp(self):
-        self.blob_data = b"42\n"
 
-        self.tree_data = b"".join(
+@pytest.fixture
+def hashgit_test_data():
+    class HashGitTestData:
+        blob_data = b"42\n"
+
+        tree_data = b"".join(
             [
                 b"40000 barfoo\0",
                 bytes.fromhex("c3020f6bf135a38c6df" "3afeb5fb38232c5e07087"),
@@ -283,14 +301,15 @@
             ]
         )
 
-        self.commit_data = b"""\
+        commit_data = b"""\
 tree 1c61f7259dcb770f46b194d941df4f08ff0a3970
 author Antoine R. Dumont (@ardumont) <antoine.romain.dumont@gmail.com> 1444054085 +0200
 committer Antoine R. Dumont (@ardumont) <antoine.romain.dumont@gmail.com> 1444054085 +0200
 
 initial
 """  # noqa
-        self.tag_data = """object 24d012aaec0bc5a4d2f62c56399053d6cc72a241
+
+        tag_data = """object 24d012aaec0bc5a4d2f62c56399053d6cc72a241
 type commit
 tag 0.0.1
 tagger Antoine R. Dumont (@ardumont) <antoine.romain.dumont@gmail.com> 1444225145 +0200
@@ -300,7 +319,7 @@
             "utf-8"
         )  # NOQA
 
-        self.checksums = {
+        checksums = {
             "blob_sha1_git": bytes.fromhex(
                 "d81cc0710eb6cf9efd5b920a8453e1" "e07157b6cd"
             ),
@@ -315,36 +334,43 @@
             ),
         }
 
-    def test_unknown_header_type(self):
-        with self.assertRaises(ValueError) as cm:
-            hashutil.hash_git_data(b"any-data", "some-unknown-type")
+    return HashGitTestData
+
+
+def test_unknown_header_type():
+    with pytest.raises(ValueError, match="Unexpected git object type"):
+        hashutil.hash_git_data(b"any-data", "some-unknown-type")
+
+
+def test_hashdata_content(hashgit_test_data):
+    # when
+    actual_hash = hashutil.hash_git_data(hashgit_test_data.blob_data, git_type="blob")
+
+    # then
+    assert actual_hash == hashgit_test_data.checksums["blob_sha1_git"]
 
-        self.assertIn("Unexpected git object type", cm.exception.args[0])
 
-    def test_hashdata_content(self):
-        # when
-        actual_hash = hashutil.hash_git_data(self.blob_data, git_type="blob")
+def test_hashdata_tree(hashgit_test_data):
+    # when
+    actual_hash = hashutil.hash_git_data(hashgit_test_data.tree_data, git_type="tree")
 
-        # then
-        self.assertEqual(actual_hash, self.checksums["blob_sha1_git"])
+    # then
+    assert actual_hash == hashgit_test_data.checksums["tree_sha1_git"]
 
-    def test_hashdata_tree(self):
-        # when
-        actual_hash = hashutil.hash_git_data(self.tree_data, git_type="tree")
 
-        # then
-        self.assertEqual(actual_hash, self.checksums["tree_sha1_git"])
+def test_hashdata_revision(hashgit_test_data):
+    # when
+    actual_hash = hashutil.hash_git_data(
+        hashgit_test_data.commit_data, git_type="commit"
+    )
 
-    def test_hashdata_revision(self):
-        # when
-        actual_hash = hashutil.hash_git_data(self.commit_data, git_type="commit")
+    # then
+    assert actual_hash == hashgit_test_data.checksums["commit_sha1_git"]
 
-        # then
-        self.assertEqual(actual_hash, self.checksums["commit_sha1_git"])
 
-    def test_hashdata_tag(self):
-        # when
-        actual_hash = hashutil.hash_git_data(self.tag_data, git_type="tag")
+def test_hashdata_tag(hashgit_test_data):
+    # when
+    actual_hash = hashutil.hash_git_data(hashgit_test_data.tag_data, git_type="tag")
 
-        # then
-        self.assertEqual(actual_hash, self.checksums["tag_sha1_git"])
+    # then
+    assert actual_hash == hashgit_test_data.checksums["tag_sha1_git"]