diff --git a/swh/indexer/tests/test_metadata.py b/swh/indexer/tests/test_metadata.py
--- a/swh/indexer/tests/test_metadata.py
+++ b/swh/indexer/tests/test_metadata.py
@@ -16,11 +16,20 @@
 )
 
 from .test_utils import (
-    MockObjStorage, MockStorage, MockIndexerStorage,
-    BASE_TEST_CONFIG
+    BASE_TEST_CONFIG, fill_obj_storage, fill_storage
 )
 
 
+TRANSLATOR_TOOL = {
+    'name': 'swh-metadata-translator',
+    'version': '0.0.2',
+    'configuration': {
+        'type': 'local',
+        'context': 'NpmMapping'
+    }
+}
+
+
 class ContentMetadataTestIndexer(ContentMetadataIndexer):
     """Specific Metadata whose configuration is enough to satisfy the
        indexing tests.
@@ -30,8 +39,6 @@
 
     def prepare(self):
         super().prepare()
-        self.objstorage = MockObjStorage()
-        self.idx_storage = MockIndexerStorage()
 
 
 class RevisionMetadataTestIndexer(RevisionMetadataIndexer):
@@ -44,21 +51,11 @@
     def parse_config_file(self, *args, **kwargs):
         return {
             **BASE_TEST_CONFIG,
-            'tools': {
-                'name': 'swh-metadata-detector',
-                'version': '0.0.2',
-                'configuration': {
-                    'type': 'local',
-                    'context': 'NpmMapping'
-                }
-            }
+            'tools': TRANSLATOR_TOOL,
         }
 
     def prepare(self):
         super().prepare()
-        self.storage = MockStorage()
-        self.idx_storage = MockIndexerStorage()
-        self.objstorage = MockObjStorage()
         self.tools = list(self.register_tools(self.config['tools']))
 
 
@@ -71,15 +68,6 @@
         shows the entire diff in the results
         """
         self.maxDiff = None
-        self.content_tool = {
-            'name': 'swh-metadata-translator',
-            'version': '0.0.2',
-            'configuration': {
-                'type': 'local',
-                'context': 'NpmMapping'
-            }
-        }
-        MockIndexerStorage.added_data = []
 
     def test_crosstable(self):
         self.assertEqual(CROSSWALK_TABLE['NodeJS'], {
@@ -204,19 +192,24 @@
           should return None in the translated metadata
         """
         # given
-        sha1s = ['26a9f72a7c87cc9205725cfd879f514ff4f3d8d5',
-                 'd4c647f0fc257591cc9ba1722484229780d1c607',
-                 '02fb2c89e14f7fab46701478c83779c7beb7b069']
+        sha1s = [
+            hash_to_bytes('26a9f72a7c87cc9205725cfd879f514ff4f3d8d5'),
+            hash_to_bytes('d4c647f0fc257591cc9ba1722484229780d1c607'),
+            hash_to_bytes('02fb2c89e14f7fab46701478c83779c7beb7b069'),
+        ]
         # this metadata indexer computes only metadata for package.json
         # in npm context with a hard mapping
         metadata_indexer = ContentMetadataTestIndexer(
-            tool=self.content_tool, config=BASE_TEST_CONFIG.copy())
+            tool=TRANSLATOR_TOOL, config=BASE_TEST_CONFIG.copy())
+        fill_obj_storage(metadata_indexer.objstorage)
+        fill_storage(metadata_indexer.storage)
 
         # when
         metadata_indexer.run(sha1s, policy_update='ignore-dups')
-        results = metadata_indexer.idx_storage.added_data
+        results = list(metadata_indexer.idx_storage.content_metadata_get(
+            sha1s))
 
-        expected_results = [('content_metadata', False, [{
+        expected_results = [{
             'translated_metadata': {
                 '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
                 'type': 'SoftwareSourceCode',
@@ -226,7 +219,7 @@
                 'name': 'test_metadata',
                 'version': '0.0.1'
             },
-            'id': '26a9f72a7c87cc9205725cfd879f514ff4f3d8d5'
+            'id': hash_to_bytes('26a9f72a7c87cc9205725cfd879f514ff4f3d8d5')
             }, {
             'translated_metadata': {
                 '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
@@ -253,16 +246,14 @@
                 ],
                 'schema:url': 'https://docs.npmjs.com/'
             },
-            'id': 'd4c647f0fc257591cc9ba1722484229780d1c607'
+            'id': hash_to_bytes('d4c647f0fc257591cc9ba1722484229780d1c607')
             }, {
             'translated_metadata': None,
-            'id': '02fb2c89e14f7fab46701478c83779c7beb7b069'
-        }])]
+            'id': hash_to_bytes('02fb2c89e14f7fab46701478c83779c7beb7b069')
+        }]
 
         for result in results:
-            metadata = result[2]
-            for item in metadata:
-                del item['indexer_configuration_id']
+            del result['tool']
 
         # The assertion below returns False sometimes because of nested lists
         self.assertEqual(expected_results, results)
@@ -449,16 +440,47 @@
 
     def test_revision_metadata_indexer(self):
         metadata_indexer = RevisionMetadataTestIndexer()
+        fill_obj_storage(metadata_indexer.objstorage)
+        fill_storage(metadata_indexer.storage)
+
+        tool = metadata_indexer.idx_storage.indexer_configuration_get(
+            {'tool_'+k: v for (k, v) in TRANSLATOR_TOOL.items()})
+        assert tool is not None
+
+        metadata_indexer.idx_storage.content_metadata_add([{
+            'indexer_configuration_id': tool['id'],
+            'id': b'cde',
+            'translated_metadata': {
+                '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
+                'type': 'SoftwareSourceCode',
+                'codemeta:issueTracker':
+                    'https://github.com/librariesio/yarn-parser/issues',
+                'version': '1.0.0',
+                'name': 'yarn-parser',
+                'schema:author': 'Andrew Nesbitt',
+                'url':
+                    'https://github.com/librariesio/yarn-parser#readme',
+                'processorRequirements': {'node': '7.5'},
+                'license': 'AGPL-3.0',
+                'keywords': ['yarn', 'parse', 'lock', 'dependencies'],
+                'schema:codeRepository':
+                    'git+https://github.com/librariesio/yarn-parser.git',
+                'description':
+                    'Tiny web service for parsing yarn.lock files',
+                }
+        }])
 
         sha1_gits = [
             hash_to_bytes('8dbb6aeb036e7fd80664eb8bfd1507881af1ba9f'),
         ]
         metadata_indexer.run(sha1_gits, 'update-dups')
 
-        results = metadata_indexer.idx_storage.added_data
+        results = list(metadata_indexer.idx_storage.revision_metadata_get(
+            sha1_gits))
 
-        expected_results = [('revision_metadata', True, [{
+        expected_results = [{
             'id': hash_to_bytes('8dbb6aeb036e7fd80664eb8bfd1507881af1ba9f'),
+            'tool': TRANSLATOR_TOOL,
             'translated_metadata': {
                 '@context': 'https://doi.org/10.5063/schema/codemeta-2.0',
                 'url':
@@ -475,12 +497,10 @@
                 'name': 'yarn-parser',
                 'keywords': ['yarn', 'parse', 'lock', 'dependencies'],
             },
-        }])]
+        }]
 
         for result in results:
-            metadata = result[2]
-            for item in metadata:
-                del item['indexer_configuration_id']
+            del result['tool']['id']
 
         # then
         self.assertEqual(expected_results, results)