diff --git a/tests/unit/report/test_report.py b/tests/unit/report/test_report.py
index 49917eab..ac4b32ea 100644
--- a/tests/unit/report/test_report.py
+++ b/tests/unit/report/test_report.py
@@ -1,21 +1,21 @@
 # Copyright (c) 2021, INRIA
 # Copyright (c) 2021, University of Lille
 # All rights reserved.
-
+#
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
-
+#
 # * Redistributions of source code must retain the above copyright notice, this
 #   list of conditions and the following disclaimer.
-
+#
 # * Redistributions in binary form must reproduce the above copyright notice,
 #   this list of conditions and the following disclaimer in the documentation
 #   and/or other materials provided with the distribution.
-
+#
 # * Neither the name of the copyright holder nor the names of its
 #   contributors may be used to endorse or promote products derived from
 #   this software without specific prior written permission.
-
+#
 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
@@ -27,30 +27,20 @@
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-import pytest
-
-from powerapi.report import Report
 from datetime import datetime
 
-
-@pytest.fixture()
-def basic_report():
-    return Report(timestamp=datetime.strptime('1970-09-01T09:09:10.543', "%Y-%m-%dT%H:%M:%S.%f"), sensor='toto',
-                  target='all', metadata={"tag": 1})
-
-
-@pytest.fixture()
-def expected_json_report(basic_report):
-    return {'timestamp': basic_report.timestamp,
-            'sensor': basic_report.sensor,
-            'target': basic_report.target,
-            'metadata': basic_report.metadata}
+from powerapi.report import Report
 
 
 def test_creating_report_with_metadata():
-    report = Report(timestamp=datetime.strptime('1970-09-01T09:09:10.543', "%Y-%m-%dT%H:%M:%S.%f"), sensor='toto',
-                    target='all', metadata={"tag": 1})
-    assert report.metadata["tag"] == 1
+    """
+    Test creating a report with metadata.
+    """
+    report = Report(datetime.now(), 'pytest', 'test', {'tag1': 1, 'tag2': .2, 'tag3': '3'})
+
+    assert report.metadata["tag1"] == 1
+    assert report.metadata["tag2"] == .2
+    assert report.metadata["tag3"] == '3'
 
 
 def test_create_two_report_without_metadata_metadata_are_different():
@@ -65,18 +55,39 @@ def test_create_two_report_without_metadata_metadata_are_different():
     assert a.metadata != b.metadata
 
 
-def test_to_json(basic_report, expected_json_report):
-
-    json = Report.to_json(report=basic_report)
-    assert 'sender_name' not in json
-    assert 'dispatcher_report_id' not in json
-    assert json == expected_json_report
-
+def test_sanitize_tags_name():
+    """
+    Test sanitizing tag names from the metadata dictionary.
+    """
+    tags = ['test-tag', 'app.kubernetes.io/name', 'helm.sh/chart']
+    sanitized_tags = Report.sanitize_tags_name(tags)
 
-def test_to_json_with_dispatcher_report_id(basic_report, expected_json_report):
-    basic_report.dispatcher_report_id = 10
+    assert len(sanitized_tags) == len(tags)
+    assert sanitized_tags['test-tag'] == 'test_tag'
+    assert sanitized_tags['app.kubernetes.io/name'] == 'app_kubernetes_io_name'
+    assert sanitized_tags['helm.sh/chart'] == 'helm_sh_chart'
 
-    json = Report.to_json(report=basic_report)
-    assert 'sender_name' not in json
-    assert 'dispatcher_report_id' not in json
-    assert json == expected_json_report
+def test_flatten_metadata_dict():
+    """
+    Test flattening a report metadata dictionary.
+    """
+    report_metadata = {
+        'scope': 'cpu',
+        'socket': 0,
+        'formula': '0000000000000000000000000000000000000000',
+        'k8s': {
+            'app.kubernetes.io/name': 'test',
+            'app.kubernetes.io/instance': 'test-abcxyz',
+            'app.kubernetes.io/managed-by': 'pytest',
+            'helm.sh/chart': 'powerapi-pytest-1.0.0'
+        }
+    }
+    flattened_metadata = Report.flatten_tags(report_metadata)
+
+    assert flattened_metadata['scope'] == 'cpu'
+    assert flattened_metadata['socket'] == 0
+    assert flattened_metadata['formula'] == '0000000000000000000000000000000000000000'
+    assert flattened_metadata['k8s/app.kubernetes.io/name'] == 'test'
+    assert flattened_metadata['k8s/app.kubernetes.io/instance'] == 'test-abcxyz'
+    assert flattened_metadata['k8s/app.kubernetes.io/managed-by'] == 'pytest'
+    assert flattened_metadata['k8s/helm.sh/chart'] == 'powerapi-pytest-1.0.0'