Skip missing upload timestamps when finding PyPI release dates

src/fetchcode/package_versions.py

@@ -499,8 +499,9 @@ def get_pypi_latest_date(downloads):
     latest_date = None
     for download in downloads:
         upload_time = download.get("upload_time_iso_8601")
-        if upload_time:
-            current_date = dateparser.parse(upload_time)
+        if not upload_time:
+            continue
+        current_date = dateparser.parse(upload_time)
         if not latest_date:
             latest_date = current_date
         else:

tests/test_pypi_missing_upload_dates.py

@@ -0,0 +1,30 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+
+# This software is licensed under the Apache License version 2.0.
+
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software distributed
+# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+# CONDITIONS OF ANY KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations under the License.
+
+from fetchcode.package_versions import get_pypi_latest_date
+
+
+def test_pypi_latest_date_skips_missing_upload_times():
+    assert get_pypi_latest_date([{}, {"upload_time_iso_8601": None}]) is None
+    result = get_pypi_latest_date(
+        [
+            {},
+            {"upload_time_iso_8601": "2024-01-02T00:00:00Z"},
+            {},
+            {"upload_time_iso_8601": "2024-01-01T00:00:00Z"},
+        ]
+    )
+    assert result.isoformat() == "2024-01-02T00:00:00+00:00"