Handle GitHub tags whose targets have no commit date

Signed-off-by: Ali Zulfiqar <codewithfourtix@gmail.com>

Author: codewithfourtix

src/fetchcode/utils.py

@@ -34,7 +34,7 @@ def fetch_github_tags_gql(purl):
 
         # in case the tag is a signed tag, then the commit info is in target['target']
         if "committedDate" not in target:
-            target = target["target"]
+            target = target.get("target") or {}
 
         committed_date = target.get("committedDate")
         release_date = None

tests/test_github_tag_targets.py

@@ -0,0 +1,11 @@
+import pytest
+
+from fetchcode import utils
+
+
+@pytest.mark.parametrize("target", [{}, {"target": {}}, {"target": None}])
+def test_tags_without_commit_targets(monkeypatch, target):
+    monkeypatch.setattr(
+        utils, "fetch_github_tag_nodes", lambda purl: [{"name": "v1", "target": target}]
+    )
+    assert list(utils.fetch_github_tags_gql(None)) == [("v1", None)]