Add requested_extras to installation report

Author: sbidoul

src/pip/_internal/models/installation_report.py

@@ -30,6 +30,9 @@ def _install_req_to_dict(cls, ireq: InstallRequirement) -> Dict[str, Any]:
             # https://www.python.org/dev/peps/pep-0566/#json-compatible-metadata
             "metadata": ireq.get_dist().metadata_dict,
         }
+        if ireq.user_supplied and ireq.extras:
+            # For top level requirements, the list of requested extras, if any.
+            res["requested_extras"] = list(sorted(ireq.extras))
         return res
 
     def to_dict(self) -> Dict[str, Any]:

tests/functional/test_install_report.py

@@ -85,6 +85,7 @@ def test_install_report_index(script: PipTestEnvironment, tmp_path: Path) -> Non
         paste_report["download_info"]["archive_info"]["hash"]
         == "sha256=11645842ba8ec986ae8cfbe4c6cacff5c35f0f4527abf4f5581ae8b4ad49c0b6"
     )
+    assert paste_report["requested_extras"] == ["openid"]
     assert "requires_dist" in paste_report["metadata"]