feat: ta processor handles placeholder storage

we want to be able to specify an upload that was not able to find a file
so we can make a comment on the PR letting the user know that a file
was not found.

this upload is represented using the "placeholder" storage path

services/test_results.py

@@ -244,13 +244,24 @@ def messagify_flake(
 
 def specific_error_message(upload_error: UploadError) -> str:
     title = f"### :x: {upload_error.error_code}"
-    description = "\n".join(
-        [
-            f"Upload processing failed due to {upload_error.error_code.lower()}. Please review the parser error message:",
-            f"`{upload_error.error_params['error_message']}`",
-            "For more help, visit our [troubleshooting guide](https://docs.codecov.com/docs/test-analytics#troubleshooting).",
-        ]
-    )
+    if upload_error.error_code == "Unsupported file format":
+        description = "\n".join(
+            [
+                "Upload processing failed due to unsupported file format. Please review the parser error message:",
+                f"`{upload_error.error_params['error_message']}`",
+                "For more help, visit our [troubleshooting guide](https://docs.codecov.com/docs/test-analytics#troubleshooting).",
+            ]
+        )
+    elif upload_error.error_code == "File not found":
+        description = "\n".join(
+            [
+                "No result to display due to the CLI not being able to find the file.",
+                "Please ensure the file contains `junit` in the name and automated file search is enabled,",
+                "or the desired file specified by the `file` and `search_dir` arguments of the CLI.",
+            ]
+        )
+    else:
+        raise ValueError("Unrecognized error code")
     message = [
         title,
         make_quoted(description),

tasks/ta_processor.py

@@ -89,6 +89,17 @@ def process_individual_upload(
             # don't need to process again because the intermediate result should already be in redis
             return False
 
+        if upload.storage_path == "placeholder":
+            upload.state = "v2_processed"
+            new_upload_error = UploadError(
+                upload_id=upload.id,
+                error_code="File not found",
+                error_params={},
+            )
+            db_session.add(new_upload_error)
+            db_session.commit()
+            return False
+
         payload_bytes = archive_service.read_file(upload.storage_path)
 
         try:

tasks/tests/unit/test_ta_finisher_task.py

@@ -519,3 +519,67 @@ def test_test_analytics_regular_comment_with_error(
 
     rollups = dbsession.query(DailyTestRollup).all()
     assert len(rollups) == 1
+
+
+def test_ta_file_not_found(
+    dbsession,
+    mocker,
+    mock_storage,
+    celery_app,
+    mock_repo_provider_service,
+    mock_pull_request_information,
+    generate_junit,
+):
+    mocker.patch.object(TAProcessorTask, "app", celery_app)
+    mocker.patch.object(TAFinisherTask, "app", celery_app)
+
+    commit = CommitFactory.create()
+
+    upload = generate_junit(raw="a", commit=commit)
+    upload.storage_path = "placeholder"
+    dbsession.flush()
+
+    argument = {"url": "placeholder", "upload_id": upload.id_}
+    result = TAProcessorTask().run_impl(
+        dbsession,
+        repoid=upload.report.commit.repoid,
+        commitid=upload.report.commit.commitid,
+        commit_yaml={"codecov": {"max_report_age": False}},
+        argument=argument,
+    )
+    assert result is False
+
+    result = TAFinisherTask().run_impl(
+        dbsession,
+        chord_result=[result],
+        repoid=upload.report.commit.repoid,
+        commitid=upload.report.commit.commitid,
+        commit_yaml={"codecov": {"max_report_age": False}},
+    )
+
+    assert result["notify_attempted"] is True
+    assert result["notify_succeeded"] is True
+    assert result["queue_notify"] is True
+
+    short_form_service_name = services_short_dict.get(
+        upload.report.commit.repository.owner.service
+    )
+
+    mock_repo_provider_service.edit_comment.assert_called_once()
+    mock_repo_provider_service.edit_comment.assert_called_once_with(
+        mock_pull_request_information.database_pull.pullid,
+        mock_pull_request_information.database_pull.commentid,
+        """### :x: File not found
+
+> No result to display due to the CLI not being able to find the file.
+> Please ensure the file contains `junit` in the name and automated file search is enabled,
+> or the desired file specified by the `file` and `search_dir` arguments of the CLI.
+""",
+    )
+
+    tests = dbsession.query(Test).all()
+    assert len(tests) == 0
+    test_instances = dbsession.query(TestInstance).all()
+    assert len(test_instances) == 0
+    rollups = dbsession.query(DailyTestRollup).all()
+    assert len(rollups) == 0