CI: don't upload comment/ID artifact if no existing comment

Author: Jami Cogswell

.github/workflows/csv-coverage-pr-artifacts.yml

@@ -99,10 +99,16 @@ jobs:
           path: pr/
       - name: Save comment ID (if it exists)
         run: |
-          mkdir -p comment
           # Find the latest comment starting with COMMENT_PREFIX
           COMMENT_PREFIX=":warning: The head of this PR and the base branch were compared for differences in the framework coverage reports."
-          gh api "repos/${GITHUB_REPOSITORY}/issues/${PR_NUMBER}/comments" --paginate | jq --arg prefix "${COMMENT_PREFIX}" '[.[] | select(.body|startswith($prefix)) | .id] | max' > comment/ID
+          COMMENT_ID=$(gh api "repos/${GITHUB_REPOSITORY}/issues/${PR_NUMBER}/comments" --paginate | jq --arg prefix "${COMMENT_PREFIX}" 'map(select(.body|startswith($prefix)) | .id) | max // empty')
+          if [[ -z ${COMMENT_ID} ]]
+          then
+            echo "Comment not found. Not uploading 'comment/ID' artifact."
+          else
+            mkdir -p comment
+            echo ${COMMENT_ID} > comment/ID
+          fi
         env:
           GITHUB_TOKEN: ${{ github.token }}
           PR_NUMBER: ${{ github.event.pull_request.number }}
@@ -111,3 +117,4 @@ jobs:
         with:
           name: comment
           path: comment/
+          if-no-files-found: ignore

misc/scripts/library-coverage/comment-pr.py

@@ -56,14 +56,13 @@ def comment_pr(repo, run_id):
         if os.path.isdir("pr"):
             shutil.rmtree("pr")
 
-    utils.download_artifact(repo, "comment", "comment", run_id)
-
     try:
+        utils.download_artifact(repo, "comment", "comment", run_id)
         with open("comment/ID") as file:
             raw_comment_id = int(file.read())
     except Exception as e:
-        # If there is no existing comment, comment/ID will contain just a
-        # newline (due to jq & gh behaviour). This will cause `int(file.read())`
+        # If there is no existing comment, the `comment/ID` artifact
+        # will not exist. This will cause `utils.download_artifact`
         # to fail, so we catch that and set `raw_comment_id` to `None`.
         print("Could not retrieve an existing comment ID. \n", e)
         raw_comment_id = None