delete outdated comments

.github/workflows/lintAndFormat.yml

@@ -28,6 +28,18 @@ jobs:
           fetch-depth: 2
           submodules: "true"
 
+      # garbage collect old comments
+      - name: Delete old comments
+        env:
+          GITHUB_PR_NUMBER: ${{ github.event.pull_request.number }}
+        run: |
+          PULL_REQUEST_ID="$(jq "if (.issue.number != null) then .issue.number else .number end" < "$GITHUB_EVENT_PATH")"
+          echo $PULL_REQUEST_ID
+          
+          GITHUB_TOKEN=${{ secrets.GITHUB_TOKEN }}  python utils/git/delete_outdated_comments.py \
+          --repository "$GITHUB_REPOSITORY" \
+          --pull-number "$PULL_REQUEST_ID"
+
       - name: Install clang-tidy
         run: |
           sudo apt-get update

utils/git/delete_outdated_comments.py

@@ -0,0 +1,86 @@
+import argparse
+import json
+import os
+import sys
+
+import requests
+
+
+def get_pull_request_comments(
+    github_api_url, github_token, github_api_timeout, repo, pull_number
+):
+    for page in range(1, 100):
+        result = requests.get(
+            f"{github_api_url}/repos/{repo}/pulls/{pull_number:d}/comments?page={page:d}",
+            headers={
+                "Accept": "application/vnd.github.v3+json",
+                "Authorization": f"token {github_token}",
+            },
+            timeout=github_api_timeout,
+        )
+
+        assert result.status_code == requests.codes.ok  # pylint: disable=no-member
+
+        chunk = json.loads(result.text)
+
+        if len(chunk) == 0:
+            break
+
+        for item in chunk:
+            yield item
+
+
+def delete_pull_request_comment(
+    github_api_url, github_token, github_api_timeout, repo, comment_id
+):
+    result = requests.get(
+        f"{github_api_url}/repos/{repo}/pulls/comments/{comment_id}",
+        headers={
+            "Accept": "application/vnd.github.v3+json",
+            "Authorization": f"token {github_token}",
+        },
+        timeout=github_api_timeout,
+    )
+
+    assert result.status_code == requests.codes.ok  # pylint: disable=no-member
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--repository",
+        type=str,
+        required=True,
+        help="Name of the repository containing the code",
+    )
+    parser.add_argument(
+        "--pull-number",
+        type=int,
+        required=True,
+    )
+    args = parser.parse_args()
+
+    # The GitHub API token is sensitive information, pass it through the environment
+    github_token = os.environ.get("GITHUB_TOKEN")
+    github_api_url = os.environ.get("GITHUB_API_URL")
+    github_api_timeout = 10
+
+    for comment in get_pull_request_comments(
+        github_api_url,
+        github_token,
+        github_api_timeout,
+        args.repository,
+        args.pull_number,
+    ):
+        if comment["user"]["login"] == "github-actions[bot]":
+            delete_pull_request_comment(
+                github_api_url,
+                github_token,
+                github_api_timeout,
+                args.repository,
+                comment["id"],
+            )
+
+
+if __name__ == "__main__":
+    sys.exit(main())