From 3a712cc5027b0e08216882af83ef4096efc0627a Mon Sep 17 00:00:00 2001
From: R script <martin.smith@durham.ac.uk>
Date: Thu, 20 Aug 2026 11:59:19 +0100
Subject: [PATCH] Collapse superseded benchmark comments rather than prefixing
 them

The step already tracked which of its own comments were stale; it just had
no way to act on it beyond prepending a warning banner, which left every
old result at full height. GitHub's `minimizeComment` mutation with
`classifier: OUTDATED` is the real thing -- the comment folds into the
collapsed "marked as outdated" state.

Listing moves to GraphQL out of necessity, not taste: REST's comment
payload omits `isMinimized`, and since minimizing no longer touches the
body, that flag is the only remaining idempotency guard. Without it every
run would re-minimize the whole history.

Neither half may throw. The step exists to post the new result, and losing
that to a hiccup in tidying up the old ones would be a poor trade -- so a
failed listing or a failed collapse warns and the comment still lands. The
likeliest such failure is a token without the scope `minimizeComment`
needs. This job declares no `permissions:` block, so it runs on the
repository default; if the warning fires, that is where to look.

Comments already carrying the old banner keep it, and will be collapsed
banner-and-all on the next run.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
---
 .github/workflows/R-CMD-check.yml | 63 ++++++++++++++++++++++---------
 1 file changed, 46 insertions(+), 17 deletions(-)

diff --git a/.github/workflows/R-CMD-check.yml b/.github/workflows/R-CMD-check.yml
index 27a059f8..d31c33b1 100644
--- a/.github/workflows/R-CMD-check.yml
+++ b/.github/workflows/R-CMD-check.yml
@@ -330,29 +330,58 @@ jobs:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           script: |
             const benchmarkIdentifier = '<!-- benchmark-comment -->';
-            const outdatedPrefix = '> **⚠️ This benchmark result is outdated. See the latest comment below.**\n\n';
 
-            const comments = await github.rest.issues.listComments({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              issue_number: context.issue.number
-            });
-
-            const previousBenchmarkComments = comments.data.filter(comment =>
-              comment.user.type === 'Bot' &&
-              comment.body.includes(benchmarkIdentifier) &&
-              !comment.body.startsWith('> **⚠️ This benchmark result is outdated.')
-            );
-
-            for (const comment of previousBenchmarkComments) {
-              await github.rest.issues.updateComment({
+            // Nothing below may throw: this step exists to post the new result,
+            // and losing that to a hiccup in the tidy-up of the old ones would
+            // be a poor trade. Both halves warn instead.
+            let previousBenchmarkComments = [];
+            try {
+              // The listing has to come from GraphQL: REST's comment payload
+              // omits isMinimized, so it cannot tell a comment this step has
+              // already collapsed from a live one, and each run would re-
+              // minimize the whole history.
+              const { repository } = await github.graphql(`
+                query($owner: String!, $repo: String!, $number: Int!) {
+                  repository(owner: $owner, name: $repo) {
+                    pullRequest(number: $number) {
+                      comments(last: 100) {
+                        nodes { id body isMinimized author { __typename } }
+                      }
+                    }
+                  }
+                }`, {
                 owner: context.repo.owner,
                 repo: context.repo.repo,
-                comment_id: comment.id,
-                body: outdatedPrefix + comment.body
+                number: context.issue.number
               });
+              previousBenchmarkComments =
+                repository.pullRequest.comments.nodes.filter(comment =>
+                  comment.author?.__typename === 'Bot' &&
+                  comment.body.includes(benchmarkIdentifier) &&
+                  !comment.isMinimized
+                );
+            } catch (error) {
+              core.warning(`Could not list benchmark comments: ${error.message}`);
+            }
+
+            // Collapse each as outdated. The likeliest failure is a token
+            // without the scope minimizeComment needs.
+            for (const comment of previousBenchmarkComments) {
+              try {
+                await github.graphql(`
+                  mutation($id: ID!) {
+                    minimizeComment(input: { subjectId: $id, classifier: OUTDATED }) {
+                      minimizedComment { isMinimized }
+                    }
+                  }`, { id: comment.id });
+              } catch (error) {
+                core.warning(
+                  `Could not collapse benchmark comment ${comment.id}: ${error.message}`
+                );
+              }
             }
 
+            // Create new comment with identifier
             const newCommentBody = benchmarkIdentifier + '\n' + process.env.BENCHMARK_MESSAGE;
 
             await github.rest.issues.createComment({