Duplicate Storybook build status comments on PRs

[benceruleanlu]

Human Preface/Disclaimer

The only issue I actually saw/can confirm was the double storybook comments in #5274, but I do not know the cause of this issue.

Everything below this point is completely triaged and generated by Opus 4.1 Claude Code.

Problem Description

When multiple commits are pushed to a PR in quick succession, duplicate "Storybook Build Status" comments are created instead of updating a single comment. This was observed in PR #5274 where two identical Storybook status comments were posted.

Root Cause Analysis

Each commit triggers its own Chromatic workflow run, and each Chromatic run triggers a separate pr-storybook-comment workflow via the workflow_run event. When these workflows run concurrently or in rapid succession, a race condition occurs:

1. Both workflows search for existing comments with <!-- STORYBOOK_BUILD_STATUS --> marker
2. Neither finds the other's comment (as they're created nearly simultaneously)
3. Both create new comments instead of updating an existing one

Timeline Example (from PR #5274)

• Commit 1 (33035ee at 00:22:04Z) → Chromatic run no. 423 → Comment created at 12:22:57
• Commit 2 (91ad2a0 at 00:25:50Z) → Chromatic run no. 424 → Comment created at 12:26:17

Proposed Solutions

Option 1: Add Concurrency Control (Recommended)

Add concurrency settings to pr-storybook-comment.yaml to ensure only one instance runs per PR:

concurrency:
  group: storybook-comment-${{ github.event.workflow_run.pull_requests[0].number }}
  cancel-in-progress: true

Option 2: Use More Specific Comment Markers

Include additional identifiers in the comment marker to prevent collisions:

body-includes: '<!-- STORYBOOK_BUILD_STATUS_PR_${{ steps.pr.outputs.result }} -->'

Option 3: Add Delay and Retry Logic

Implement a small delay and retry mechanism to check for recently created comments before creating a new one.

Impact

• Creates confusion with multiple status comments on PRs
• Clutters PR discussion threads
• May cause notification spam for PR participants

Related Information

• Issue introduced after PR [feat] Implement pull_request_target deployment for forked PRs - solves secret access issue #5209 which implemented the workflow_run architecture for CI comment/deploy separation
• Affects both pr-storybook-comment.yaml and potentially pr-playwright-comment.yaml workflows

┆Issue is synchronized with this Notion page by Unito

[christian-byrne]

We fixed this?