Fix preview links for long branch names#4469
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When a branch name produces a subdomain exceeding 63 characters (the DNS label limit), Vercel truncates it with a hash suffix. Our workflow constructed the URL independently and got it wrong in those cases. Now the workflow checks the subdomain length first. Short branch names use the constructed URL directly with no delay. Long branch names poll for the Vercel bot comment and extract the actual preview URL from its base64 payload, falling back to the constructed URL after 3 minutes. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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📖 Docs PR preview linksThis PR does not change any pages in /docs. If you make updates, links to the modified pages will appear here. |
| uses: actions/github-script@v7 | ||
| with: | ||
| github-token: ${{ secrets.GITHUB_TOKEN }} | ||
| script: | |
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Just a nit, but could this script be put in a file like preview-base-url.js? It's usually easier to write and maintain these scripts when they're not embedded in the workflow.
Then the package.json > "scripts" section could be updated with something like preview-base-url and then called here like: yarn run preview-base-url.
flippedcoder
approved these changes
Apr 22, 2026
Moves the inline script from the workflow into a standalone file for easier maintenance. The workflow now requires it and calls resolvePreviewUrl with the actions/github-script context. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
vercel[bot]comment (up to 3 minutes) and extract the actual preview URL from its base64 payload, falling back to the constructed URL if the comment doesn't appear.Test plan
fix/this-is-a-very-long-branch-name-that-will-exceed-the-dns-label-limit) and confirm the workflow extracts the correct URL from the Vercel comment🤖 Generated with Claude Code
┆Attachments: EDU-6246 Fix preview links for long branch names