stable-release-notes

name	stable-release-notes
description	Prepare GitHub release notes for a beta or stable web-components release. Adds a "Changes Since {previous}" block (breaking / behavior altering changes and new features only, since the previous minor) on top of the bot-generated "Changes Since" block in the draft.
argument-hint	<current-version>
disable-model-invocation	true
allowed-tools	Read, Write, Bash(node:*), Bash(gh:*), Bash(git:*)

Prepare the GitHub release notes draft for version $0 (e.g. 25.2.0-beta1, 25.2.0, v25.2.0-rc1).

The goal is to insert a new "Changes Since {previous}" block — listing only breaking changes and new features accumulated since the previous minor — directly after the API documentation link, while preserving the existing bot-generated "Changes Since" block below it.

Steps

1. Normalize {current}:

   • Treat $0 as the version tag. Prepend v if missing (e.g. 25.2.0-beta1 → v25.2.0-beta1).
   • Extract <major>.<minor> (e.g. v25.2.0-beta1 → 25.2) for the alpha1 lookup in step 2.
   • Remember <major> (e.g. 25) — used in step 5.

2. Resolve {previous} from alpha1:

   • Run gh release view v<major>.<minor>.0-alpha1 --repo vaadin/web-components.
   • In the body, find the line that starts with ### Changes Since [<tag>](...).
   • Take the <major>.<minor> portion of that <tag> and form {previous} = v<major>.<minor>.0 — the stable of the previous minor/major (e.g. alpha1 referencing v25.1.0-beta2 → {previous} = v25.1.0).

3. Make sure both tags are available locally:

   • Fetch each tag explicitly so a conflict on an unrelated tag can't silently skip them: git fetch origin "refs/tags/{previous}:refs/tags/{previous}" "refs/tags/{current}:refs/tags/{current}".
   • Verify git rev-parse {previous} and git rev-parse {current} both resolve.

4. Generate release notes:

   • Run node ./scripts/generateReleaseNotes.js --from {previous} --to {current} from the repo root.
   • Capture the full stdout — this is the raw notes for the {previous}..{current} range.

5. Filter the generated output:

   • Keep the ### Changes Since [{previous}](...) heading line.
   • Keep only the #### sections whose heading text (ignoring the emoji) ends with Breaking Changes or New Features. Drop every other #### section.
   • Drop the leading version line and the [API Documentation →] line — those already exist in the draft.
   • If {current} and {previous} share the same major (e.g. 25.2 vs 25.1 — both 25), rename the kept Breaking Changes heading to Behavior Altering Changes, leaving the emoji intact. Keep Breaking Changes when the major differs (e.g. 26.0 vs 25.2).

6. Read the existing draft:

   • Run gh release view {current} --repo vaadin/web-components --json body,isDraft,url.
   • If the release is not a draft, stop and ask before continuing.
   • Note the existing body — it contains an [API Documentation →] line followed (after a blank line) by an ### Changes Since [<alpha-or-rc-tag>]... block. That existing block must remain intact below the new one.

7. Build the new body:

   • Locate the [API Documentation →] line in the existing body.
   • Insert the filtered block from step 5 right after that line, separated by one blank line above and one blank line below.
   • Keep the existing ### Changes Since ... block (and everything beneath it) exactly as it was, immediately after the inserted block.
   • Result layout:

     [API Documentation →](...)
     
     ### Changes Since [{previous}](...)
     
     #### :boom:　Behavior Altering Changes   (or "Breaking Changes" when major bumps)
     - ...
     
     #### :rocket:　New Features
     - ...
     
     ### Changes Since [<existing-tag>](...)
     
     #### ... (existing sections untouched)
     

8. Update the draft:

   • Write the new body to a temporary file (e.g. /tmp/release-notes-{current}.md).
   • Run gh release edit {current} --repo vaadin/web-components --notes-file <tmp-file>.

9. Report:

   • Print the draft preview URL from gh release view {current} --repo vaadin/web-components --json url -q .url so the user can review before publishing.
   • Do not publish the release.

Notes

• All GitHub operations go through the gh CLI.
• Run all commands from the repository root so ./scripts/generateReleaseNotes.js resolves correctly.
• The previous tag is derived from alpha1's "Changes Since" — that anchors the new block to the previous minor's last release, regardless of how many alphas this minor has had.
• Only Breaking / Behavior Altering Changes and New Features go into the new block; the unfiltered detail still lives in the original block below.
• Use "Behavior Altering Changes" when {current} and {previous} share the same major; use "Breaking Changes" when the major bumps.