check-milestones

name	check-milestones
description	Check and fix milestones on PRs and their associated issues. Sets PR milestones based on the branch they merged into, and issue milestones based on the smallest version with a merged fix. Triggers on: check milestones, fix milestones, /check-milestones.
argument-hint	[github-username] [all|PR1,PR2,PR3]
allowed-tools	Bash, Read, Grep, Glob

Check Milestones

Check and fix milestones on a contributor's merged PRs and their associated GitHub issues.

Inputs

• Arguments: $ARGUMENTS -- space-separated values:
  • First argument: GitHub username (the author whose merged PRs to check)
  • Second argument (optional): PR filter -- either:
    • all -- evaluate all closed/merged PRs from this author in the past 30 days.
    • A comma-separated list of PR numbers with no spaces (e.g., 100,105,110) -- only evaluate these specific PRs.
    • If omitted, defaults to the recent 50 closed PRs.

Parse the arguments by splitting $ARGUMENTS on whitespace. Examples:

• /check-milestones alice -> username=alice, filter=recent 50
• /check-milestones alice all -> username=alice, filter=all PRs (past 30 days)
• /check-milestones alice 100,105,110 -> username=alice, filter=only those PRs

---

Step 1: Gather Information

Auto-detect the repository:

REPO=$(gh repo view --json nameWithOwner --jq '.nameWithOwner')

Run these in parallel:

1. Fetch PRs (method depends on the second argument):

   • Default (no second arg): Use gh pr list --repo $REPO --author <username> --state closed --limit 50 --json number,title,mergedAt,mergeCommit,labels,body,url,baseRefName,milestone --jq 'sort_by(.mergedAt)'
   • all: Use gh pr list --repo $REPO --author <username> --state closed --limit 200 --search "closed:>YYYY-MM-DD" --json number,title,mergedAt,mergeCommit,labels,body,url,baseRefName,milestone --jq 'sort_by(.mergedAt)' where YYYY-MM-DD is 30 days ago from today.
   • Comma-separated PR list: For each PR number, use gh pr view <number> --repo $REPO --json number,title,mergedAt,mergeCommit,labels,body,url,baseRefName,milestone. Collect results sorted by mergedAt.

   Skip any PR where mergedAt is null (not merged).

2. Auto-detect milestone naming convention: Fetch existing milestones from the repo to understand the naming pattern:

   gh api "repos/$REPO/milestones" --paginate --jq '.[].title' | sort -V
   

   From the existing milestones, detect the naming convention. Common patterns:

   • v1.2.3 (semver)
   • 1.89.x - Nightly (channel-based)
   • Sprint 42 (sprint-based)
   • 2024-Q1 (quarter-based)
   • Release 5.0 (release-based)

3. Detect the default branch and release branches:

   DEFAULT_BRANCH=$(gh repo view --json defaultBranchRef --jq '.defaultBranchRef.name')
   # List branches that look like release branches
   gh api "repos/$REPO/branches" --paginate --jq '.[].name' | grep -E '(release|v?[0-9]+\.[0-9]+)' | sort -V
   

---

Step 2: Determine Correct PR Milestones

For each merged PR, determine the correct milestone based on its baseRefName (the branch it was merged into):

• If baseRefName is the default branch (main or master) -> the milestone corresponding to the development/nightly channel
• If baseRefName matches a release branch -> the milestone corresponding to that release version

To map branches to milestones, use the auto-detected milestone naming convention from Step 1. Match the version number in the branch name to the closest milestone.

Compare the PR's current milestone (from the milestone field) against the correct one. If they differ (or the milestone is not set), add the PR to the list of PRs that need updating.

---

Step 3: Determine Correct Issue Milestones

For each merged PR, extract the associated issue number(s) from the PR body. Look for patterns like:

• Resolves #XXXXX or Resolves OWNER/REPO#XXXXX
• Fixes #XXXXX or Fixes OWNER/REPO#XXXXX
• Closes #XXXXX or Closes OWNER/REPO#XXXXX
• Fixes https://github.com/OWNER/REPO/issues/XXXXX
• Resolves https://github.com/OWNER/REPO/issues/XXXXX

For each associated issue:

1. Find all PRs that reference this issue -- check if the issue has cherry-pick/uplift PRs by searching for other merged PRs that reference the same issue across different branches:

   gh api search/issues --method GET \
     -f q="repo:$REPO is:pr is:merged $ISSUE_NUMBER" \
     --jq '.items[] | {number, title, html_url}'
   

2. Determine which branches this fix has been merged into (considering cherry-picks/uplifts):

   • The original PR's base branch
   • Any cherry-pick/uplift PRs merged into release branches

3. The correct issue milestone is the smallest version where the fix is merged. Use the version ordering from the auto-detected milestones to determine which is smallest.

4. Check the issue's current milestone and compare:

   gh issue view <ISSUE_NUMBER> --repo $REPO --json milestone --jq '.milestone.title'
   

---

Step 4: Apply Milestone Updates

Update PR Milestones

For each PR that needs a milestone update:

gh pr edit <PR_NUMBER> --repo $REPO --milestone "<milestone-name>"

Update Issue Milestones

For each issue that needs a milestone update:

gh issue edit <ISSUE_NUMBER> --repo $REPO --milestone "<milestone-name>"

Important: Only update an issue's milestone to a smaller version number than what is currently set. For example:

• Milestone is unset -> set it to the computed milestone
• Milestone is a development/nightly milestone but fix was cherry-picked to a release branch -> update to the release milestone
• Do NOT update if the current milestone already has a smaller version number than the computed one

---

Step 5: Summary

Output a clear summary of all actions taken:

PR Milestones Updated:

PR	Title	Base Branch	Old Milestone	New Milestone
#XXXXX	PR title	main	(none)	v2.1.0

Issue Milestones Updated:

Issue	Old Milestone	New Milestone	Reason
#XXXXX	(none)	v2.0.1	Merged cherry-pick to release (#YY)

Already Correct:

List PRs and issues that already had the correct milestone (brief count or list).

Skipped:

List any PRs or issues that were skipped with the reason (e.g., "no associated issue", "could not determine branch", "unmerged cherry-pick").