oh-join

name	oh-join
description	Resolve multi-dependency fan-in by merging dependency PRs into a common base and updating issue dependencies

oh-join

Use this skill when an issue has 2+ open dependencies and scheduler cannot auto-stack because there is no single base branch.

Invocation

/oh-join <issue-number>

• <issue-number>: target GitHub issue (for example 1178 or #1178)

Goal

For target issue #X:

1. Read Depends on: dependencies
2. Find linked open PRs for those dependency issues
3. Verify dependency PRs are ready to merge
4. Merge them into one common base branch in deterministic order
5. Update target issue dependencies to reflect merged deps
6. Signal completion with outcome details

Flow

1. Load issue and dependencies

   gh issue view <issue-number> --json number,title,body,state,url
   

   • Parse all dependency numbers from Depends on: lines.
   • If fewer than 2 dependencies: stop with blocked (not a join case).

2. Discover open PRs for dependency issues

   gh pr list --state open --json number,title,headRefName,baseRefName,body,url
   

   • Map dependency issue number -> linked PR by either:
     • branch pattern issue/<N> or issue-<N>
     • PR body containing Closes #N / Fixes #N / Resolves #N
   • If any dependency has no open PR: stop with blocked and list missing deps.

3. Determine common base branch

   • Collect baseRefName across dependency PRs.
   • If all same: that is the common base branch.
   • If different:
     • Attempt to find shared upstream branch by checking whether all base branches descend from a common candidate.
     • If no safe common base is found, stop with blocked and report conflicting bases.

4. Readiness checks for each dependency PR For each dep PR:

   gh pr checks <pr-number> --fail-on-error
   gh pr view <pr-number> --json reviewDecision,isDraft,mergeable
   

   • Must not be draft
   • Must be mergeable
   • CI checks must pass
   • Review decision must not be CHANGES_REQUESTED
   • The complete repository /ship pipeline must be evidenced on the final commit
   • Every PR must have an explicit APPROVE from a fresh, separate repo-local /review sub-agent for the exact final commit
   • Any diff change after that approval invalidates it and requires a new fresh reviewer
   • CodeRabbit is optional supplemental feedback: never trigger or wait for it, but verify any actionable comments already present were addressed If any fail: stop with blocked and report specific PR reasons.

5. Merge dependency PRs in deterministic order and close their issues

   • Sort by dependency issue number ascending.

   • If either final-diff gate above is missing, delegate that PR to canonical /ship and wait; never call gh pr merge directly.

   • For each dependency pair (issue #D, PR #P) in order:

     gh pr merge <pr-number> --squash
     gh issue close <dep-issue-number> --comment "Closed via oh-join after merging PR #<pr-number> into <base-branch>."
     

   • Why explicit close: PRs merged into non-default branches do NOT auto-close issues, even with Closes #N.

   • On failure:

     • Stop immediately
     • Report merged PRs/issues vs failed PR
     • signal_completion(status: "error", error: "...")

6. Update target issue dependencies

   • Re-read target issue body.

   • Rewrite Depends on: to one explicit scheduler-readable base dependency.

   • Required: common base branch MUST be issue/<B> or issue-<B>; then set: **Depends on:** #<B>

   • If common base is not an issue branch (for example main/master), stop with blocked and do NOT rewrite dependencies to none.

   • Do NOT leave merged dependency references in strikethrough (~~#N~~) form — remove them completely.

   • Append/update a machine section:

     <!-- oh-join -->
     Joined deps: #A (PR #PA), #B (PR #PB)
     Base branch: <branch>
     Updated: <ISO timestamp>
     

   • Write back:

     gh issue edit <issue-number> --body-file <temp-file>
     

7. Completion signaling

   • Success:

     signal_completion(status: "success", message: "Merged dep PRs #... into <base>; updated issue #<issue-number> dependencies")
     

   • Blocked:

     signal_completion(status: "blocked", blocker: "<reason>")
     

   • Error:

     signal_completion(status: "error", error: "<reason>")
     

Safety Rules

• Never merge PRs not linked to target dependencies.
• Never merge if CI is red/pending.
• Never continue after first merge failure.
• Never delete dependency context; only remove deps that are now merged.
• Always include exact issue/PR numbers in reports.
• Never rely on PR auto-close when merging into non-default branches; explicitly close dependency issues.
• For stacked continuation, leave exactly one explicit Depends on: #<base-issue> when base is an issue branch.

Exit Conditions

• Success: all dependency PRs merged and issue dependencies updated
• Blocked: missing dep PR, ambiguous base, non-issue base branch, or failing readiness checks
• Error: merge/update operation failed unexpectedly

Completion Signaling (MANDATORY)

You MUST call signal_completion as your final action.

If the tool is unavailable, end with one line:

• COMPLETION: status=success message=<...>
• COMPLETION: status=blocked blocker=<...>
• COMPLETION: status=error error=<...>