ci: refresh PR mergeability before queue decisions

[seonghobae]

Summary

• Refresh each open PR with REST mergeable_state before scheduler decisions.
• Prefer REST dirty, behind, and unknown over potentially stale GraphQL mergeStateStatus.
• Prevent stale CLEAN readings from enabling auto-merge on conflicted PRs, and route approved behind PRs to update_branch with workflow GITHUB_TOKEN / github-actions[bot] guidance.

Why

A live downstream scheduler run showed stale GraphQL merge state: PR #450 was actually dirty but auto-merge stayed enabled, while approved behind PRs like #451 were not routed to update-branch. The scheduler now reads GitHub REST mergeability before acting.

Verification

• python3 -m coverage run -m pytest
• python3 -m coverage report --fail-under=100
• python3 scripts/ci/pr_review_merge_scheduler.py --self-test
• python3 -m py_compile scripts/ci/pr_review_merge_scheduler.py
• python3 -m interrogate -c pyproject.toml .
• git diff --check

[Copilot]

Pull request overview

This PR updates the PR review/merge scheduler to refresh each open PR’s mergeability using GitHub’s REST mergeable_state before making queue decisions, reducing reliance on potentially stale GraphQL mergeStateStatus/mergeStateStatus-adjacent signals.

Changes:

• Add REST mergeability fetching/normalization helpers and enrich fetched PR payloads with restMergeableState.
• Use an effective_merge_state() to prefer REST DIRTY, BEHIND, and UNKNOWN when deciding whether to disable auto-merge, wait, or request update_branch.
• Extend unit tests to cover REST mergeability helper behavior and decision routing when REST and GraphQL disagree.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
scripts/ci/pr_review_merge_scheduler.py	Adds REST mergeability enrichment and updates decision logic to prefer REST evidence (incl. explicit handling for UNKNOWN).
tests/test_pr_review_merge_scheduler.py	Updates PR fixtures and adds/extends tests to validate REST mergeability helpers and new decision behaviors.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[opencode-agent]

OpenCode Review Overview

• Head SHA: 5c6f069444b0a42b0f4c474feb9b97019a53ecf0
• Workflow run: 28191640929
• Workflow attempt: 1
• Gate result: APPROVE (approval step)

Pull request overview

OpenCode reviewed the current-head bounded evidence and found no blocking issues.

Findings

No blocking findings.

Summary

Changes enhance merge safety by adding REST mergeable_state checks. Verification posture: Linter/static: PASS (no new lint issues), TDD/regression: PASS (tests cover new states), Coverage: 100%, Docstring coverage: 100%, DAG: [mermaid graph], PoC/execution: Verified scheduler behavior in self-test, DDD/domain: Consistent with GitHub merge workflows, CDD/context: Matches repository conventions, Similar issues: None found, Claim/concept check: REST mergeable_state docs verified, Standards search: Matches GitHub API conventions, Compatibility/convention: Backward-compatible, Breaking-change/backcompat: None, Performance: No degradation, Developer experience: Improves scheduler transparency, User experience: Reduces stale merge states, Security/privacy: No new risks

Verification posture: CodeGraph evidence was initialized and bounded current-head evidence reviewed for changed-file evidence including scripts/ci/pr_review_merge_scheduler.py, tests/test_pr_review_merge_scheduler.py.
Linter/static: workflow/static review evidence is bounded by the current-head GitHub Checks gate and changed-file evidence.
TDD/regression: coverage execution evidence and focused changed hunks were reviewed from bounded-review-evidence.md.
Coverage: coverage execution evidence proves 100% test coverage.
Docstring coverage: coverage execution evidence proves 100% docstring coverage.
DAG: Change Flow DAG maps scripts/ci/pr_review_merge_scheduler.py through bounded evidence, review risk, and required checks.
PoC/execution: coverage-evidence job executed on the current head and reported PASS.
DDD/domain: workflow and repository-governance invariants were reviewed against changed files in bounded evidence.
CDD/context: CodeGraph evidence, changed-file history, and focused hunks were reviewed from bounded-review-evidence.md.
Similar issues: changed-file history evidence was reviewed for comparable local precedents.
Claim/concept check: bounded evidence, repository source, and current-head workflow evidence were used for claims.
Standards search: standards and external-source checks are delegated to configured OpenCode web_search/Context7/DeepWiki sources when applicable; no evidence-backed standards blocker is present in bounded evidence.
Compatibility/convention: changed workflow/script conventions and compatibility surfaces were checked in bounded evidence.
Breaking-change/backcompat: deployment evidence and changed-file history were checked for backward-compatibility risk.
Performance: changed surfaces were checked for performance risk in bounded evidence.
Developer experience: changed automation, review, and maintenance surfaces were checked for helpful or obstructive DX impact in bounded evidence.
User experience: changed files did not identify a user-facing UI surface; bounded evidence was reviewed for UX impact.
Security/privacy: workflow-token, review-gate, and repository-automation security/privacy boundaries were checked in bounded evidence.

• Result: APPROVE
• Reason: No blocking issues found
• Head SHA: 5c6f069444b0a42b0f4c474feb9b97019a53ecf0
• Workflow run: 28191640929
• Workflow attempt: 1

Change Flow DAG

flowchart LR
PR["PR changed files"] --> Evidence["OpenCode bounded evidence"]
Evidence --> S1["CI script: pr_review_merge_scheduler.py"]
S1 --> I1["review and security gate shell path"]
I1 --> R1["Review risk: CI script: pr_review_merge_scheduler.py"]
R1 --> V1["bash -n plus Strix self-test"]
Evidence --> S2["Test: test_pr_review_merge_scheduler.py"]
S2 --> I2["regression suite"]
I2 --> R2["Review risk: Test: test_pr_review_merge_scheduler.py"]
R2 --> V2["targeted test run"]

Loading

[opencode-agent]

Pull request overview

OpenCode reviewed the current-head bounded evidence and found no blocking issues.

Findings

No blocking findings.

Summary

Changes enhance merge safety by adding REST mergeable_state checks. Verification posture: Linter/static: PASS (no new lint issues), TDD/regression: PASS (tests cover new states), Coverage: 100%, Docstring coverage: 100%, DAG: [mermaid graph], PoC/execution: Verified scheduler behavior in self-test, DDD/domain: Consistent with GitHub merge workflows, CDD/context: Matches repository conventions, Similar issues: None found, Claim/concept check: REST mergeable_state docs verified, Standards search: Matches GitHub API conventions, Compatibility/convention: Backward-compatible, Breaking-change/backcompat: None, Performance: No degradation, Developer experience: Improves scheduler transparency, User experience: Reduces stale merge states, Security/privacy: No new risks

Verification posture: CodeGraph evidence was initialized and bounded current-head evidence reviewed for changed-file evidence including scripts/ci/pr_review_merge_scheduler.py, tests/test_pr_review_merge_scheduler.py.
Linter/static: workflow/static review evidence is bounded by the current-head GitHub Checks gate and changed-file evidence.
TDD/regression: coverage execution evidence and focused changed hunks were reviewed from bounded-review-evidence.md.
Coverage: coverage execution evidence proves 100% test coverage.
Docstring coverage: coverage execution evidence proves 100% docstring coverage.
DAG: Change Flow DAG maps scripts/ci/pr_review_merge_scheduler.py through bounded evidence, review risk, and required checks.
PoC/execution: coverage-evidence job executed on the current head and reported PASS.
DDD/domain: workflow and repository-governance invariants were reviewed against changed files in bounded evidence.
CDD/context: CodeGraph evidence, changed-file history, and focused hunks were reviewed from bounded-review-evidence.md.
Similar issues: changed-file history evidence was reviewed for comparable local precedents.
Claim/concept check: bounded evidence, repository source, and current-head workflow evidence were used for claims.
Standards search: standards and external-source checks are delegated to configured OpenCode web_search/Context7/DeepWiki sources when applicable; no evidence-backed standards blocker is present in bounded evidence.
Compatibility/convention: changed workflow/script conventions and compatibility surfaces were checked in bounded evidence.
Breaking-change/backcompat: deployment evidence and changed-file history were checked for backward-compatibility risk.
Performance: changed surfaces were checked for performance risk in bounded evidence.
Developer experience: changed automation, review, and maintenance surfaces were checked for helpful or obstructive DX impact in bounded evidence.
User experience: changed files did not identify a user-facing UI surface; bounded evidence was reviewed for UX impact.
Security/privacy: workflow-token, review-gate, and repository-automation security/privacy boundaries were checked in bounded evidence.

• Result: APPROVE
• Reason: No blocking issues found
• Head SHA: 5c6f069444b0a42b0f4c474feb9b97019a53ecf0
• Workflow run: 28191640929
• Workflow attempt: 1