fix(pr-review): checkout agent repo explicitly for consumer callers (#536)

[don-petry]

Caught by ring-1 (markets). The reusable's 'Checkout agent repo' step had ref: agent_ref but no repository:, so it cloned the caller's repo — fine for self-host (caller is .github-private), but for a consumer (markets) it tried markets@pr-review/stable (no such ref) → checkout failure.

Fix: repository: petry-projects/.github-private (public → default token reads it) + ref: agent_ref || 'main'. Scripts always come from the agent repo; review-one-pr.sh uses the gh API, no target checkout needed. No self-host change.

After merge: cut pr-review/v1.5.0, move stable, re-validate markets#261. Part of #536 · #497 · epic #495.

Summary by CodeRabbit

• Chores
  • Updated internal workflow configuration to improve default branch handling for agent scripts during pull request reviews.

[gemini-code-assist]

Note

Gemini is unable to generate a review for this pull request due to the file types involved not being currently supported.

[coderabbitai]

📝 Walkthrough

Walkthrough

The workflow's "Checkout agent repo" step is updated to explicitly default the .github-private repository checkout ref to the main branch when inputs.agent_ref is not provided, replacing a bare input reference with a fallback expression and adjusting the inline comments to document this behavior.

Changes

Agent checkout default branch

Layer / File(s)	Summary
Agent ref defaulting to main .github/workflows/pr-review.yml	The actions/checkout ref for .github-private is changed from ${{ inputs.agent_ref }} to ${{ inputs.agent_ref || 'main' }} to ensure the workflow defaults to the main branch when agent_ref is empty, with expanded inline comments documenting this fallback behavior.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related issues

• petry-projects/.github-private#506: Both changes involve the same actions/checkout step and handling of inputs.agent_ref, with this PR applying an explicit fallback to main when the input is empty.

Possibly related PRs

• petry-projects/.github-private#513: This PR directly extends the agent_ref input wiring introduced by PR #513 by adding a fallback default when the input is not provided.
• petry-projects/.github-private#74: Both PRs modify the same .github/workflows/pr-review.yml "Checkout agent repo" step, this one changing the ref default behavior and PR #74 pinning the actions/checkout action version.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically summarizes the main change: fixing the agent repo checkout to be explicit for consumer callers. It directly relates to the changeset which updates the checkout step behavior.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/checkout-agent-repo-explicit

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[don-petry]

Dev-Lead — fix-bot-comment (no-changes)

Agent reasoning

Issues addressed: 0
Files changed: none
Skipped (informational): 1 — Gemini reported it cannot review this PR
  due to unsupported file types (YAML/shell workflows); no actionable
  findings were raised and no open review threads exist from this bot.
```

[Copilot]

Pull request overview

This PR fixes a failure mode when .github/workflows/pr-review.yml is invoked as a reusable workflow from consumer repositories: the workflow now explicitly checks out the agent scripts repository (petry-projects/.github-private) instead of implicitly checking out the caller repo (which can’t satisfy refs like pr-review/stable).

Changes:

• Update the “Checkout agent repo” step to set repository: petry-projects/.github-private.
• Adjust the checkout ref selection logic for agent_ref (with a default fallback) and expand inline documentation explaining the consumer-repo failure scenario.

[coderabbitai]

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

.github/workflows/pr-review.yml (1)

6-16: ⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Update the input description to reflect the new default behavior.

The comment at lines 11-12 states that empty agent_ref "preserves the historical behaviour exactly: actions/checkout treats an empty ref as 'default'", but the implementation at line 184 now explicitly defaults to 'main' when agent_ref is empty (${{ inputs.agent_ref || 'main' }}). This is a behavior change from letting actions/checkout choose its default branch.

📝 Suggested fix to align the input description with the implementation

       # The .github-private ref to check out for the agent's own scripts
       # (engine.sh, review-one-pr.sh, …). A trigger-stub caller passes its
       # pinned channel (e.g. pr-review/stable) so the SCRIPTS run at the
       # pinned version, not the caller's branch — closing the reusable
-      # self-ref gap (`#506`). Empty (the default) preserves the historical
-      # behaviour exactly: actions/checkout treats an empty ref as "default".
+      # self-ref gap (`#506`). Empty (the default) uses 'main' to ensure
+      # a consistent baseline when no specific ref is pinned (`#506/`#536).
       description: "Ref of petry-projects/.github-private to check out for agent scripts"

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In @.github/workflows/pr-review.yml around lines 6 - 16, The input description
for agent_ref is out of sync with the implementation: the workflow uses the
expression `${{ inputs.agent_ref || 'main' }}` so an empty agent_ref no longer
defers to actions/checkout's default but explicitly falls back to 'main'; update
the description for the agent_ref input to state that an empty value will
default to 'main' (reference the agent_ref input and the `${{ inputs.agent_ref
|| 'main' }}` fallback) so docs match the actual behavior.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Outside diff comments:
In @.github/workflows/pr-review.yml:
- Around line 6-16: The input description for agent_ref is out of sync with the
implementation: the workflow uses the expression `${{ inputs.agent_ref || 'main'
}}` so an empty agent_ref no longer defers to actions/checkout's default but
explicitly falls back to 'main'; update the description for the agent_ref input
to state that an empty value will default to 'main' (reference the agent_ref
input and the `${{ inputs.agent_ref || 'main' }}` fallback) so docs match the
actual behavior.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 5c379bad-55b3-4ea8-b95d-d6ea1aa58cf6

📥 Commits

Reviewing files that changed from the base of the PR and between 38448af and 7256075.

📒 Files selected for processing (1)

• .github/workflows/pr-review.yml

[don-petry]

Dev-Lead — fix-reviews (applied)

Changes committed and pushed.