version: "1.0.0" name: bazel-pre-pr description: >- Runs pre-flight checks and deep code reviews on local commits of a Bazel feature branch before push or pull request creation. Use when asked to run a pre-PR check, review local commits against Bazel migration guidelines, or verify a feature branch before opening a pull request. Don't use for generic upstream merges (use dart-sdk-merge-upstream) or worktree bootstrap and teardown (use dart-sdk-bootstrap).

Bazel Pre-PR Pre-Flight Review (bazel-pre-pr)

This skill defines the pre-flight checks and local commit code review workflow to execute before a branch is pushed to remote or a pull request is created. It helps catch common Bazel migration bugs and style violations early.

When to Use This Skill

• Run this skill before staging a commit for upload or pushing a new feature

branch to GitHub.

• Trigger when the user requests "run pre-pr check", "review my local commits",

or "verify my feature branch before PR".

📋 Operational Workflow

Step 1: Feature Branch Validation (VCS Gate)

Before initiating any code analysis, you MUST verify that the local repository is in a valid state for code review:

1. Branch Check: Get the current git branch name.
2. Gate Criterion: The current branch MUST NOT be main (or the default

base branch). If it is main, stop immediately and print a hard-stop error: Error: Cannot run bazel-pre-pr on the 'main' branch. Please create a feature branch, commit your changes, and try again.

1. Commit Check: Ensure there is at least one local commit distinguishing

the current branch from the remote base (origin/main). Run: ``bash git log origin/main..HEAD --oneline ` If this returns empty, **stop immediately** and print: Error: No local commits found on this branch compared to origin/main.`

Step 2: Spin Up Code Review Subagent

If the branch checks pass, spin up a subagent of type self (inheriting all tools and rules) to run the code review in the background:

• Role: Bazel Code Reviewer
• Initial Task:

1. Retrieve the full diff of the local commits:

``bash git diff origin/main..HEAD ``

1. Read the active unified migration guidelines from the repository root:

{root-worktree}/docs/bazel-migration/GUIDELINES.md (where {root-worktree} is resolved dynamically for the current thread checkout).

1. Surgically audit all modifications in the diff against the guidelines

listed in that file. Pay special attention to "Part 2: Code-Level Patterns". When citing a violation, directly reference the specific "Rule" and adapt its "Prefer" block pattern to the specific code context in your suggested fix.

1. Conduct a general, highly skeptical engineering review of the diff: check

for logical robustness, verify assumptions, look for edge cases, resource cleanup misses, or race conditions, and identify opportunities to simplify the code.

1. Write a triage report artifact named bazel_pre_pr_review.md in the parent

conversation's artifacts directory.

1. The report MUST structure issues exactly like github-pr-triage:

• Header: # Pre-PR Review: <branch_name>
• Metadata: Commits analyzed, date, status.
• Issues Grouped by Category:
• For each issue:
• Context: File path and line range.
• Urgency: 🔥 Critical (causes compile/test failures or

sandboxing violations), ⚠️ Warning (style/performance degradation), 💡 Suggestion.

• The Flaw: Description of the guideline violated.
• The Recommended Fix: Correct vs. Incorrect code block comparison.

Step 3: Present Triage Report to User

Once the subagent finishes and writes the bazel_pre_pr_review.md artifact:

1. Load and present the triage report to the user.
2. The report file MUST be created as a user-facing artifact with

RequestFeedback: true in the metadata to render the Proceed button.

1. If no critical issues are found, notify the user that the branch is ready for

push. If issues are found, prompt the user to approve the planned refactorings or fixes.