Pr Review Canvas

🗺️ Skill: pr-review-canvas

Purpose

Turn an unstructured diff into a structured review map: what changed, why it matters, where to look first, and what to be careful about. Helps reviewers focus attention rather than read everything.

Note: Cursor's own official cursor-team-kit plugin ships a skill with this same name. This version outputs a plain-text/markdown reviewer map printed to chat (optionally saved as PR_CANVAS.md) rather than an interactive HTML walkthrough — no rendering step, works the same in any client that can display markdown.

Trigger phrases

• "review canvas"
• "map this PR"
• "pr-review-canvas"
• "give me a PR overview"
• "structure this PR for review"

Steps

1. Fetch the diff

# If PR number is known:
gh pr diff <number>

# If on the branch:
git diff main...HEAD --stat
git diff main...HEAD

Also fetch the PR description:

gh pr view <number>

2. Categorize every changed file

Assign each file to one category:

3. Build the reviewer map

## PR Canvas: <PR title>

### Summary
<2-3 sentences: what this PR does and why>

### Change map
| File / Area | Category | Lines ±  | Risk | Reviewer note |
|-------------|----------|----------|------|---------------|
| src/foo.ts  | Feature  | +120/-30 | Med  | Core logic change — review carefully |
| tests/foo.test.ts | Test | +80 | Low | Covers happy path + 2 edge cases |
| config/env.example | Config | +3 | Low | New env var — check deployment runbook |

### Risk sections (read these first)
1. <file>:<line-range> — <reason it's risky>
2. ...

### What's NOT in this PR (but might be expected)
- <missing tests for X>
- <no migration for schema change>
- ...

### Suggested review order
1. <file or area to read first>
2. ...

4. Flag concerns

Automatically flag:

• Files changed without accompanying tests (for non-trivial logic).
• Config changes with no documentation update.
• Large single files (>300 lines changed) — suggest splitting if not already merged.
• Direct changes to main/master branch protection files.
• Secrets-adjacent files (.env, credential configs).

5. Output

Print the reviewer map to chat. If the user asks, also write it as PR_CANVAS.md in the repo root (gitignored by default).

Output

Structured reviewer map with change categorization, risk flags, and suggested review order.

Gotchas

• gh pr diff <number> and gh pr view <number> need gh authenticated against the right repo — if gh auth status fails, fall back to local git diff against the base branch and say the PR metadata (description, comments) is unavailable rather than silently omitting it.
• Line-count-based risk ("Med"/"High") is a heuristic, not a real risk signal — a 5-line change to auth middleware is higher risk than a 200-line change to a test fixture. Weigh what the file does, not just its diff size.
• Renamed/moved files can appear as large deletes+adds in the stat — check for a rename before categorizing them as a big risky change.