Verify Diff — Prove It Works

Compare the current branch against the base branch (main, or develop/whatever your project integrates into) to verify no regressions were introduced.

Substitute your base branch and your project's own quality-gate commands throughout. The commands below use generic placeholders — read the real ones from package.json scripts / your build config.

Steps

1. Identify Changed Files

git diff main...HEAD --name-only

2. Run Tests on Current Branch

<test command> 2>&1 | tee /tmp/verify-diff-current.txt

3. Run Type Check

<typecheck command> 2>&1 | tee /tmp/verify-diff-types.txt

4. Run Lint

<lint command> 2>&1 | tee /tmp/verify-diff-lint.txt

5. Compare Against the Base Branch

git stash
git checkout main
<test command> 2>&1 | tee /tmp/verify-diff-base.txt
git checkout -
git stash pop

6. Diff Results

Compare test output between branches. Report:

• New test failures (tests that passed on the base branch but fail on the current branch)
• New lint errors introduced
• New type errors introduced
• Tests that were removed (may indicate coverage regression)

Output Format

## Verify Diff Report

**Branch:** feature/my-feature vs main
**Changed files:** 12

### Test Comparison
- base:    142 passed, 0 failed
- current: 143 passed, 0 failed (+1 new test)
- No regressions ✓

### Type Check
- No new type errors ✓

### Lint
- No new lint errors ✓

### Verdict: PASS — Safe to push

If regressions are found:

### Verdict: FAIL — Regressions detected
- `someModule.test.ts > handles empty input` — FAILED (was passing on the base branch)

Pre-Push Hook

If the skill folder includes a companion pre-push-check.sh, it runs a lightweight version (tests + types only) to gate pushes. Wire your project's actual commands into it before relying on it.