android/.claude/skills/reviewing-changes/checklists/bug-fix.md

Bug Fix Review Checklist

Multi-Pass Strategy

First Pass: Understand the Bug

1. Understand root cause:

• What was the broken behavior?
• What caused it?
• How does this fix address the root cause?

2. Assess scope:

• How many files changed?
• Is this a targeted fix or broader refactoring?
• Does this affect multiple features?

3. Check for side effects:

• Could this break other features?
• Are there edge cases not considered?

Second Pass: Verify the Fix

4. Code changes:

• Does the fix make sense?
• Is it the simplest solution?
• Any unnecessary changes included?

5. Testing:

• Is there a regression test?
• Does test verify the bug is fixed?
• Are edge cases covered?

6. Related code:

• Same pattern in other places that might have same bug?
• Should other similar code be fixed too?

What to CHECK

✅ Root Cause Analysis

• Does the fix address the root cause or just symptoms?
• Is the explanation in PR/commit clear?

✅ Regression Testing

• Is there a new test that would fail without this fix?
• Does test cover the reported bug scenario?
• Are related edge cases tested?

✅ Side Effects

• Could this break existing functionality?
• Are there similar code paths that need checking?
• Does this change behavior in unexpected ways?

✅ Fix Scope

• Is the fix appropriately scoped (not too broad, not too narrow)?
• Are all instances of the bug fixed?
• Any related bugs discovered during investigation?

What to SKIP

❌ Full Architecture Review - Unless fix reveals architectural problems ❌ Comprehensive Testing Review - Focus on regression tests, not entire test suite ❌ Major Refactoring Suggestions - Unless directly related to preventing similar bugs

Red Flags

🚩 No test for the bug - How will we prevent regression? 🚩 Fix doesn't match root cause - Is this fixing symptoms? 🚩 Broad changes beyond the bug - Should this be split into separate PRs? 🚩 Similar patterns elsewhere - Should those be fixed too?

Key Questions to Ask

Use reference/review-psychology.md for phrasing:

• "Can we add a test that would fail without this fix?"
• "I see this pattern in [other file] - does it have the same issue?"
• "Is this fixing the root cause or masking the symptom?"
• "Could this change affect [related feature]?"

Prioritizing Findings

Use reference/priority-framework.md to classify findings as Critical/Important/Suggested/Optional.

Output Format

See examples/review-outputs.md for the required output format and inline comment structure.

Example Review

**Overall Assessment:** APPROVE

See inline comments for suggested improvements.

Inline comment examples:

**data/auth/BiometricRepository.kt:120** - SUGGESTED: Extract null handling

<details>
<summary>Details</summary>

Root cause analysis: BiometricPrompt result was nullable but code assumed non-null, causing crash on cancellation (PM-12345).

Consider extracting null handling pattern:

\```kotlin
private fun handleBiometricResult(result: BiometricPrompt.AuthenticationResult?): AuthResult {
    return result?.let { AuthResult.Success(it) } ?: AuthResult.Cancelled
}
\```

This pattern could be reused if we add other biometric auth points.
</details>

**app/auth/BiometricViewModel.kt:89** - SUGGESTED: Add regression test

<details>
<summary>Details</summary>

Add test for cancellation scenario to prevent regression:

\```kotlin
@Test
fun `when biometric cancelled then returns cancelled state`() = runTest {
    coEvery { repository.authenticate() } returns Result.failure(CancelledException())
    viewModel.onBiometricAuth()
    assertEquals(AuthState.Cancelled, viewModel.state.value)
}
\```

This prevents regression of the bug just fixed.
</details>