avoiding-false-positives

name	avoiding-false-positives
description	Use this skill to validate findings during a code review. For each finding, run the rejection criteria and verification checks. If a finding fails any check, drop it.

Validating Findings

Rejection Criteria

A finding is a false positive — drop it — if ANY of the following are true:

• Pre-existing — code existed before this PR and was not modified by this change
• Not actually buggy — appears wrong but is correct (e.g., variable IS defined, logic DOES produce correct results)
• Pedantic nitpick — a senior engineer would not flag this in a real review
• Linter-catchable — a linter or type checker will catch this; do not duplicate their work
• Generic concern — "lacks test coverage", "general security issue" without a specific, traceable problem
• Explicitly silenced — lint ignore comments, pragma suppressions, or documented exceptions
• Handled elsewhere — error boundaries, middleware, validators, or framework guarantees make the issue moot

Verification Checks

For each finding that passes rejection criteria, verify ALL three:

1. Can you trace the execution path showing incorrect behavior?
2. Is this handled elsewhere (error boundaries, middleware, validators)?
3. Are you certain about framework behavior, API contracts, and language semantics?

If you cannot confidently answer all three, drop the finding.

Patterns to Recognize (DO NOT flag)

1. Intentional simplicity - Not every function needs error handling if caller handles it
2. Framework conventions - React hooks, dependency injection, ORM patterns have specific rules
3. Test code - Different standards apply (hardcoded values, no error handling often OK)
4. Generated code - Migrations, API clients, proto files (only review if hand-edited)
5. Copied patterns - If code matches existing patterns in codebase, consistency > "better" approach
6. Automated dependency updates - Renovate/Dependabot minor/patch updates to existing dependencies with passing CI are routine Stage 5 monitoring
7. Lock file regeneration - A single manifest change can produce thousands of lock file diff lines; this is normal and not a review concern

When uncertain about a pattern, search the codebase for similar examples before flagging.

Codebase Conventions

1. Check existing patterns - How does this codebase handle similar cases?
2. Respect established conventions - Even if non-standard, consistency > perfection
3. Don't flag convention violations unless they cause bugs or security issues

Examples:

• Codebase uses any types extensively → Don't flag individual uses
• Codebase has no error handling in services → Don't flag one missing try-catch
• Consistency matters more than isolated improvements

Common False Positives

Do NOT flag when handled elsewhere or guaranteed by framework:

• Null checks: Language/framework ensures non-null, or prior validation occurred
• Error handling: Error boundaries exist, function designed to throw, or caller handles
• Race conditions: Framework synchronizes (React state, DB transactions), or operations idempotent
• Performance: Data bounded (<100 items), runs once at startup, no profiling evidence
• Security: Framework sanitizes (parameterized queries, JSX escaping), or API layer validates
• Lock file churn: Large lock file diffs from a single manifest change are expected behavior, not a review concern

When uncertain, assume the developer knows something you don't.