Review scope

Review Scope

Overview

Determine the appropriate scope for code review based on change size.

Core principle: Major changes need broader review. Minor changes need focused review.

Question to answer: Is this a minor change or a major change?

Classification

Minor Change

Review only NEW code.

Indicators:

Indicator	Example
Few files changed	1-3 files
Isolated change	Single function modification
No API changes	Internal implementation only
No new dependencies	Uses existing code
Localized impact	Doesn't affect other modules

Examples:

• Bug fix in single function
• Adding a field to existing model
• Small feature in existing module
• Updating constants/config
• Fixing typos

Review scope:

• Changed lines only
• New tests for changes
• Immediate function context

Major Change

Review NEW code AND IMPACTED code.

Indicators:

Indicator	Example
Many files changed	4+ files
Cross-cutting change	Touches multiple modules
API changes	Public interface modified
New dependencies	Adds libraries or modules
Behavioral changes	Affects existing functionality
Architecture impact	Changes patterns or structure

Examples:

• New feature spanning multiple files
• Refactoring core module
• Changing authentication flow
• Adding new service layer
• Modifying database schema

Review scope:

• All changed code
• All code that calls changed code
• All code that changed code calls
• Integration points
• End-to-end flow

Decision Flow

┌─────────────────────────────────────┐
│         FILES CHANGED               │
└─────────────────┬───────────────────┘
                  │
                  ▼
        ┌─────────────────┐
        │ > 3 files?      │
        └────────┬────────┘
                 │
       ┌─────────┴─────────┐
       │                   │
      Yes                  No
       │                   │
       ▼                   ▼
   MAJOR             ┌─────────────────┐
                     │ Public API      │
                     │ changed?        │
                     └────────┬────────┘
                              │
                     ┌────────┴────────┐
                     │                 │
                    Yes                No
                     │                 │
                     ▼                 ▼
                  MAJOR          ┌─────────────────┐
                                 │ Behavioral      │
                                 │ change?         │
                                 └────────┬────────┘
                                          │
                                 ┌────────┴────────┐
                                 │                 │
                                Yes                No
                                 │                 │
                                 ▼                 ▼
                              MAJOR             MINOR

Finding Impacted Code

For major changes, identify impacted code:

Find Callers

# Find all files that import the changed module
grep -r "import.*from.*'./changed-module'" src/

# Find all usages of changed function
grep -r "changedFunction" src/

Find Dependencies

# What does the changed code import?
grep "import" src/changed-file.ts

# Trace the dependency chain

Review Call Chain

Changed function
     │
     ├── Called by: parentFunction()  ← Review this
     │        │
     │        └── Called by: grandparent()  ← Review if behavior changed
     │
     └── Calls: childFunction()  ← Review if inputs changed
              │
              └── Calls: database.save()  ← Review if data shape changed

Scope Documentation

Before starting review, document scope:

Minor Change

## Review Scope: MINOR

**Changed files:**
- src/utils/format.ts (10 lines)

**Review focus:**
- New formatDate() function
- Associated tests

**Not reviewing:**
- Callers of format module (unchanged behavior)

Major Change

## Review Scope: MAJOR

**Changed files:**
- src/services/auth.ts
- src/middleware/authenticate.ts
- src/routes/login.ts
- src/models/session.ts
- tests/auth.test.ts

**Impacted code to review:**
- src/routes/protected/* (use auth middleware)
- src/services/user.ts (calls auth service)

**Integration points:**
- Login flow end-to-end
- Session management
- Protected route access

**Review focus:**
- All changed code
- All callers of auth service
- Auth middleware consumers
- Session handling throughout

Checklists by Scope

Minor Change Review

• Changed lines reviewed
• New code meets all 7 criteria
• New tests exist
• Existing tests still pass
• No unintended side effects

Major Change Review

All of minor, PLUS:

• All callers identified
• Caller behavior reviewed
• All callees identified
• Integration points reviewed
• End-to-end flow verified
• Impacted tests reviewed
• No regression in impacted areas

Edge Cases

When Uncertain

If unsure whether change is minor or major:

Default to major. Better to over-review than miss issues.

Small Change with Large Impact

Sometimes few lines have large impact:

// Small change, but MAJOR scope
// Changing default timeout affects all HTTP calls
const DEFAULT_TIMEOUT = 30000; // Was 5000

Review all code affected by the changed behavior.

Large Refactor with No Behavior Change

Many files changed but pure refactor:

// Renamed variable across 20 files
// No behavior change

Still MAJOR for structural review, but behavioral review is lighter.

Integration

This skill is called by:

• issue-driven-development - Step 9
• comprehensive-review - Before starting review

This skill informs:

• How much code to review
• Which tests to examine
• What integration points to check