Bounded Contexts Analyzer

Overview

This skill analyzes PHP DDD projects for bounded context boundary issues, cross-context coupling, and context mapping violations.

Bounded Context Concepts

Concept	Definition	Violation Indicator
Bounded Context	Explicit boundary with its own domain model	Missing namespace separation
Ubiquitous Language	Consistent terminology within context	Same term, different meanings
Context Map	Relationships between contexts	Unclear dependencies
Anti-Corruption Layer	Translation between contexts	Direct foreign model usage
Shared Kernel	Deliberately shared code	Unintentional sharing
Published Language	Public API contracts	Breaking changes

Detection Patterns

Phase 1: Context Discovery

# Identify bounded contexts from directory structure
Glob: **/src/**/Domain/*
Glob: **/src/**/Context/*
Glob: **/src/**/Bounded/*
Glob: **/src/**/Module/*

# Namespace-based contexts
Grep: "namespace.*\\\\Domain\\\\|namespace.*\\\\Context\\\\" --glob "**/*.php"

# Composer autoload namespaces
Read: composer.json (check autoload paths for context namespaces)

Context Indicators:

• Top-level namespace under src/ (e.g., Order, User, Payment)
• Explicit Domain/ subfolder per context
• BoundedContext/ or Context/ folder structure

Phase 2: Cross-Context Coupling Detection

Direct Cross-Context Imports

# Find cross-context imports (most critical)
# Pattern: Context A importing from Context B's Domain layer

# Order context importing User domain
Grep: "use Order\\\\.*\\\\Domain" --glob "**/User/**/*.php"
Grep: "use User\\\\.*\\\\Domain" --glob "**/Order/**/*.php"

# General pattern: Domain layer importing another Domain
Grep: "use [A-Z][a-z]+\\\\Domain\\\\" --glob "**/Domain/**/*.php"

# Direct entity references across contexts
Grep: "use.*\\\\Entity\\\\(?!.*\\\\self)" --glob "**/Domain/**/*.php"

Foreign Aggregate References

# Aggregates referencing foreign entities directly
Grep: "private.*[A-Z][a-z]+Entity\|private readonly [A-Z][a-z]+" --glob "**/Aggregate/**/*.php"

# Should use ID references only
# Good: private UserId $userId
# Bad: private User $user (from another context)

# Detect direct object references vs ID references
Grep: "\\$user[^I]|\\$order[^I]|\\$customer[^I]" --glob "**/Domain/**/*.php"

Shared Repository Usage

# Repository from one context used in another
Grep: "UserRepositoryInterface" --glob "**/Order/**/*.php"
Grep: "OrderRepositoryInterface" --glob "**/User/**/*.php"

# Generic repository pattern violations
Grep: "RepositoryInterface" --glob "**/*.php"
# Check if implementations span contexts

Phase 3: Shared Kernel Analysis

# Identify potential shared kernel (common code between contexts)
Glob: **/Shared/**/*.php
Glob: **/Common/**/*.php
Glob: **/Core/**/*.php
Glob: **/SharedKernel/**/*.php

# Find duplicated Value Objects across contexts
# Same class name in multiple contexts
Glob: **/Domain/**/Email.php
Glob: **/Domain/**/Money.php
Glob: **/Domain/**/Address.php

# Shared events
Grep: "class.*Event.*implements|extends.*Event" --glob "**/Shared/**/*.php"

Shared Kernel Rules:

• Must be explicitly designated
• Minimal and stable
• Changes require agreement from all context owners
• Should contain only Value Objects, not Entities

Phase 4: Context Map Relationships

Upstream/Downstream Detection

# Event publishers (upstream)
Grep: "EventDispatcher|MessageBus|publish\(" --glob "**/Domain/**/*.php"
Grep: "class.*Event\s*\{|final readonly class.*Event" --glob "**/Domain/**/*.php"

# Event subscribers (downstream)
Grep: "EventSubscriber|MessageHandler|Listener" --glob "**/*.php"
Grep: "function __invoke\(.*Event" --glob "**/*.php"

# Check which context publishes and which subscribes

Customer/Supplier Relationships

# API clients (customer role)
Grep: "ApiClient|HttpClient|RestClient" --glob "**/Infrastructure/**/*.php"

# API providers (supplier role)
Grep: "Controller|Action|Endpoint" --glob "**/Presentation/**/*.php"

Anti-Corruption Layer Detection

# ACL presence
Glob: **/AntiCorruption/**/*.php
Glob: **/ACL/**/*.php
Glob: **/Adapter/**/*.php
Glob: **/Translator/**/*.php

# Missing ACL (direct external model usage)
Grep: "use External\\\\|use ThirdParty\\\\|use Legacy\\\\" --glob "**/Domain/**/*.php"

Phase 5: Ubiquitous Language Analysis

# Find same term with different meanings
# Example: "Account" in User context vs Payment context

# Find class with same name in different contexts
Glob: **/User/**/Account.php
Glob: **/Payment/**/Account.php
Glob: **/Billing/**/Account.php

# Find similar entity names
Glob: **/Domain/**/User.php
Glob: **/Domain/**/Customer.php
Glob: **/Domain/**/Client.php

# Inconsistent naming
Grep: "class Order|class Purchase|class Sale" --glob "**/Domain/**/*.php"

Report Format

# Bounded Context Analysis Report

## Context Map

```mermaid
graph TB
    subgraph "Order Context"
        O_Domain[Domain]
        O_App[Application]
    end

    subgraph "User Context"
        U_Domain[Domain]
        U_App[Application]
    end

    subgraph "Payment Context"
        P_Domain[Domain]
        P_App[Application]
    end

    subgraph "Shared Kernel"
        SK[Money, Currency]
    end

    O_Domain -->|"uses ID only"| U_Domain
    O_Domain -->|"publishes events"| P_Domain
    O_Domain --> SK
    U_Domain --> SK
    P_Domain --> SK

Detected Contexts

Context	Location	Entities	Events	Dependencies
Order	src/Order/	5	8	User (ID), Payment (event)
User	src/User/	3	4	None
Payment	src/Payment/	4	6	Order (event)
Shared	src/Shared/	0	0	All contexts

Critical Issues

BC-001: Cross-Context Entity Reference

• File: src/Order/Domain/Entity/Order.php:15
• Issue: Direct reference to User entity instead of UserId
• Code: private User $user (from User context)
• Expected: private UserId $userId
• Impact: Tight coupling, breaks context isolation
• Refactoring: Replace with ID reference, use ACL if needed
• Skills: create-value-object (for UserId), create-anti-corruption-layer

BC-002: Missing Anti-Corruption Layer

• File: src/Payment/Infrastructure/Gateway/StripeGateway.php
• Issue: Stripe models used directly in domain
• Code: use Stripe\PaymentIntent;
• Impact: External API changes affect domain
• Refactoring: Create PaymentIntent adapter/translator
• Skills: create-anti-corruption-layer

BC-003: Unintended Shared Kernel

• Files:
  • src/Order/Domain/ValueObject/Address.php
  • src/User/Domain/ValueObject/Address.php
• Issue: Duplicated Address VO without explicit sharing
• Impact: Inconsistent behavior, maintenance burden
• Refactoring: Either consolidate to Shared Kernel or differentiate
• Skills: create-value-object

Warning Issues

BC-004: Ambiguous Ubiquitous Language

• Context 1: src/User/ uses Account for user profile
• Context 2: src/Payment/ uses Account for financial account
• Issue: Same term, different meanings
• Refactoring: Rename to UserProfile and PaymentAccount

BC-005: Missing Published Language

• Context: Order
• Issue: No explicit contract for inter-context communication
• Events published: 8
• Documented: 0
• Refactoring: Create event schema documentation

BC-006: Upstream Without Events

• Context: User (upstream)
• Downstream: Order, Payment (via direct queries)
• Issue: Downstream contexts query User directly
• Refactoring: User should publish events, downstreams react

Context Relationship Matrix

From \ To	Order	User	Payment	Shared
Order	-	ID ref	Events	Uses
User	-	-	-	Uses
Payment	Queries	Queries	-	Uses
Shared	-	-	-	-

Legend:

• ID ref: References only by ID (good)
• Events: Async event communication (good)
• Queries: Direct query (warning)
• Uses: Shared kernel usage (acceptable)

Recommendations

Immediate Actions

1. Replace direct entity references with ID Value Objects
2. Add ACL for external service integrations

Short-term

3. Document published language (event contracts)
4. Consolidate or differentiate duplicated VOs

Long-term

5. Consider event-driven communication between contexts
6. Review shared kernel scope

## Context Integration Patterns

### Recommended Patterns

| Pattern | When to Use | Skills |
|---------|-------------|--------|
| ID Reference | Entity association across contexts | `create-value-object` |
| Domain Events | Async communication | `create-domain-event` |
| ACL | External systems, legacy | `create-anti-corruption-layer` |
| Shared Kernel | Common VOs (Money, etc.) | `create-value-object` |
| Published Language | Public contracts | Documentation |

### Anti-patterns

| Anti-pattern | Issue | Remediation |
|--------------|-------|-------------|
| Direct Entity Reference | Tight coupling | Use ID + resolve via query |
| Shared Entities | Ownership unclear | Split or explicit ownership |
| Cross-Context Repository | Boundary violation | Use events or ACL |
| Synchronous Cross-Context Calls | Temporal coupling | Use async events |

## Quick Analysis Commands

```bash
# Detect bounded contexts
echo "=== Bounded Contexts ===" && \
find src -maxdepth 2 -type d -name "Domain" && \
echo "=== Cross-Context Imports ===" && \
for ctx in $(find src -maxdepth 1 -type d | tail -n +2); do \
  name=$(basename $ctx); \
  grep -rn "use .*\\\\Domain\\\\" --include="*.php" "$ctx" | grep -v "use $name"; \
done && \
echo "=== Shared Kernel ===" && \
find src -type d -name "Shared" -o -name "Common" -o -name "Core"

Integration

Works with:

• ddd-auditor — Domain model quality
• structural-auditor — Layer violations
• ddd-generator — Generate missing components

References

• "Domain-Driven Design" (Eric Evans) — Chapter 14: Context Mapping
• "Implementing Domain-Driven Design" (Vaughn Vernon) — Chapter 3: Context Maps
• Strategic DDD patterns documentation