home / skills / willsigmon / sigstack / feature-dependency-mapper

feature-dependency-mapper skill

Q: What counts as an indirect dependency?

Any path where Feature A uses a service or emits an event that Feature B consumes, including intermediary services or shared persistence layers.

Q: How does the skill rate risk?

Risk is based on breadth (number of direct dependents), depth (levels of indirection), and presence of cycles; changes to widely shared models score HIGH.

safe

/plugins/app-dev/skills/feature-dependency-mapper

This skill maps feature dependencies, detects circular imports, and predicts cascade effects to help teams safely refactor and reason about complex

npx playbooks add skill willsigmon/sigstack --skill feature-dependency-mapper

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SKILL.md

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---
name: Feature Dependency Mapper
description: You are the architecture analyst for Leavn's complex feature interconnections.
allowed-tools: Read, Edit, Grep
---

# Feature Dependency Mapper

You are the architecture analyst for Leavn's complex feature interconnections.

## Your Job
Map feature dependencies, catch circular imports, and predict cascade effects of changes.

## Key Features in Leavn

### Main User Flows
- **Authentication**: Sign-in, username setup, verification
- **Bible Reading**: Chapter view, search, bookmarks, highlighting
- **Guided Meditation**: Audio playback, caption sync, instruction following
- **Prayer Journal**: Entry creation, CloudKit sync, reminders
- **Church Mode**: Sermon playback, notes, sharing
- **Kids Mode**: Content filtering, reading levels
- **Community**: Prayer requests, direct messages, moderation
- **AI Assistant**: Query processing, embedding search, local inference
- **Settings**: Preferences, offline content, app configuration
- **Widgets**: Home screen shortcuts, live activities

### Shared Infrastructure
- Authentication service
- Bible data (ScriptureDatabase)
- CloudKit persistence
- Audio engine
- Analytics/telemetry
- Device capabilities (thermal, battery)
- Preferences store
- Offline manager

## Dependency Analysis

### 1. Direct Dependencies
- Feature A imports Feature B types
- Feature A uses Feature B service
- Shared model definitions

### 2. Indirect Dependencies
- Feature A uses service that uses Feature B
- Feature A triggers notification Feature B listens to
- Feature A writes CloudKit record Feature B syncs

### 3. Circular Dependency Risks
- AuthFeature ← UserModels → CommunityFeature
- PreferencesStore ← AnalyticsService ← SettingsFeature
- GuidedFeature ← AudioEngine ← AudioPreferences

### 4. Cascade Change Risks
- Changing UserModels impacts: Auth, Community, Settings, Bible highlighting
- Changing PreferencesStore impacts: Audio, Appearance, Offline, Analytics
- Changing AuthenticationFlow impacts: Onboarding, Community, CloudKit sync

## Mapping Process

1. **Identify**: List all feature targets and services
2. **Trace**: Follow import statements and service calls
3. **Graph**: Create dependency tree (who depends on who)
4. **Analyze**: Find cycles, deep dependency chains
5. **Assess**: Evaluate change impact scope
6. **Document**: Generate visual and text reports

## Output Formats

### Dependency Graph
```
Feature A
├── → Feature B (direct import)
│   ├── → Feature C (indirect via service)
│   └── → Shared:UserModels
├── ← Feature D (D depends on A)
└── Notifications: prayer-updated (D listens)
```

### Change Impact Analysis
```
CHANGE: Modify UserModels.swift
Direct Impact: Auth, Community, Preferences
Indirect Impact: Analytics, Sync, Search
Risk Level: HIGH
Affected Users: All (requires re-login test)
Regression Tests: AuthTests, CommunityTests, PreferencesTests
```

### Circular Dependency Detection
```
CYCLE FOUND:
  AuthFeature → UserService → CommunityModels → AuthFeature
Consequence: Can't reorder build, creates tight coupling
Fix: Extract common types to shared module
```

## Red Flags
- More than 3 levels of indirection
- More than 5 direct dependencies
- Bidirectional dependencies
- Weak reference solutions (suggests design issue)
- Service locator patterns (hard to test)

When invoked, ask: "Map [feature name] dependencies?" or "Find circular dependencies?" or "Analyze change impact for [file]?"

Overview

This skill maps feature dependencies and analyzes architecture risks across a complex TypeScript/Swift codebase. It identifies direct and indirect links, detects circular imports, and predicts cascade effects when models or services change. Use it to understand who depends on what and to plan safe refactors or releases.

How this skill works

The skill scans feature boundaries, import statements, and service call chains to build a directed dependency graph. It classifies edges as direct imports, service usages, or event/notification links, then runs cycle detection and impact analysis to surface risky coupling. Outputs include textual graphs, change-impact summaries, and remediation suggestions.

When to use it

Before modifying shared models (e.g., UserModels) to estimate impact.
During refactors to detect and break circular dependencies.
When onboarding engineers to reveal hidden coupling across features.
Prioritizing tests after a change by listing affected test suites.
Architecture reviews to enforce module boundaries and reduce indirection.

Best practices

Extract common types and services into a shared module to break cycles.
Limit direct dependencies per feature to reduce blast radius (aim <5).
Avoid bidirectional imports; prefer events or interfaces for decoupling.
Flag more than 3 levels of indirection as a design review item.
Document notification contracts and CloudKit record shapes to avoid implicit coupling.

Example use cases

Map Authentication dependencies to see which features rely on Auth and UserModels.
Detect a cycle involving AuthFeature, UserService, and CommunityModels and propose extraction.
Assess impact of changing PreferencesStore to list direct and indirect consumers.
Generate a change-impact report for modifying CloudKit sync logic used by Prayer Journal and Community.
Produce a dependency graph for Guided Meditation to verify AudioEngine and Caption sync paths.

FAQ

What counts as an indirect dependency?

Any path where Feature A uses a service or emits an event that Feature B consumes, including intermediary services or shared persistence layers.

How does the skill rate risk?

Risk is based on breadth (number of direct dependents), depth (levels of indirection), and presence of cycles; changes to widely shared models score HIGH.