Common Domain Component Detection

Overview

This public intake copy packages

packages/skills-catalog/skills/(architecture)/component-common-domain-detection

https://github.com/tech-leads-club/agent-skills

Use it when the operator needs the upstream workflow, support files, and repository context to stay intact while the public validator and private enhancer continue their normal downstream flow.

This intake keeps the copied upstream files intact and uses

metadata.json

ORIGIN.md

Common Domain Component Detection This skill identifies common domain functionality that is duplicated across multiple components and suggests consolidation opportunities to reduce duplication and improve maintainability.

Imported source sections that did not map cleanly to the public headings are still preserved below or in the support files. Notable imported sections: How to Use, Core Concepts, Common Namespace Patterns Found, Shared Classes Found, Functionality Analysis, Coupling Impact Analysis.

When to Use This Skill

Use this section as the trigger filter. It should make the activation boundary explicit before the operator loads files, runs commands, or opens a pull request.

• After identifying and sizing components (Pattern 1)
• Before flattening components (Pattern 3)
• When planning to reduce code duplication
• Analyzing shared domain logic across the codebase
• Preparing for component consolidation
• Identifying candidates for shared services or libraries

Operating Table

metadata.json

ORIGIN.md

QUICK-REFERENCE.md

README.md

## Related Skills

Workflow

This workflow is intentionally editorial and operational at the same time. It keeps the imported source useful to the operator while still satisfying the public intake standards that feed the downstream enhancer flow.

1. Extract leaf nodes from all component namespaces
2. Example: services/billing/notification → notification
3. Example: services/ticket/notification → notification
4. Group by common leaf nodes
5. Find components with same leaf node name
6. Example: All components ending in .notification
7. Filter out infrastructure patterns

Imported Workflow Notes

Imported: Analysis Process

Phase 1: Identify Common Namespace Patterns

Scan component namespaces for common leaf node names:

1. Extract leaf nodes from all component namespaces

   • Example:

     services/billing/notification

     →

     notification

   • Example:

     services/ticket/notification

     →

     notification

2. Group by common leaf nodes

   • Find components with same leaf node name
   • Example: All components ending in

     .notification

3. Filter out infrastructure patterns

   • Exclude:

     .util

     ,

     .helper

     ,

     .common

     (usually infrastructure)
   • Focus on:

     .notification

     ,

     .audit

     ,

     .validation

     ,

     .formatting

Example Output:

#### Imported: Next Steps

After identifying common domain components:

1. **Apply Flatten Components Pattern** - Remove orphaned classes
2. **Apply Determine Component Dependencies Pattern** - Analyze coupling
3. **Create Component Domains** - Group components into domains
4. **Plan Consolidation** - Execute consolidation recommendations

#### Imported: How to Use

### Quick Start

Request analysis of your codebase:

- **"Find common domain functionality across components"**
- **"Identify duplicate domain logic that should be consolidated"**
- **"Detect shared classes used across multiple components"**
- **"Analyze consolidation opportunities for common components"**

### Usage Examples

**Example 1: Find Common Functionality**

User: "Find common domain functionality across components"

The skill will:

1. Scan component namespaces for common patterns
2. Detect shared classes used across components
3. Identify duplicate domain logic
4. Analyze coupling impact of consolidation
5. Suggest consolidation opportunities

**Example 2: Detect Duplicate Notification Logic**

User: "Are there multiple notification components that should be consolidated?"

The skill will:

1. Find all components with notification-related names
2. Analyze their functionality and dependencies
3. Calculate coupling impact if consolidated
4. Recommend consolidation approach

**Example 3: Analyze Shared Classes**

User: "Find classes that are shared across multiple components"

The skill will:

1. Identify classes imported/used by multiple components
2. Classify as domain vs infrastructure functionality
3. Suggest consolidation or shared library approach
4. Assess impact on coupling

### Step-by-Step Process

1. **Scan Components**: Identify components with common namespace patterns
2. **Detect Shared Code**: Find classes/files used across components
3. **Analyze Functionality**: Determine if functionality is truly common
4. **Assess Coupling**: Calculate coupling impact before consolidation
5. **Recommend Actions**: Suggest consolidation or shared library approach

## Examples

### Example 1: Ask for the upstream workflow directly

```text
Use @component-common-domain-detection to handle <task>. Start from the copied upstream workflow, load only the files that change the outcome, and keep provenance visible in the answer.

Explanation: This is the safest starting point when the operator needs the imported workflow, but not the entire repository.

Example 2: Ask for a provenance-grounded review

Review @component-common-domain-detection against metadata.json and ORIGIN.md, then explain which copied upstream files you would load first and why.

Explanation: Use this before review or troubleshooting when you need a precise, auditable explanation of origin and file selection.

Example 3: Narrow the copied support files before execution

Use @component-common-domain-detection for <task>. Load only the copied references, examples, or scripts that change the outcome, and name the files explicitly before proceeding.

Explanation: This keeps the skill aligned with progressive disclosure instead of loading the whole copied package by default.

Example 4: Build a reviewer packet

Review @component-common-domain-detection using the copied upstream files plus provenance, then summarize any gaps before merge.

Explanation: This is useful when the PR is waiting for human review and you want a repeatable audit packet.

Best Practices

Treat the generated public skill as a reviewable packaging layer around the upstream repository. The goal is to keep provenance explicit and load only the copied source material that materially improves execution.

• Distinguish domain from infrastructure functionality
• Analyze coupling impact before consolidating
• Consider both shared service and shared library approaches
• Look for namespace patterns AND shared classes
• Verify functionality is truly similar before consolidating
• Calculate coupling metrics (CA) before and after
• Don't consolidate infrastructure functionality (handled separately)

Imported Operating Notes

Imported: Best Practices

Do's ✅

• Distinguish domain from infrastructure functionality
• Analyze coupling impact before consolidating
• Consider both shared service and shared library approaches
• Look for namespace patterns AND shared classes
• Verify functionality is truly similar before consolidating
• Calculate coupling metrics (CA) before and after

Don'ts ❌

• Don't consolidate infrastructure functionality (handled separately)
• Don't consolidate without analyzing coupling impact
• Don't assume all common patterns should be consolidated
• Don't ignore differences in functionality
• Don't consolidate if coupling increase is too high
• Don't mix domain and infrastructure in same analysis

Troubleshooting

Problem: The operator skipped the imported context and answered too generically

Symptoms: The result ignores the upstream workflow in

packages/skills-catalog/skills/(architecture)/component-common-domain-detection

metadata.json

ORIGIN.md

Problem: The imported workflow feels incomplete during review

Symptoms: Reviewers can see the generated

SKILL.md

Problem: The task drifted into a different specialization

Symptoms: The imported skill starts in the right place, but the work turns into debugging, architecture, design, security, or release orchestration that a native skill handles better. Solution: Use the related skills section to hand off deliberately. Keep the imported provenance visible so the next skill inherits the right context instead of starting blind.

Related Skills

• @accessibility

  - Use when the work is better handled by that native specialization after this imported skill establishes context.

• @ai-cold-outreach

  - Use when the work is better handled by that native specialization after this imported skill establishes context.

• @ai-pricing

  - Use when the work is better handled by that native specialization after this imported skill establishes context.

• @ai-sdr

  - Use when the work is better handled by that native specialization after this imported skill establishes context.

Additional Resources

Use this support matrix and the linked files below as the operator packet for this imported skill. They should reflect real copied source material, not generic scaffolding.

references

references/n/a

examples

examples/n/a

scripts

scripts/n/a

agents

agents/n/a

assets

assets/n/a

• QUICK-REFERENCE.md
• README.md

Imported Reference Notes

Imported: Core Concepts

Domain vs Infrastructure Functionality

Domain Functionality (candidates for consolidation):

• Business processing logic (notification, validation, auditing, formatting)
• Common to some processes, not all
• Examples: Customer notification, ticket auditing, data validation

Infrastructure Functionality (usually not consolidated here):

• Operational concerns (logging, metrics, security)
• Common to all processes
• Examples: Logging, authentication, database connections

Common Domain Patterns

Common domain functionality often appears as:

1. Namespace Patterns: Components ending in same leaf node

   • *.notification

     ,

     *.audit

     ,

     *.validation

     ,

     *.formatting

   • Example:

     TicketNotification

     ,

     BillingNotification

     ,

     SurveyNotification

2. Shared Classes: Same class used across multiple components

   • Example:

     SMTPConnection

     used by 5 different components
   • Example:

     AuditLogger

     used by multiple domain components

3. Similar Functionality: Different components doing similar things

   • Example: Multiple components sending emails with slight variations
   • Example: Multiple components writing audit logs

Consolidation Approaches

Shared Service:

• Common functionality becomes a separate service
• Other components call this service
• Good for: Frequently changing logic, complex operations

Shared Library:

• Common code packaged as library (JAR, DLL, npm package)
• Components import and use the library
• Good for: Stable functionality, simple utilities

Component Consolidation:

• Merge multiple components into one
• Good for: Highly related functionality, low coupling impact

Imported: Common Namespace Patterns Found

Notification Components:

• services/customer/notification
• services/ticket/notification
• services/survey/notification

Audit Components:

• services/billing/audit
• services/ticket/audit
• services/survey/audit

### Phase 2: Detect Shared Classes

Find classes/files used across multiple components:

1. **Scan imports/dependencies** in each component
   - Track which classes are imported from where
   - Note classes used by multiple components

2. **Identify shared classes**
   - Classes imported by 2+ components
   - Exclude infrastructure classes (Logger, Config, etc.)

3. **Classify as domain vs infrastructure**
   - Domain: Business logic classes (SMTPConnection, AuditLogger)
   - Infrastructure: Technical utilities (Logger, DatabaseConnection)

**Example Output**:

```markdown

#### Imported: Shared Classes Found

**Domain Classes**:

- `SMTPConnection` - Used by 5 components (notification-related)
- `AuditLogger` - Used by 8 components (audit-related)
- `DataFormatter` - Used by 3 components (formatting-related)

**Infrastructure Classes** (exclude from consolidation):

- `Logger` - Used by all components (infrastructure)
- `Config` - Used by all components (infrastructure)

Phase 3: Analyze Functionality Similarity

For each group of common components:

1. Examine functionality

   • Read source code of each component
   • Identify what each component does
   • Note similarities and differences

2. Assess consolidation feasibility

   • Are differences minor (configurable)?
   • Can differences be abstracted?
   • Is functionality truly the same?

3. Calculate coupling impact

   • Count incoming dependencies (afferent coupling) before consolidation
   • Estimate incoming dependencies after consolidation
   • Compare total coupling levels

Example Analysis:

#### Imported: Functionality Analysis

**Notification Components**:

- CustomerNotification: Sends billing notifications
- TicketNotification: Sends ticket assignment notifications
- SurveyNotification: Sends survey emails

**Similarities**: All send emails to customers
**Differences**: Email content/templates, triggers

**Consolidation Feasibility**: ✅ High

- Differences are in content, not mechanism
- Can be abstracted with templates/context

Phase 4: Assess Coupling Impact

Before recommending consolidation, analyze coupling:

1. Calculate current coupling

   • Count components using each notification component
   • Sum total incoming dependencies

2. Estimate consolidated coupling

   • Count components that would use consolidated component
   • Compare to current total

3. Evaluate coupling increase

   • Is consolidated component too coupled?
   • Does it create a bottleneck?
   • Is coupling increase acceptable?

Example Coupling Analysis:

#### Imported: Coupling Impact Analysis

**Before Consolidation**:

- CustomerNotification: Used by 2 components (CA = 2)
- TicketNotification: Used by 2 components (CA = 2)
- SurveyNotification: Used by 1 component (CA = 1)
- **Total CA**: 5

**After Consolidation**:

- Notification: Used by 5 components (CA = 5)
- **Total CA**: 5 (same!)

**Verdict**: ✅ No coupling increase, safe to consolidate

Phase 5: Recommend Consolidation Approach

Based on analysis, recommend approach:

Shared Service (if):

• Functionality changes frequently
• Complex operations
• Needs independent scaling
• Multiple deployment units will use it

Shared Library (if):

• Stable functionality
• Simple utilities
• Compile-time dependency acceptable
• No need for independent deployment

Component Consolidation (if):

• Highly related functionality
• Low coupling impact
• Same deployment unit acceptable

Imported: Output Format

Common Domain Components Report

#### Imported: Common Domain Components Found

### Notification Functionality

**Components**:

- services/customer/notification (2% - 1,433 statements)
- services/ticket/notification (2% - 1,765 statements)
- services/survey/notification (2% - 1,299 statements)

**Shared Classes**: SMTPConnection (used by all 3)

**Functionality Analysis**:

- All send emails to customers
- Differences: Content/templates, triggers
- Consolidation Feasibility: ✅ High

**Coupling Analysis**:

- Before: CA = 2 + 2 + 1 = 5
- After: CA = 5 (no increase)
- Verdict: ✅ Safe to consolidate

**Recommendation**: Consolidate into `services/notification`

- Approach: Shared Service
- Expected Size: ~4,500 statements (5% of codebase)
- Benefits: Reduced duplication, easier maintenance

Consolidation Opportunities Table

#### Imported: Consolidation Opportunities

| Common Functionality | Components   | Current CA | After CA | Feasibility | Recommendation                |
| -------------------- | ------------ | ---------- | -------- | ----------- | ----------------------------- |
| Notification         | 3 components | 5          | 5        | ✅ High     | Consolidate to shared service |
| Audit                | 3 components | 8          | 12       | ⚠️ Medium   | Consolidate, monitor coupling |
| Validation           | 2 components | 3          | 3        | ✅ High     | Consolidate to shared library |

Detailed Consolidation Plan

#### Imported: Consolidation Plan

### Priority: High

**Notification Components** → `services/notification`

**Steps**:

1. Create new `services/notification` component
2. Move common functionality from 3 components
3. Create abstraction for content/templates
4. Update dependent components to use new service
5. Remove old notification components

**Expected Impact**:

- Reduced code: ~4,500 statements consolidated
- Reduced duplication: 3 components → 1
- Coupling: No increase (CA stays at 5)
- Maintenance: Easier to maintain single component

### Priority: Medium

**Audit Components** → `services/audit`

**Steps**:
[Similar format]

**Expected Impact**:

- Coupling increase: CA 8 → 12 (monitor)
- Benefits: Reduced duplication

Imported: Analysis Checklist

Common Pattern Detection:

• Scanned all component namespaces for common leaf nodes
• Identified components with same ending names
• Filtered out infrastructure patterns
• Grouped similar components

Shared Class Detection:

• Scanned imports/dependencies in each component
• Identified classes used by multiple components
• Classified as domain vs infrastructure
• Documented shared class usage

Functionality Analysis:

• Examined source code of common components
• Identified similarities and differences
• Assessed consolidation feasibility
• Determined if differences can be abstracted

Coupling Assessment:

• Calculated current coupling (CA) for each component
• Estimated consolidated coupling
• Compared total coupling levels
• Evaluated if coupling increase is acceptable

Recommendations:

• Suggested consolidation approach (service/library/merge)
• Prioritized recommendations by impact
• Created consolidation plan with steps
• Estimated expected benefits and risks

Imported: Implementation Notes

For Node.js/Express Applications

Common patterns to look for:

services/
├── CustomerService/
│   └── notification.js      ← Common pattern
├── TicketService/
│   └── notification.js     ← Common pattern
└── SurveyService/
    └── notification.js      ← Common pattern

Shared Classes:

• Check

  require()

  statements
• Look for classes imported from other components
• Example:

  const SMTPConnection = require('../shared/SMTPConnection')

For Java Applications

Common patterns:

com.company.billing.audit     ← Common pattern
com.company.ticket.audit      ← Common pattern
com.company.survey.audit      ← Common pattern

Shared Classes:

• Check

  import

  statements
• Look for classes in common packages
• Example:

  import com.company.shared.AuditLogger

Detection Strategies

Namespace Pattern Detection:

// Extract leaf nodes from namespaces
function extractLeafNode(namespace) {
  const parts = namespace.split('/')
  return parts[parts.length - 1]
}

// Group by common leaf nodes
function groupByLeafNode(components) {
  const groups = {}
  components.forEach((comp) => {
    const leaf = extractLeafNode(comp.namespace)
    if (!groups[leaf]) groups[leaf] = []
    groups[leaf].push(comp)
  })
  return groups
}

Shared Class Detection:

// Find classes used by multiple components
function findSharedClasses(components) {
  const classUsage = {}
  components.forEach((comp) => {
    comp.imports.forEach((imp) => {
      if (!classUsage[imp]) classUsage[imp] = []
      classUsage[imp].push(comp.name)
    })
  })

  return Object.entries(classUsage)
    .filter(([cls, users]) => users.length > 1)
    .map(([cls, users]) => ({ class: cls, usedBy: users }))
}

Imported: Fitness Functions

After identifying common components, create automated checks:

Common Namespace Pattern Detection

// Alert if new components with common patterns are created
function checkCommonPatterns(components, exclusionList = []) {
  const leafNodes = {}
  components.forEach((comp) => {
    const leaf = extractLeafNode(comp.namespace)
    if (!exclusionList.includes(leaf)) {
      if (!leafNodes[leaf]) leafNodes[leaf] = []
      leafNodes[leaf].push(comp.name)
    }
  })

  return Object.entries(leafNodes)
    .filter(([leaf, comps]) => comps.length > 1)
    .map(([leaf, comps]) => ({
      pattern: leaf,
      components: comps,
      suggestion: 'Consider consolidating these components',
    }))
}

Shared Class Usage Alert

// Alert if class is used by multiple components
function checkSharedClasses(components, exclusionList = []) {
  const classUsage = {}
  components.forEach((comp) => {
    comp.imports.forEach((imp) => {
      if (!exclusionList.includes(imp)) {
        if (!classUsage[imp]) classUsage[imp] = []
        classUsage[imp].push(comp.name)
      }
    })
  })

  return Object.entries(classUsage)
    .filter(([cls, users]) => users.length > 1)
    .map(([cls, users]) => ({
      class: cls,
      usedBy: users,
      suggestion: 'Consider extracting to shared component or library',
    }))
}

Imported: Common Patterns to Look For

High Consolidation Candidates

• Notification:

  *.notification

  ,

  *.notify

  ,

  *.email

• Audit:

  *.audit

  ,

  *.auditing

  ,

  *.log

• Validation:

  *.validation

  ,

  *.validate

  ,

  *.validator

• Formatting:

  *.format

  ,

  *.formatter

  ,

  *.formatting

• Reporting:

  *.report

  ,

  *.reporting

  (if similar functionality)

Low Consolidation Candidates

• Infrastructure:

  *.util

  ,

  *.helper

  ,

  *.common

  (usually infrastructure)
• Different contexts: Same name, different business meaning
• High coupling risk: Consolidation would create bottleneck

Imported: Notes

• Common domain functionality is different from infrastructure functionality
• Consolidation reduces duplication but may increase coupling
• Always analyze coupling impact before consolidating
• Shared services vs shared libraries have different trade-offs
• Some duplication is acceptable if it reduces coupling
• Not all common patterns should be consolidated