Feature verification

Feature Verification Skill

Purpose

Systematic cross-platform feature verification to prevent false differentiation and ensure accurate feature matrices. This skill provides protocols for verifying that features claimed as "missing" aren't simply named differently.

Activation

This skill is critical during:

• Phase 3: Feature Matrix Development
• Phase 7: Architecture Analysis
• Phase 8: Requirements Alignment
• Any phase comparing capabilities across candidates

Core Verification Protocol

Step 1: Terminology Mapping

Before claiming a feature is missing, check for equivalent terminology:

## Common Terminology Variations

| Concept | Framework A | Framework B | Framework C |
|---------|-------------|-------------|-------------|
| Request Pipeline | Middleware | Interceptors | Plugins |
| Dependency Injection | DI Container | Services | Providers |
| Data Validation | Validators | Schema | Serializers |
| Background Jobs | Workers | Tasks | Jobs |
| Real-time | WebSocket | Channels | Hubs |
| Caching | Cache | Store | Repository |
| Authentication | Auth | Identity | Security |
| API Documentation | OpenAPI | Swagger | API Docs |
| Testing | Test Client | Test Utils | Testing Module |
| CLI Tools | CLI | Artisan | Management Commands |

Step 2: Architectural Equivalence

Same outcome achieved through different architectural patterns:

## Pattern-Based Equivalence

### Built-in vs. Convention-Based
| Requirement | Explicit Support | Convention Approach |
|-------------|------------------|---------------------|
| Auto-validation | Decorator-based | File naming convention |
| Route generation | Explicit decorators | Directory structure |
| Dependency injection | Container | Module imports |

### Framework vs. Ecosystem
| Requirement | In Framework | In Ecosystem |
|-------------|--------------|--------------|
| ORM | Built-in ORM | Official adapter for X |
| Authentication | Auth module | Official strategy Y |
| Caching | Cache layer | Redis/Memcached adapter |

Step 3: Search Protocol

For each "missing" feature, execute this search sequence:

## Feature Verification Search Sequence

### 1. Official Documentation
- Search: `site:<docs-url> "<feature-name>"`
- Search: `site:<docs-url> "<alternative-term>"`
- Check: API reference, guides, tutorials

### 2. Repository Search
- Search: `<feature> repo:<org>/<repo>`
- Check: README, source code, examples
- Look for: interfaces, abstract classes, extension points

### 3. GitHub Issues/Discussions
- Search: `is:issue "<feature>" repo:<org>/<repo>`
- Look for: Feature requests (indicates missing)
- Look for: Closed with "already exists" or "use X instead"

### 4. Community Resources
- Search: `"<framework>" "<feature>" tutorial`
- Check: Blog posts, Stack Overflow, Reddit
- Look for: Community implementations, plugins

### 5. Package Registries
- npm: `<framework> <feature>`
- PyPI: `<framework>-<feature>`
- Check: Official vs. community packages

Step 4: Verification Documentation

Document verification results in standard format:

## Feature Verification Record

### Feature: <feature-name>

**Search Date**: <date>
**Candidate**: <framework-name>
**Initial Status**: Missing

**Verification Steps**:
1. ✅ Official docs - Not found
2. ✅ Repo search - Found in `<file>` as `<alternate-name>`
3. ❌ Issue search - Skipped (found in step 2)
4. ❌ Community - Skipped

**Result**: EXISTS as `<alternate-name>`
**Evidence**: [Link to documentation/code]
**Notes**: <any important context>

**Final Status**: ✅ Available (as <alternate-name>)

Cross-Platform Feature Matrix Template

Use this template to ensure thorough verification:

## Feature Comparison: <Feature Category>

| Feature | <Framework A> | <Framework B> | <Framework C> | Verified |
|---------|---------------|---------------|---------------|----------|
| <name> | ✅ `name_a` | ✅ `name_b` [^1] | ❌ Verified | 2025-01-16 |
| <name> | ✅ [OSS] | ⚠️ [PLUGIN] req | ✅ [OSS] | 2025-01-16 |
| <name> | ❌ Verified | ✅ [OSS] | ✅ [PAID] | 2025-01-16 |

[^1]: Called "alternative-name" in Framework B documentation

Equivalence Categories

Direct Equivalent

Same feature, different name:

| Framework A | Framework B | Type |
|-------------|-------------|------|
| `middleware()` | `interceptor()` | Direct equivalent |

Functional Equivalent

Different approach, same outcome:

| Framework A | Framework B | Type |
|-------------|-------------|------|
| Decorator-based routing | Convention-based routing | Functional equivalent |

Partial Equivalent

Similar but with differences:

| Framework A | Framework B | Type |
|-------------|-------------|------|
| Full DI container | Manual DI support | Partial - A has more features |

Ecosystem Equivalent

Available via official plugin/extension:

| Framework A | Framework B | Type |
|-------------|-------------|------|
| Built-in ORM | Official ORM adapter | Ecosystem - same outcome |

Not Equivalent

Genuinely missing:

| Framework A | Framework B | Type |
|-------------|-------------|------|
| GraphQL subscriptions | No equivalent found | Not equivalent - verified missing |

Red Flags Requiring Verification

Always verify when:

1. Popular framework "missing" common feature - Likely terminology difference
2. Feature exists in similar frameworks - Check for equivalent pattern
3. Feature is table stakes for category - Probably exists somehow
4. Documentation seems incomplete - Check code and community
5. Framework newer than feature concept - May use different approach

Verification Checklist

Before marking any feature as ❌:

## Feature Missing Verification

Feature: <name>
Candidate: <framework>

- [ ] Searched official docs with 3+ terms
- [ ] Searched repository code
- [ ] Checked GitHub issues for "already exists" responses
- [ ] Searched for community plugins/packages
- [ ] Verified no architectural equivalent exists
- [ ] Documented all search attempts

If all checked, feature can be marked as ❌ Missing
Otherwise, continue investigation

Common False Differentiations

These features almost always exist in some form:

Feature	Why It Almost Always Exists	What to Search For
Logging	Basic infrastructure	logger, logging, log
Configuration	Basic infrastructure	config, settings, env
Testing	Development essential	test, testing, spec
Validation	Common requirement	validate, schema, serializer
Caching	Performance basic	cache, store, memoize
Authentication	Security basic	auth, session, identity
Error Handling	Infrastructure	exception, error, handler
CLI	Developer productivity	cli, command, manage

Integration with Bias Prevention

This skill directly addresses:

• Pitfall 2: False Feature Differentiation
• Pitfall 6: Marketing Language (by verifying claims)
• Pitfall 9: Confirmation Bias (systematic search counters cherry-picking)