Code Smells Detector

Overview

This skill analyzes PHP codebases for code smells (symptoms of deeper problems) and generates detailed reports with severity levels and refactoring recommendations.

Code Smells Catalog

Smell	Description	Detection	Severity
God Class	Class doing too much	>500 LOC, >15 methods	CRITICAL
Feature Envy	Method uses another class more	Foreign calls > own calls	WARNING
Data Clumps	Same fields appear together	3+ repeated params/fields	WARNING
Long Parameter List	Method with many params	>4 parameters	WARNING
Long Method	Method doing too much	>50 LOC	WARNING
Primitive Obsession	Primitives instead of objects	string $email, int $money	INFO
Message Chains	Long getter chains	->get()->get()->get()	WARNING
Inappropriate Intimacy	Classes knowing too much	Direct field access	WARNING

Detection Patterns

God Class Detection

bash

# Large classes (>500 lines)
Grep: "^class " --glob "**/*.php"
# Then check file line counts

# Many public methods (>15)
Grep: "public function " --glob "**/*.php"
# Count per file

# Many dependencies (>8)
Grep: "__construct" --glob "**/*.php" -A 20
# Count constructor parameters

# Problematic names
Grep: "class.*Manager|class.*Handler|class.*Helper|class.*Util|class.*Processor" --glob "**/*.php"

Indicators:

Class > 500 lines → CRITICAL
Class > 15 public methods → CRITICAL
Class > 8 constructor dependencies → WARNING
Class name contains Manager, Handler, Helper, Util → INFO

Feature Envy Detection

bash

# Methods using other class data excessively
Grep: "\$this->[a-z]+->get[A-Z]" --glob "**/*.php"

# Multiple calls to same foreign object
Grep: "\$[a-z]+->.*\$[a-z]+->" --glob "**/*.php"

# Getters called more than own methods
Grep: "function [a-z]+\(" --glob "**/*.php" -A 30
# Analyze method bodies for foreign vs own calls

Indicators:

Method calls other object's methods > own methods → WARNING
Multiple chained calls to foreign object → INFO
Method only transforms data from another class → WARNING

Data Clumps Detection

bash

# Repeated parameter groups in constructors
Grep: "__construct\(" --glob "**/*.php" -A 10
# Look for patterns: (string $x, string $y, string $z) appearing multiple times

# Repeated parameter groups in methods
Grep: "function [a-z]+\(" --glob "**/*.php"
# Look for same 3+ parameter combinations

# Multiple classes with same field groups
Grep: "(private|readonly) (string|int|float)" --glob "**/*.php"
# Detect repeated field patterns

Common Data Clumps:

```
$street, $city, $zipCode, $country
```
→ Address Value Object
```
$startDate, $endDate
```
→ DateRange Value Object
```
$amount, $currency
```
→ Money Value Object
```
$firstName, $lastName, $email
```
→ Contact/Person Value Object

Long Parameter List Detection

bash

# Methods with many parameters
Grep: "function [a-z]+\(" --glob "**/*.php"
# Count parameters (comma-separated)

# Constructors with many parameters
Grep: "__construct\(" --glob "**/*.php" -A 15
# Count parameters

Thresholds:

4+ parameters → INFO
6+ parameters → WARNING
8+ parameters → CRITICAL

Long Method Detection

bash

# Find method definitions and count lines until closing brace
Grep: "function [a-z]+\(" --glob "**/*.php" -A 60
# Analyze method length

# Nested control structures (indicator of complexity)
Grep: "if\s*\(.*\{.*if\s*\(" --glob "**/*.php" --multiline

Thresholds:

30+ lines → INFO
50+ lines → WARNING
100+ lines → CRITICAL

Primitive Obsession Detection

bash

# String parameters that should be Value Objects
Grep: "string \$email|string \$phone|string \$url|string \$currency|string \$country" --glob "**/*.php"

# Integer amounts
Grep: "int \$amount|int \$price|int \$total|int \$money|int \$cents" --glob "**/*.php"

# Float for money
Grep: "float \$amount|float \$price|float \$money" --glob "**/*.php"

# String status/type
Grep: "string \$status|string \$type|string \$state" --glob "**/*.php"

# Magic strings
Grep: "=== 'pending'|=== 'active'|=== 'completed'|=== 'draft'" --glob "**/*.php"

Should be Value Objects:

Email addresses → Email
Phone numbers → PhoneNumber
URLs → Url or Uri
Money amounts → Money (with currency)
Dates/periods → DateRange, Period
Identifiers → UserId, OrderId, etc.
Status/Type → Enum

Message Chains Detection

bash

# Long getter chains
Grep: "->get[A-Z][a-z]+\(\)->get[A-Z][a-z]+\(\)" --glob "**/*.php"

# Triple or more chains
Grep: "->.*->.*->" --glob "**/*.php"

# Law of Demeter violations
Grep: "\$this->[a-z]+->get[A-Z].*->get[A-Z]" --glob "**/*.php"

Indicators:

2 chained getters → INFO
3+ chained getters → WARNING
Chains in loops → CRITICAL

Inappropriate Intimacy Detection

bash

# Direct public property access
Grep: "\$[a-z]+->(?!get|set|is|has|can)[a-z]+" --glob "**/*.php"

# Friend classes accessing private state (via reflection)
Grep: "ReflectionClass|ReflectionProperty|setAccessible" --glob "**/*.php"

# Classes knowing internal structure
Grep: "->getInternalState|->getRawData|->getFields" --glob "**/*.php"

Report Format

markdown

# Code Smells Analysis Report

## Summary

| Smell | Critical | Warning | Info |
|-------|----------|---------|------|
| God Class | X | X | - |
| Feature Envy | - | X | X |
| Data Clumps | - | X | - |
| Long Parameter List | X | X | X |
| Long Method | - | X | X |
| Primitive Obsession | - | X | X |
| Message Chains | - | X | X |
| Inappropriate Intimacy | - | X | - |

**Total Issues:** X critical, X warnings, X info

## Critical Issues

### SMELL-001: God Class
- **File:** `src/Service/OrderManager.php`
- **Lines:** 847
- **Public Methods:** 23
- **Dependencies:** 12
- **Issue:** Class has too many responsibilities
- **Refactoring:**
  - Extract `OrderValidator` (validation logic)
  - Extract `OrderNotifier` (notification logic)
  - Extract `OrderPriceCalculator` (pricing logic)
- **Skills:** `create-use-case`, `create-domain-service`

### SMELL-002: Long Parameter List
- **File:** `src/Domain/Order/Order.php:45`
- **Method:** `createOrder()`
- **Parameters:** 9
- **Issue:** Too many parameters, hard to maintain
- **Refactoring:** Introduce Parameter Object
- **Skills:** `create-dto`, `create-builder`

## Warning Issues

### SMELL-003: Data Clump
- **Files:**
  - `src/Domain/User/User.php:15` — $street, $city, $zipCode
  - `src/Domain/Company/Company.php:23` — $street, $city, $zipCode
  - `src/Application/DTO/CreateOrderDTO.php:8` — $street, $city, $zipCode
- **Issue:** Address fields repeated across 3 classes
- **Refactoring:** Extract Address Value Object
- **Skills:** `create-value-object`

### SMELL-004: Feature Envy
- **File:** `src/Service/ReportGenerator.php:89`
- **Method:** `generateUserReport()`
- **Issue:** Method makes 15 calls to User object, only 2 to own class
- **Refactoring:** Move method to User or create UserReportBuilder
- **Skills:** `create-domain-service`

### SMELL-005: Primitive Obsession
- **File:** `src/Domain/User/User.php:12`
- **Field:** `private string $email`
- **Issue:** Email should be Value Object for validation
- **Refactoring:** Create Email Value Object
- **Skills:** `create-value-object`

### SMELL-006: Message Chain
- **File:** `src/Application/Handler/CreateOrderHandler.php:34`
- **Code:** `$user->getCompany()->getAddress()->getCountry()`
- **Issue:** Law of Demeter violation, tight coupling
- **Refactoring:** Add shortcut method or delegate

## Info Issues

### SMELL-007: Long Method
- **File:** `src/Infrastructure/Repository/OrderRepository.php:78`
- **Method:** `findByComplexCriteria()`
- **Lines:** 45
- **Issue:** Method approaching complexity threshold
- **Refactoring:** Extract query builder or specification

## Refactoring Priority

1. **Immediate:** God Classes blocking testing
2. **High:** Data Clumps causing duplication
3. **Medium:** Long Parameter Lists
4. **Low:** Message Chains, minor smells

Remediation Skills

Smell	Recommended Skill	Approach
God Class	`create-use-case` , `create-domain-service`	Extract focused classes
Feature Envy	`create-domain-service`	Move method to data owner
Data Clumps	`create-value-object`	Extract Value Object
Long Parameter List	`create-dto` , `create-builder`	Introduce Parameter Object
Long Method	`create-use-case`	Extract methods
Primitive Obsession	`create-value-object`	Replace with Value Object
Message Chains	(refactoring)	Hide delegate, extract method
Inappropriate Intimacy	(refactoring)	Move method, extract class

Quick Analysis Commands

bash

# Full smell detection
echo "=== God Classes ===" && \
find . -name "*.php" -path "*/src/*" -exec wc -l {} \; | awk '$1 > 400' && \
echo "=== Long Parameter Lists ===" && \
grep -rn "function [a-z]*(" --include="*.php" src/ | grep -E "(\$[a-z]+,\s*){5,}" && \
echo "=== Primitive Obsession ===" && \
grep -rn "string \$email\|string \$phone\|int \$amount\|float \$price" --include="*.php" src/ && \
echo "=== Message Chains ===" && \
grep -rn "->get[A-Z].*->get[A-Z].*->get[A-Z]" --include="*.php" src/ && \
echo "=== Magic Strings ===" && \
grep -rn "=== '[a-z]*'\|== '[a-z]*'" --include="*.php" src/

Integration with Other Skills

This skill works alongside:

```
analyze-solid-violations
```
— SOLID violations overlap with some smells
```
structural-auditor
```
— architectural context for smells
```
ddd-auditor
```
— domain model quality assessment

References

Based on Martin Fowler's "Refactoring" catalog:

https://refactoring.guru/refactoring/smells
"Refactoring: Improving the Design of Existing Code" (Fowler)

When This Is Acceptable

DTOs — Data classes are NOT a code smell; they serve a clear data transfer purpose
Configuration classes — Classes with many constants/properties for configuration
Builder pattern — Method chaining in builders creates apparent "Feature Envy" but is by design

False Positive Indicators

Class has
```
DTO
```
,
```
Request
```
,
```
Response
```
,
```
Config
```
in its name
Class implements a Builder pattern with fluent API
"Long parameter list" is actually a constructor with proper dependency injection

detect-code-smells

NPX Install

Tags

SKILL.md Content

Code Smells Detector

Overview

Code Smells Catalog

Detection Patterns

God Class Detection

Feature Envy Detection

Data Clumps Detection

Long Parameter List Detection

Long Method Detection

Primitive Obsession Detection

Message Chains Detection

Inappropriate Intimacy Detection

Report Format

Remediation Skills

Quick Analysis Commands

Integration with Other Skills

References

When This Is Acceptable

False Positive Indicators