Refactoring Advisor
Quick Start
Plan refactoring based on identified issues:
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Identify the problem (code smell, complexity)
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Select appropriate refactoring pattern
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Create step-by-step plan
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Ensure tests exist
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Refactor incrementally
Instructions
Step 1: Assess Current State
Analyze the code:
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What is the problem? (long method, god class, etc.)
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What is the impact? (maintainability, testability)
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What is the risk? (how much code depends on it)
Step 2: Select Refactoring Strategy
Problem Strategy Risk
Long Method Extract Method Low
God Class Extract Class Medium
Duplicated Code Extract Method Low
Switch Statement Replace with Polymorphism High
Long Parameter List Introduce Parameter Object Medium
Step 3: Create Refactoring Plan
Template:
Refactoring: [Name]
Problem: [Description] Goal: [Desired outcome] Risk Level: [Low/Medium/High]
Prerequisites
- Tests exist and pass
- Code is committed
- Dependencies identified
Steps
- [First small change]
- [Run tests]
- [Next small change]
- [Run tests] ...
Validation
- All tests pass
- No functionality changed
- Code is cleaner
Step 4: Execute Incrementally
Golden Rule: Make the change easy, then make the easy change
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Make one small change
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Run tests
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Commit
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Repeat
Refactoring Examples
Extract Method
Before:
function printOwing(invoice) { let outstanding = 0;
console.log(""); console.log("**** Customer Owes ****"); console.log("");
for (const o of invoice.orders) { outstanding += o.amount; }
console.log(name: ${invoice.customer});
console.log(amount: ${outstanding});
}
Plan:
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Extract banner printing
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Run tests
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Extract outstanding calculation
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Run tests
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Extract details printing
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Run tests
After:
function printOwing(invoice) { printBanner(); const outstanding = calculateOutstanding(invoice); printDetails(invoice, outstanding); }
function printBanner() { console.log(""); console.log("**** Customer Owes ****"); console.log(""); }
function calculateOutstanding(invoice) { return invoice.orders.reduce((sum, o) => sum + o.amount, 0); }
function printDetails(invoice, outstanding) {
console.log(name: ${invoice.customer});
console.log(amount: ${outstanding});
}
Extract Class
Before:
class Person { name; officeAreaCode; officeNumber;
getTelephoneNumber() {
return (${this.officeAreaCode}) ${this.officeNumber};
}
}
Plan:
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Create TelephoneNumber class
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Move areaCode field
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Run tests
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Move number field
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Run tests
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Move getTelephoneNumber method
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Run tests
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Update Person to use TelephoneNumber
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Run tests
After:
class TelephoneNumber { areaCode; number;
toString() {
return (${this.areaCode}) ${this.number};
}
}
class Person { name; telephoneNumber;
getTelephoneNumber() { return this.telephoneNumber.toString(); } }
Safety Checklist
Before refactoring:
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Tests exist and pass
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Code is in version control
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You understand what the code does
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You have time to complete the refactoring
During refactoring:
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Make small changes
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Run tests after each change
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Commit working states
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Don't add features while refactoring
After refactoring:
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All tests pass
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Code review completed
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Documentation updated
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No functionality changed