Swift:
Refactoring
How to:
Let’s start with a basic Swift example where we have some repetitive code:
func printUserDetails(firstName: String, lastName: String, age: Int) {
print("First Name: \(firstName)")
print("Last Name: \(lastName)")
print("Age: \(age)")
}
func printUserJob(title: String, company: String) {
print("Job Title: \(title)")
print("Company: \(company)")
}Refactoring this would include creating a User struct to encapsulate user attributes and add a method to print details:
struct User {
let firstName: String
let lastName: String
let age: Int
let jobTitle: String
let company: String
func printDetails() {
print("First Name: \(firstName)")
print("Last Name: \(lastName)")
print("Age: \(age)")
print("Job Title: \(jobTitle)")
print("Company: \(company)")
}
}
let user = User(firstName: "John", lastName: "Doe", age: 30, jobTitle: "Software Developer", company: "Tech Solutions")
user.printDetails()Sample Output:
First Name: John
Last Name: Doe
Age: 30
Job Title: Software Developer
Company: Tech SolutionsDeep Dive
Refactoring has roots that go back to the early days of software engineering, but the term was popularized in the late 1990s, particularly through Martin Fowler’s seminal book “Refactoring: Improving the Design of Existing Code”. The book laid out the principle that code should be continuously cleaned up in small steps rather than waiting for a separate phase.
Alternatives to manual refactoring include automated tools and IDEs (Integrated Development Environments) that can help detect duplicate code, suggest simplifications, and auto-generate portions of code. Xcode, for Swift development, offers various refactoring tools, such as rename and extract method functionality, that can reduce the potential for human error in the process.
When implementing refactoring, it’s important to have a solid test suite in place. Tests act as a safety net, ensuring that the changes you’re making aren’t introducing bugs. This is vital since the main goal of refactoring is to alter the internal structure without affecting external behavior.