marioiannotta / swizzleswift

Swizzle selectors with just one clean and elegant API

Hey there!

I'm just a guy who loves to code and has been doing it since I was 13. I wore many hats (EM, tech lead, IC, rubber duck) and experimented with different technologies but in the past years I've been focusing mostly on iOS.

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swizzleswift's Issues

SwizzleFunctionBuilder returns SwizzlePair when arguments passed only one SwizzlePair

In SwizzleSwiftDemo, Xcode cannot build the following code because of an error Cannot convert value of type 'SwizzlePair' to closure result type '[SwizzlePair]'.

Swizzle(ViewController.self) {
    #selector(viewDidLoad) ==> #selector(myViewDidLoad)
}

Passing an array of SwizzlePair instead of @_functionBuilder may resolve this issue.

Swizzle(ViewController.self, [
    #selector(viewDidLoad) ==> #selector(myViewDidLoad),
    #selector(viewWillAppear(_:)) ==> #selector(myViewWillAppear(_:)),
])

Can only swizzle functions with @objc keyword

I tried to write a swizzle demo:

• First, I defined a class which is called MyClass with some functions;
• Then, I defined another class which is called MyClassHook. In this class with another set of functions;
• I used functions of MyClassHook to swizzle MyClass.

BUT! The compiler says I must add @objc keyword at the functions of MyClass. But I don’t want to do that.

Is there a way that I can avoid this issue?

Swift Package Manager issues

I can't get this repo to work with SPM.

I get the following error:

The remote repository could not be accessed. Make sure a valid repository exists at the specified location and that the correct credentials have been supplied.

Even when I tried to fork it and update the versioning to semver.

Always return nil when swizzling

I wrote the code:

class MyClass {
    @objc func origA() {
        print(#function)
    }
    @objc func origB(_ arg1: Bool) {
        print(#function)
    }
}
class MyClassHook {
    @objc func myA() {
        print(#function)
    }
    @objc func myB(_ arg1: Bool) {
        print(#function)
    }
}
MyClass().origA() // prints: origA()
MyClass().origB() // prints: origB()

Swizzle(MyClass.self) {
    #selector(MyClass.origA) <-> #selector(MyClassHook.myA)
    #selector(MyClass.origB(_:)) <-> #selector(MyClassHook.myB(_:))
}

MyClass().origA() // prints: origA(), expected: myA()

MyClass().origB() // prints: origB(), expected: myB()

I swizzle the method in right way. After swizzle, I print origA() and origB(), I expected them to be myA() and myB(), but the console still print origA() and origB().

I run in debug mode and found that, in SwizzleSwift.swift, public struct Swizzle, there’ s a code;

guard
                let original = class_getInstanceMethod(type, SwizzlePair.original),
                let swizzled = class_getInstanceMethod(type, SwizzlePair.swizzled)
            else { return }

And this code always execute the else block, which means that original or swizzled is returning nil.

Why? Is there a problem in my code?