Detect unused code – ruby script from (https://github.com/PaulTaykalo)

In this article we will explore another way to detect unused code, by using a ruby script from https://github.com/PaulTaykalo/swift-scripts.

We have already tried the periphery tool http://trikalabs.com/detect-unused-code-periphery/

And let’s follow the same steps as we did for periphery in order to compare them!

1. Let’s create a project and name it UnusedCodeTest.
2. Next let’s add an unused class in the target:
   Swift

   class UnusedClass { }

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   class UnusedClass {      }

3. Also we add an unused method, a used method and a used method with an unused parameter:
   Swift

   struct ContentView: View { var body: some View { VStack { Text("Hello, world!") .padding() } .onAppear(perform: { methodCalled() methodUnusedParameter(a: 3, b: 4) }) } func methodCalled() { } func methodUnCalled() { } func methodUnusedParameter(a: Int, b: Int) { _ = a * a } }

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   struct ContentView: View {     var body: some View {         VStack {             Text("Hello, world!")                 .padding()         }         .onAppear(perform: {             methodCalled()             methodUnusedParameter(a: 3, b: 4)         })     }          func methodCalled() {              }          func methodUnCalled() {              }          func methodUnusedParameter(a: Int, b: Int) {         _ = a * a     } }

   Now, 

• As first step let’s download the repo.
• Then lest copy the usused.rb file inside our project folder.
• Then let’s run ./unused.rb

And here are our results:

It finds all the issues we found with periphery but it also inform us about the previews, which we want actually to keep them.

Overall, another great tool!