tieleman

class FakeAuthorService: AuthorServiceProtocol {
    func fetchAllAuthors() -> [Author] {
        [
            Author(firstName: "Frank", lastName: "Herbert", booksWritten: 27),
            Author(firstName: "Roald", lastName: "Dahl", booksWritten: 19),
            Author(firstName: "Haruki", lastName: "Marukami", booksWritten: 14)
        ]
    }
}

tieleman

protocol AuthorServiceProtocol {
    func fetchAllAuthors() -> [Author]
}

class AuthorWebService: AuthorServiceProtocol {
    func fetchAllAuthors() -> [Author] {
        // fetch and return authors
    }
}

tieleman

struct Author {
    var firstName: String
    var lastName: String
    var booksWritten: Int
}

class AuthorViewModel {
    private let service = AuthorWebService()
    
    func allAuthors() -> [Author] {

tieleman

// Put in top level file scope
extension View {
    func eraseToAnyView() -> AnyView {
        AnyView(self)
    }
}

private func buildComplexButton() -> some View {
    if someConditional {
        return Button(action: { /* do something */ }) {

tieleman

private func buildComplexButton() -> some View {
    if someConditional {
        return AnyView(Button(action: { /* do something */ }) {
            Text("1")
        })
    } else {
        return AnyView(Button(action: { /* do something else */ }) {
            Image(systemName: "faceid")
        })
    }

tieleman

private func buildComplexButton() -> some View {
    Group {
        if someConditional {
            Button(action: { /* do something */ }) {
                Text("1")
            }
        } else {
            Button(action: { /* do something else */ }) {
                Image(systemName: "faceid")
            }

tieleman

private func buildComplexButton() -> some View {
    if someConditional {
        return Button(action: { /* do something */ }) {
            Text("1")
        }
    } else {
        return Button(action: { /* do something else */ }) {
            Image(systemName: "faceid")
        }
    }

tieleman

private func buildComplexButton() -> some View {
    if someConditional {
        return Button("Press me") {
            // do something
        }
    } else {
        return Button("No, press me") {
            // do something else
        }
    }

tieleman

import Accelerate
import XCTest

let array = Array(stride(from: 0.0, to: 50000.0, by: 1))
let array2 = Array(stride(from: 0.0, to: 50000.0, by: 1))
let array3 = Array(stride(from: 0.0, to: 50000.0, by: 1))

class MathTests: XCTestCase {
    func testMeanSwifty() {
        measure {

tieleman

func multiply(_ array: [Double]) -> [Double] {
    // Allocate memory for the output array
    let output = UnsafeMutablePointer<Double>.allocate(capacity: array.count)
    
    // Make sure we free up the memory once we're done
    defer {
        output.deinitialize(count: array.count)
        output.deallocate()
    }