cjnevin

struct User {
  struct Prefs {
    let email: Bool, sms: Bool
  }
  let name: String, prefs: Prefs
}
let user = User(name: "Test", prefs: Prefs(email: true, sms: false))

// Previously:
assert(user.name.isEmpty) == true

cjnevin

@dynamicMemberLookup
struct Assert<T> {
    let value: T

    subscript<Value>(dynamicMember keyPath: KeyPath<T, Value>) -> Assert<Value> {
        .init(value: value[keyPath: keyPath])
    }
}

func assert<T>(_ root: T, _ closure: (Assert<T>) throws -> Void) rethrows {

cjnevin

func == <T: Equatable>(lhs: Assert<T>, rhs: T) {
    lhs.equal(to: rhs)
}

// usage:
assert(actual) == expected

cjnevin

let actual = "Test"
let expected = "Test"
assert(actual).equal(to: expected)

cjnevin

extension Assert where T: Equatable {
    func equal(to other: T, file: StaticString = #file, line: UInt = #line) {
        XCTAssertEqual(value, other, file: file, line: line)
    }
}

cjnevin

struct Assert<T> {
    let value: T
}

func assert<T>(_ value: @autoclosure () throws -> T) rethrows -> Assert<T> {
    try .init(value: value())
}

cjnevin

import XCTest

@resultBuilder
struct AssertionBuilder {
    static func buildArray(_ components: [Bool]) -> Bool {
        components.reduce(true) { $0 && $1 }
    }

    static func buildBlock(_ components: Bool...) -> Bool {
        components.reduce(true) { $0 && $1 }

cjnevin

protocol Resolver {
    func resolve<T>(_ type: T.Type) -> T
}

class MainResolver: Resolver {
    static let shared = MainResolver()

    private var dependencies: [Any] = []

cjnevin

addSubview(redView) {
  $0.edges(20).equalToSuperview()
  $0.addSubview(greenView) {
    $0.edges(30).equalToSuperview()
  }
}

cjnevin

addSubview(redView) {
   $0.edges(20).equalToSuperview()
}