Make key string optional.

This PR allows us to define the key in a more comfortable way:

extension DefaultsKeys {
    // Before
    var username: DefaultsKey<String?> { .init("username") }

    // After
    var username: DefaultsKey<String?> { .init() }
}

I am not sure about the best way to add test cases to the existing system. Instead, I run this test locally.


import XCTest
@testable import SwiftyUserDefaults

extension DefaultsKeys {
    var username: DefaultsKey<String?> { .init() }
    var launchCount: DefaultsKey<Int> { .init(defaultValue: 0) }
    var hotkeyEnabled: DefaultsKey<Bool> { .init("hotkey", defaultValue: true) }
}

class MyTest: XCTestCase {

    func testKeys() {
        let ud = UserDefaults.standard

        Defaults.username = nil
        XCTAssertNil(ud.string(forKey: "username"))
        Defaults.username = "foo"
        XCTAssertEqual("foo", ud.string(forKey: "username"))

        Defaults.launchCount = 20
        XCTAssertEqual(20, ud.integer(forKey: "launchCount"))
        Defaults.removeAll()
        XCTAssertEqual(0, ud.integer(forKey: "launchCount"))

        XCTAssertTrue(Defaults.hotkeyEnabled)
        Defaults.hotkeyEnabled = false
        XCTAssertEqual(NSNumber(value: false), ud.object(forKey: "hotkey") as? NSNumber)
    }
}

sunshinejr / SwiftyUserDefaults

Make key string optional. #256