WeakSet Tests

import XCTest

final class WeakSetTests: XCTestCase {

    var subject: WeakSet<ThemeObserver>!

    override func setUp() {
        subject = []
    }

    override func tearDown() {
        subject = nil
    }

    func test_initLiteral_oneObject_subjectHasOneObject() {
        let view = MockThemedView()
        subject = [view]
        XCTAssertEqual(subject.count, 1)
    }

    func test_initLiteral_oneObject_addSameObjectTwoTimes_subjectHasOneObject() {
        let view = MockThemedView()
        subject = [view, view]
        XCTAssertEqual(subject.count, 1)
    }

    func test_initLiteral_oneObject_objectIsNil_subjectDoesntHoldObject_objectIsNil() {
        var view: MockThemedView? = MockThemedView()
        weak var weakView: MockThemedView? = view
        subject = [view!]
        view = nil
        XCTAssertNil(weakView)
    }

    func test_initLiteral_oneObject_objectIsNil_accessViewFromSet_subjectDoesntHoldObject_obejctIsNil() {
        var view: MockThemedView? = MockThemedView()
        subject = [view!]
        view = nil
        XCTAssertNil(subject.allObjects.first)
    }

    func test_initLiteral_threeHundertFour_objectsAreNil_subjectDoesntHoldObjects_objectsAreNil() {
        var mockViews: [MockThemedView]? = threeHundertFourViews()
        subject = WeakSet(mockViews!)
        mockViews = nil
        XCTAssertNil(mockViews)
    }

    private func threeHundertFourViews() -> [MockThemedView] {
        var views = [MockThemedView]()
        for _ in 1 ... 304 {
            views.append(MockThemedView())
        }
        return views
    }
}