NSNotificationCentre Unit test cases

UnitTesting.playground

class PointsOfInterestTableViewControllerTests: XCTestCase {
    func testNotification() {
        let notificationCenter = NotificationCenter()
        let observer = PointsOfInterestTableViewController(notificationCenter:
            notificationCenter)
        XCTAssertFalse(observer.didHandleNotification)
        //       Notification posted to just this center, isolating the test
        let name = CurrentLocationProvider.authChangedNotification
        notificationCenter.post(name: name, object: nil)
        XCTAssertTrue(observer.didHandleNotification)
    }
}
PointsOfInterestTableViewControllerTests.defaultTestSuite.run()

class CurrentLocationProviderTests: XCTestCase {
    func testNotifyAuthChanged() {
        let notificationCenter = NotificationCenter()
        let poster = CurrentLocationProvider(notificationCenter: notificationCenter)
        // Notification only sent to this specific center, isolating test
        let name = CurrentLocationProvider.authChangedNotification
        let expectation = XCTNSNotificationExpectation(name: name, object: poster,
                                                       notificationCenter: notificationCenter)
        poster.notifyAuthChanged()
        wait(for: [expectation], timeout: 0)
    }
}