Fulfiller+Example.swift

extension XCTestExpectation {
    var fulfiller: DeinitBlock {
        return DeinitBlock {
            print("Fulfill \(self.description)")
            self.fulfill()
        }
    }
}

class FillfilerTests: XCTestCase {
    func testFulfillWithDispatchQueue() {
        let queue = DispatchQueue(label: #function)
        (0..<10).forEach { index in
            let fulfiller = expectation(description: "\(#function) \(index)").fulfiller
            if index.isMultiple(of: 2) {
                // automatically fulfilled on exiting scope
                return
            }
            queue.async {
                // fullfiled when closure is released
                print("Retaining: \(fulfiller)")
            }
        }
        waitForExpectations(timeout: 1, handler: nil)
    }
}