XCTestCaseExtentensionsSnippet.swift

// MARK: - Expectations
extension XCTestCase {
    
    enum Expectation: String {
        case Exists = "exists == 1"
        case NotExists = "exists == 0"
        case Hittable = "hittable == 1"
        case NotHittable = "hittable == 0"
        
        func predicate() -> NSPredicate {
            return NSPredicate(format: self.rawValue, argumentArray: nil)
        }
    }
    
    /**
     Short hand version to check if an element exists. Returns the check object.
     
     - parameter expectation:   An expectation which should match
     - parameter object:        Object to perform check on
     - parameter timeout:       How long we query until timeout
     - parameter expectHandler: called if expectation matches
     - parameter waitHandler:   called if waiting is completed
     
     - returns: Original object passed as object to to check
     */
    func expect<T: AnyObject>(_ expectation: Expectation, object: T, timeout: TimeInterval, expectHandler: XCPredicateExpectationHandler? = nil, waitHandler: XCWaitCompletionHandler? = nil) -> T {
        self.expectation(for: expectation.predicate(), evaluatedWith: object, handler: expectHandler)
        self.waitForExpectations(timeout: timeout, handler: waitHandler)
        
        return object
    }
}