Merge pull request malcommac#78 from malcommac/bug/77-fix-chainable-t…

…hens-xcode12

[malcommac#77] [Bug] Fixed chainable thens operators in Xcode 12/Swift 5.3

Sources/Hydra/Promise+Cancel.swift

@@ -41,7 +41,7 @@ public extension Promise {
 	///   - body: body to execute
 	/// - Returns: a new void promise
 	@discardableResult
-	func cancelled(in context: Context? = nil, _ body: @escaping (() -> (()))) -> Promise<Void> {
+	func cancelled(in context: Context? = nil, _ body: @escaping (() -> (Void))) -> Promise<Void> {
 		let ctx = context ?? .main
 		let nextPromise = Promise<Void>(in: ctx, token: self.invalidationToken) { resolve, reject, operation in
 			let onResolve = Observer.onResolve(ctx, { _ in

Tests/HydraTests/HydraTests.swift

@@ -356,6 +356,23 @@ class HydraTestThen: XCTestCase {
 		}
 		waitForExpectations(timeout: expTimeout, handler: nil)
 	}
+
+    func test_thenChainAndAlways() {
+        let exp = expectation(description: "test_anyWithArray")
+        var passedThens = 0
+
+        Promise<Int>(in: .background, token: nil) { (r, rj, s) in
+            r(10)
+        }.then { _ in
+            passedThens += 1
+        }.always(in: .main) {
+            passedThens += 1
+            XCTAssertTrue(passedThens == 2, "Not all thens are passed")
+            XCTAssertTrue(Thread.isMainThread, "Failed, the operation is not on main thread as we expect")
+            exp.fulfill()
+        }
+        waitForExpectations(timeout: expTimeout, handler: nil)
+    }
 
 	/// The same test with `any` operator which takes as input an array instead of variable list of arguments
 	func test_anyWithArray() {