Use XCTestExpectation instead of counter (#18)

Author: davdroman

Tests/AtomicTransitionTests/AsymmetricTests.swift

@@ -7,36 +7,34 @@ final class AsymmetricTests: XCTestCase {
     let contextUsed = UnimplementedUIKitContext()
 
     func testInsertion() {
-        var handlerCalls = 0
+        let expectation = expectation(description: "Handler called")
         let sut = AtomicTransition.asymmetric(
             insertion: .spy { [self] animator, view, operation, context in
                 XCTAssertIdentical(animator, animatorUsed)
                 XCTAssertIdentical(view, viewUsed)
                 XCTAssertEqual(operation, .insertion)
                 XCTAssertIdentical(context, contextUsed)
-                handlerCalls += 1
+                expectation.fulfill()
             },
             removal: .spy { XCTFail() }
         )
-        XCTAssertEqual(handlerCalls, 0)
         sut.prepare(animatorUsed, or: viewUsed, for: .insertion, in: contextUsed)
-        XCTAssertEqual(handlerCalls, 1)
+        wait(for: [expectation], timeout: 0)
     }
 
     func testRemoval() {
-        var handlerCalls = 0
+        let expectation = expectation(description: "Handler called")
         let sut = AtomicTransition.asymmetric(
             insertion: .spy { XCTFail() },
             removal: .spy { [self] animator, view, operation, context in
                 XCTAssertIdentical(animator, animatorUsed)
                 XCTAssertIdentical(view, viewUsed)
                 XCTAssertEqual(operation, .removal)
                 XCTAssertIdentical(context, contextUsed)
-                handlerCalls += 1
+                expectation.fulfill()
             }
         )
-        XCTAssertEqual(handlerCalls, 0)
         sut.prepare(animatorUsed, or: viewUsed, for: .removal, in: contextUsed)
-        XCTAssertEqual(handlerCalls, 1)
+        wait(for: [expectation], timeout: 0)
     }
 }

Tests/AtomicTransitionTests/AtomicTransitionTests.swift

@@ -8,17 +8,16 @@ final class AtomicTransitionTests: XCTestCase {
         let operationUsed = AtomicTransition.Operation.random()
         let contextUsed = UnimplementedUIKitContext()
 
-        var handlerCalls = 0
+        let expectation = expectation(description: "Handler called")
         let sut = AtomicTransition.spy { animator, view, operation, context in
             XCTAssertIdentical(animator, animatorUsed)
             XCTAssertIdentical(view, viewUsed)
             XCTAssertEqual(operation, operationUsed)
             XCTAssertIdentical(context, contextUsed)
-            handlerCalls += 1
+            expectation.fulfill()
         }
 
-        XCTAssertEqual(handlerCalls, 0)
         sut.prepare(animatorUsed, or: viewUsed, for: operationUsed, in: contextUsed)
-        XCTAssertEqual(handlerCalls, 1)
+        wait(for: [expectation], timeout: 0)
     }
 }

Tests/AtomicTransitionTests/CustomTests.swift

@@ -10,17 +10,16 @@ final class CustomTests: XCTestCase {
         let operationUsed = AtomicTransition.Operation.random()
         let contextUsed = UnimplementedUIKitContext()
 
-        var handlerCalls = 0
+        let expectation = expectation(description: "Handler called")
         let sut = AtomicTransition.custom(withAnimator: { animator, uiView, operation, context in
             XCTAssertIdentical(animator, animatorUsed)
             XCTAssertIdentical(uiView, uiViewUsed)
             XCTAssertEqual(operation, operationUsed)
             XCTAssertIdentical(context, contextUsed)
-            handlerCalls += 1
+            expectation.fulfill()
         })
-        XCTAssertEqual(handlerCalls, 0)
         sut.prepare(animatorUsed, or: viewUsed, for: operationUsed, in: contextUsed)
-        XCTAssertEqual(handlerCalls, 1)
+        wait(for: [expectation], timeout: 0)
     }
 
     func testWithTransientView() {
@@ -30,15 +29,14 @@ final class CustomTests: XCTestCase {
         let containerViewUsed = UIView()
         let contextUsed = MockedUIKitContext(containerView: containerViewUsed)
 
-        var handlerCalls = 0
+        let expectation = expectation(description: "Handler called")
         let sut = AtomicTransition.custom(withTransientView: { view, operation, container in
             XCTAssertIdentical(view, viewUsed)
             XCTAssertEqual(operation, operationUsed)
             XCTAssertIdentical(container, containerViewUsed)
-            handlerCalls += 1
+            expectation.fulfill()
         })
-        XCTAssertEqual(handlerCalls, 0)
         sut.prepare(animatorUsed, or: viewUsed, for: operationUsed, in: contextUsed)
-        XCTAssertEqual(handlerCalls, 1)
+        wait(for: [expectation], timeout: 0)
     }
 }