3.1 Added asObservable examples

Froussios · Froussios · commit 668ec62c0159 · 2015-05-25T21:20:48.000+02:00
diff --git a/tests/java/itrx/chapter3/sideeffects/AsObservableTest.java b/tests/java/itrx/chapter3/sideeffects/AsObservableTest.java
@@ -0,0 +1,176 @@
+package itrx.chapter3.sideeffects;
+
+import static org.junit.Assert.*;
+
+import java.util.Arrays;
+
+import org.junit.Test;
+
+import rx.Observable;
+import rx.observers.TestSubscriber;
+import rx.subjects.BehaviorSubject;
+import rx.subjects.Subject;
+
+public class AsObservableTest {
+
+	public static class BrakeableService {
+	    public BehaviorSubject<String> items = BehaviorSubject.create("Greet");
+	    
+	    public void play() {
+	        items.onNext("Hello");
+	        items.onNext("and");
+	        items.onNext("goodbye");
+	    }
+	}
+	
+	public static class BrakeableService2 {
+	    private final BehaviorSubject<String> items = BehaviorSubject.create("Greet");
+
+	    public BehaviorSubject<String> getValuesUnsafe() {
+	        return items;
+	    }
+	    
+	    public Observable<String> getValuesUnsafe2() {
+	        return items;
+	    }
+	    
+	    public void play() {
+	        items.onNext("Hello");
+	        items.onNext("and");
+	        items.onNext("goodbye");
+	    }
+	}
+	
+	public static class SafeService {
+		private final BehaviorSubject<String> items = BehaviorSubject.create("Greet");
+		 
+		public Observable<String> getValues() {
+	        return items.asObservable();
+	    }
+		
+		public void play() {
+	        items.onNext("Hello");
+	        items.onNext("and");
+	        items.onNext("goodbye");
+	    }
+	}
+	
+	public void exampleModifyReference() {
+		BrakeableService service = new BrakeableService();
+		service.items.subscribe((i) -> System.out.println("Before: " + i));
+		service.items = BehaviorSubject.create("Later");
+		service.items.subscribe((i) -> System.out.println("After: " + i));
+		service.play();
+		
+		// Before: Greet
+		// After: Greet
+		// After: Hello
+		// After: and
+		// After: goodbye
+	}
+	
+	public void examplePush() {
+		BrakeableService2 service = new BrakeableService2();
+		
+		service.getValuesUnsafe().subscribe(System.out::println);
+		service.getValuesUnsafe().onNext("GARBAGE");
+		service.play();
+		
+		// Greet
+		// GARBAGE
+		// Hello
+		// and
+		// goodbye
+	}
+	
+	public void examplePush2() {
+		BrakeableService2 service = new BrakeableService2();
+		
+		service.getValuesUnsafe2().subscribe(System.out::println);
+		if (service.getValuesUnsafe2() instanceof Subject<?, ?>) {
+			@SuppressWarnings("unchecked")
+			Subject<String, String> subject = (Subject<String, String>) service.getValuesUnsafe2();
+			subject.onNext("GARBAGE");
+		}
+		service.play();
+		
+		// Greet
+		// GARBAGE
+		// Hello
+		// and
+		// goodbye
+	}
+	
+	public void exampleSafe() {
+		SafeService service = new SafeService();
+		
+		service.getValues().subscribe(System.out::println);
+		if (service.getValues() instanceof Subject<?, ?>) {
+			System.out.println("Not safe!");
+		}
+		service.play();
+		
+		// Greet
+		// Hello
+		// and
+		// goodbye
+	}
+	
+	
+	//
+	// Tests
+	//
+	
+	@Test
+	public void testModifyReference() {
+		TestSubscriber<String> testerBefore = new TestSubscriber<>();
+		TestSubscriber<String> testerAfter = new TestSubscriber<>();
+		
+		BrakeableService service = new BrakeableService();
+		service.items.subscribe(testerBefore);
+		service.items = BehaviorSubject.create("Later");
+		service.items.subscribe(testerAfter);
+		service.play();
+		
+		testerBefore.assertReceivedOnNext(Arrays.asList("Greet"));
+		testerAfter.assertReceivedOnNext(Arrays.asList(
+			"Later",
+			"Hello",
+			"and",
+			"goodbye"
+		));
+	}
+	
+	@Test
+	public void testPush() {
+		TestSubscriber<String> tester = new TestSubscriber<>();
+		
+		BrakeableService2 service = new BrakeableService2();
+		service.getValuesUnsafe().subscribe(tester);
+		service.getValuesUnsafe().onNext("GARBAGE");
+		service.play();
+		
+		tester.assertReceivedOnNext(Arrays.asList(
+			"Greet",
+			"GARBAGE",
+			"Hello",
+			"and",
+			"goodbye"
+		));
+	}
+	
+	@Test
+	public void testPush2() {
+		BrakeableService2 service = new BrakeableService2();
+		
+		assertTrue(service.getValuesUnsafe2() instanceof Subject<?,?>);
+	}
+	
+	@Test
+	public void testSafe() {
+		SafeService service = new SafeService();
+		
+		assertFalse(service.getValues() instanceof Subject<?,?>);
+	}
+	
+}
