Manual Merge of Pull Request #212

rxjava-core/src/main/java/rx/Observable.java

@@ -41,6 +41,8 @@
 import rx.operators.OperationDefer;
 import rx.operators.OperationDematerialize;
 import rx.operators.OperationFilter;
+import rx.operators.OperationTake;
+import rx.operators.OperationTakeWhile;
 import rx.operators.OperationWhere;
 import rx.operators.OperationMap;
 import rx.operators.OperationMaterialize;
@@ -54,7 +56,6 @@
 import rx.operators.OperationScan;
 import rx.operators.OperationSkip;
 import rx.operators.OperationSynchronize;
-import rx.operators.OperationTake;
 import rx.operators.OperationTakeLast;
 import rx.operators.OperationToObservableFuture;
 import rx.operators.OperationToObservableIterable;
@@ -1779,7 +1780,7 @@ public static <T> Observable<T> takeLast(final Observable<T> items, final int co
      * @return
      */
     public static <T> Observable<T> takeWhile(final Observable<T> items, Func1<T, Boolean> predicate) {
-        return create(OperationTake.takeWhile(items, predicate));
+        return create(OperationTakeWhile.takeWhile(items, predicate));
     }
 
     /**
@@ -1811,16 +1812,18 @@ public Boolean call(T t) {
      * @return
      */
     public static <T> Observable<T> takeWhileWithIndex(final Observable<T> items, Func2<T, Integer, Boolean> predicate) {
-        return create(OperationTake.takeWhileWithIndex(items, predicate));
+        return create(OperationTakeWhile.takeWhileWithIndex(items, predicate));
     }
 
     public static <T> Observable<T> takeWhileWithIndex(final Observable<T> items, Object predicate) {
         @SuppressWarnings("rawtypes")
         final FuncN _f = Functions.from(predicate);
 
-        return create(OperationTake.takeWhileWithIndex(items, new Func2<T, Integer, Boolean>() {
+        return create(OperationTakeWhile.takeWhileWithIndex(items, new Func2<T, Integer, Boolean>()
+        {
             @Override
-            public Boolean call(T t, Integer integer) {
+            public Boolean call(T t, Integer integer)
+            {
                 return (Boolean) _f.call(t, integer);
             }
         }));

rxjava-core/src/main/java/rx/operators/AbstractOperation.java

@@ -0,0 +1,256 @@
+package rx.operators;
+
+import static org.junit.Assert.*;
+
+import java.lang.Thread.UncaughtExceptionHandler;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.junit.Test;
+
+import rx.Observable;
+import rx.Observer;
+import rx.Subscription;
+import rx.subscriptions.Subscriptions;
+import rx.util.functions.Func1;
+
+/**
+ * Common utility functions for operator implementations and tests.
+ */
+/* package */class AbstractOperation
+{
+    private AbstractOperation() {
+    }
+
+    public static class UnitTest {
+
+        public static <T> Func1<Observer<T>, Subscription> assertTrustedObservable(final Func1<Observer<T>, Subscription> source)
+        {
+            return new Func1<Observer<T>, Subscription>()
+            {
+                @Override
+                public Subscription call(Observer<T> observer)
+                {
+                    return source.call(new TestingObserver<T>(observer));
+                }
+            };
+        }
+
+        public static class TestingObserver<T> implements Observer<T> {
+
+            private final Observer<T> actual;
+            private final AtomicBoolean isFinished = new AtomicBoolean(false);
+            private final AtomicBoolean isInCallback = new AtomicBoolean(false);
+
+            public TestingObserver(Observer<T> actual) {
+                this.actual = actual;
+            }
+
+            @Override
+            public void onCompleted() {
+                assertFalse("previous call to onCompleted() or onError()", !isFinished.compareAndSet(false, true));
+                assertFalse("concurrent callback pending", !isInCallback.compareAndSet(false, true));
+                actual.onCompleted();
+                isInCallback.set(false);
+            }
+
+            @Override
+            public void onError(Exception e) {
+                assertFalse("previous call to onCompleted() or onError()", !isFinished.compareAndSet(false, true));
+                assertFalse("concurrent callback pending", !isInCallback.compareAndSet(false, true));
+                actual.onError(e);
+                isInCallback.set(false);
+            }
+
+            @Override
+            public void onNext(T args) {
+                assertFalse("previous call to onCompleted() or onError()", isFinished.get());
+                assertFalse("concurrent callback pending", !isInCallback.compareAndSet(false, true));
+                actual.onNext(args);
+                isInCallback.set(false);
+            }
+
+        }
+
+        @Test(expected = AssertionError.class)
+        public void testDoubleCompleted() {
+            Observable.create(assertTrustedObservable(new Func1<Observer<String>, Subscription>()
+            {
+                @Override
+                public Subscription call(Observer<String> observer)
+                {
+                    observer.onCompleted();
+                    observer.onCompleted();
+                    return Subscriptions.empty();
+                }
+            })).lastOrDefault("end");
+
+        }
+
+        @Test(expected = AssertionError.class)
+        public void testCompletedError() {
+            Observable.create(assertTrustedObservable(new Func1<Observer<String>, Subscription>()
+            {
+                @Override
+                public Subscription call(Observer<String> observer)
+                {
+                    observer.onCompleted();
+                    observer.onError(new Exception());
+                    return Subscriptions.empty();
+                }
+            })).lastOrDefault("end");
+        }
+
+        @Test(expected = AssertionError.class)
+        public void testCompletedNext() {
+            Observable.create(assertTrustedObservable(new Func1<Observer<String>, Subscription>()
+            {
+                @Override
+                public Subscription call(Observer<String> observer)
+                {
+                    observer.onCompleted();
+                    observer.onNext("one");
+                    return Subscriptions.empty();
+                }
+            })).lastOrDefault("end");
+        }
+
+        @Test(expected = AssertionError.class)
+        public void testErrorCompleted() {
+            Observable.create(assertTrustedObservable(new Func1<Observer<String>, Subscription>()
+            {
+                @Override
+                public Subscription call(Observer<String> observer)
+                {
+                    observer.onError(new Exception());
+                    observer.onCompleted();
+                    return Subscriptions.empty();
+                }
+            })).lastOrDefault("end");
+        }
+
+        @Test(expected = AssertionError.class)
+        public void testDoubleError() {
+            Observable.create(assertTrustedObservable(new Func1<Observer<String>, Subscription>()
+            {
+                @Override
+                public Subscription call(Observer<String> observer)
+                {
+                    observer.onError(new Exception());
+                    observer.onError(new Exception());
+                    return Subscriptions.empty();
+                }
+            })).lastOrDefault("end");
+        }
+
+        @Test(expected = AssertionError.class)
+        public void testErrorNext() {
+            Observable.create(assertTrustedObservable(new Func1<Observer<String>, Subscription>()
+            {
+                @Override
+                public Subscription call(Observer<String> observer)
+                {
+                    observer.onError(new Exception());
+                    observer.onNext("one");
+                    return Subscriptions.empty();
+                }
+            })).lastOrDefault("end");
+        }
+
+        @Test
+        public void testNextCompleted() {
+            Observable.create(assertTrustedObservable(new Func1<Observer<String>, Subscription>()
+            {
+                @Override
+                public Subscription call(Observer<String> observer)
+                {
+                    observer.onNext("one");
+                    observer.onCompleted();
+                    return Subscriptions.empty();
+                }
+            })).lastOrDefault("end");
+        }
+
+        @Test
+        public void testConcurrentNextNext() {
+            final List<Thread> threads = new ArrayList<Thread>();
+            final AtomicReference<Throwable> threadFailure = new AtomicReference<Throwable>();
+            Observable.create(assertTrustedObservable(new Func1<Observer<String>, Subscription>()
+            {
+                @Override
+                public Subscription call(final Observer<String> observer)
+                {
+                    threads.add(new Thread(new Runnable()
+                    {
+                        @Override
+                        public void run()
+                        {
+                            observer.onNext("one");
+                        }
+                    }));
+                    threads.add(new Thread(new Runnable()
+                    {
+                        @Override
+                        public void run()
+                        {
+                            observer.onNext("two");
+                        }
+                    }));
+                    return Subscriptions.empty();
+                }
+            })).subscribe(new SlowObserver());
+            for (Thread thread : threads) {
+                thread.setUncaughtExceptionHandler(new UncaughtExceptionHandler()
+                {
+                    @Override
+                    public void uncaughtException(Thread thread, Throwable throwable)
+                    {
+                        threadFailure.set(throwable);
+                    }
+                });
+                thread.start();
+            }
+            for (Thread thread : threads) {
+                try {
+                    thread.join();
+                } catch (InterruptedException ignored) {
+                }
+            }
+            // Junit seems pretty bad about exposing test failures inside of created threads.
+            assertNotNull("exception thrown by thread", threadFailure.get());
+            assertEquals("class of exception thrown by thread", AssertionError.class, threadFailure.get().getClass());
+        }
+
+        private static class SlowObserver implements Observer<String>
+        {
+            @Override
+            public void onCompleted()
+            {
+                try {
+                    Thread.sleep(10);
+                } catch (InterruptedException ignored) {
+                }
+            }
+
+            @Override
+            public void onError(Exception e)
+            {
+                try {
+                    Thread.sleep(10);
+                } catch (InterruptedException ignored) {
+                }
+            }
+
+            @Override
+            public void onNext(String args)
+            {
+                try {
+                    Thread.sleep(10);
+                } catch (InterruptedException ignored) {
+                }
+            }
+        }
+    }
+}