Merge pull request ReactiveX#2948 from ReactiveX/TestSubscriberPlus

More assertions for TestSubscriber

Author: benjchristensen

src/main/java/rx/observers/TestSubscriber.java

@@ -15,10 +15,13 @@
  */
 package rx.observers;
 
-import java.util.List;
+import java.util.*;
 import java.util.concurrent.*;
 
 import rx.*;
+import rx.Observer;
+import rx.annotations.Experimental;
+import rx.exceptions.CompositeException;
 
 /**
  * A {@code TestSubscriber} is a variety of {@link Subscriber} that you can use for unit testing, to perform
@@ -29,34 +32,72 @@ public class TestSubscriber<T> extends Subscriber<T> {
     private final TestObserver<T> testObserver;
     private final CountDownLatch latch = new CountDownLatch(1);
     private volatile Thread lastSeenThread;
+    /** Holds the initial request value. */
+    private final long initialRequest;
+    /** The shared no-op observer. */
+    private static final Observer<Object> INERT = new Observer<Object>() {
 
-    public TestSubscriber(Subscriber<T> delegate) {
+        @Override
+        public void onCompleted() {
+            // do nothing
+        }
+
+        @Override
+        public void onError(Throwable e) {
+            // do nothing
+        }
+
+        @Override
+        public void onNext(Object t) {
+            // do nothing
+        }
+
+    };
+
+    /**
+     * Constructs a TestSubscriber with the initial request to be requested from upstream.
+     * @param initialRequest the initial request value, negative value will revert to the default unbounded behavior
+     */
+    @SuppressWarnings("unchecked")
+    @Experimental
+    public TestSubscriber(long initialRequest) {
+        this((Observer<T>)INERT, initialRequest);
+    }
+    
+    /**
+     * Constructs a TestSubscriber with the initial request to be requested from upstream
+     * and a delegate Observer to wrap.
+     * @param initialRequest the initial request value, negative value will revert to the default unbounded behavior
+     * @param delegate the Observer instance to wrap
+     */
+    @Experimental
+    public TestSubscriber(Observer<T> delegate, long initialRequest) {
+        if (delegate == null) {
+            throw new NullPointerException();
+        }
         this.testObserver = new TestObserver<T>(delegate);
+        this.initialRequest = initialRequest;
+    }
+    
+    public TestSubscriber(Subscriber<T> delegate) {
+        this(delegate, -1);
     }
 
     public TestSubscriber(Observer<T> delegate) {
-        this.testObserver = new TestObserver<T>(delegate);
+        this(delegate, -1);
     }
 
     public TestSubscriber() {
-        this.testObserver = new TestObserver<T>(new Observer<T>() {
-
-            @Override
-            public void onCompleted() {
-                // do nothing
-            }
-
-            @Override
-            public void onError(Throwable e) {
-                // do nothing
-            }
-
-            @Override
-            public void onNext(T t) {
-                // do nothing
-            }
-
-        });
+        this(-1);
+    }
+    
+    @Override
+    public void onStart() {
+        if  (initialRequest >= 0) {
+            requestMore(initialRequest);
+        } else {
+            super.onStart();
+        }
     }
 
     /**
@@ -261,4 +302,121 @@ public void awaitTerminalEventAndUnsubscribeOnTimeout(long timeout, TimeUnit uni
     public Thread getLastSeenThread() {
         return lastSeenThread;
     }
-}
+    
+    /**
+     * Assert if there is exactly a single completion event.
+     */
+    @Experimental
+    public void assertCompleted() {
+        int s = testObserver.getOnCompletedEvents().size();
+        if (s == 0) {
+            throw new AssertionError("Not completed!");
+        } else
+        if (s > 1) {
+            throw new AssertionError("Completed multiple times: " + s);
+        }
+    }
+    /**
+     * Assert if there is no completion event.
+     */
+    @Experimental
+    public void assertNotCompleted() {
+        int s = testObserver.getOnCompletedEvents().size();
+        if (s == 1) {
+            throw new AssertionError("Completed!");
+        } else
+        if (s > 1) {
+            throw new AssertionError("Completed multiple times: " + s);
+        }
+    }
+    /**
+     * Assert if there is exactly one error event which is a subclass of the given class.
+     * @param clazz the class to check the error against.
+     */
+    @Experimental
+    public void assertError(Class<? extends Throwable> clazz) {
+        List<Throwable> err = testObserver.getOnErrorEvents();
+        if (err.size() == 0) {
+            throw new AssertionError("No errors");
+        } else
+        if (err.size() > 1) {
+            throw new AssertionError("Multiple errors: " + err.size(), new CompositeException(err));
+        } else
+        if (!clazz.isInstance(err.get(0))) {
+            throw new AssertionError("Exceptions differ; expected: " + clazz + ", actual: " + err.get(0), err.get(0));
+        }
+    }
+    /**
+     * Assert there is a single onError event with the exact exception.
+     * @param throwable the throwable to check
+     */
+    @Experimental
+    public void assertError(Throwable throwable) {
+        List<Throwable> err = testObserver.getOnErrorEvents();
+        if (err.size() == 0) {
+            throw new AssertionError("No errors");
+        } else
+        if (err.size() > 1) {
+            throw new AssertionError("Multiple errors: " + err.size(), new CompositeException(err));
+        } else
+        if (throwable.equals(err.get(0))) {
+            throw new AssertionError("Exceptions differ; expected: " + throwable + ", actual: " + err.get(0), err.get(0));
+        }
+    }
+    /**
+     * Assert for no onError and onCompleted events.
+     */
+    @Experimental
+    public void assertNoTerminalEvent() {
+        List<Throwable> err = testObserver.getOnErrorEvents();
+        int s = testObserver.getOnCompletedEvents().size();
+        if (err.size() > 0 || s > 0) {
+            if (err.isEmpty()) {
+                throw new AssertionError("Found " + err.size() + " errors and " + s + " completion events instead of none");
+            } else
+            if (err.size() == 1) {
+                throw new AssertionError("Found " + err.size() + " errors and " + s + " completion events instead of none", err.get(0));
+            } else {
+                throw new AssertionError("Found " + err.size() + " errors and " + s + " completion events instead of none", new CompositeException(err));
+            }
+        }
+    }
+    /**
+     * Assert if there are no onNext events received.
+     */
+    @Experimental
+    public void assertNoValues() {
+        int s = testObserver.getOnNextEvents().size();
+        if (s > 0) {
+            throw new AssertionError("No onNext events expected yet some received: " + s);
+        }
+    }
+    /**
+     * Assert if the given number of onNext events are received.
+     * @param count the expected number of onNext events
+     */
+    @Experimental
+    public void assertValueCount(int count) {
+        int s = testObserver.getOnNextEvents().size();
+        if (s != count) {
+            throw new AssertionError("Number of onNext events differ; expected: " + count + ", actual: " + s);
+        }
+    }
+    
+    /**
+     * Assert if the received onNext events, in order, are the specified values.
+     * @param values the values to check
+     */
+    @Experimental
+    public void assertValues(T... values) {
+        assertReceivedOnNext(Arrays.asList(values));
+    }
+    /**
+     * Assert if there is only a single received onNext event.
+     * @param values the values to check
+     */
+    @Experimental
+    public void assertValue(T value) {
+        assertReceivedOnNext(Collections.singletonList(value));
+    }
+}