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TestObserver
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‎rxjava-core/src/main/java/rx/Notification.java

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@@ -26,12 +26,35 @@ public class Notification<T> {
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private final Throwable throwable;
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private final T value;
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public static <T> Notification<T> createOnNext(T t) {
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return new Notification<T>(Kind.OnNext, t, null);
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}
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public static <T> Notification<T> createOnError(Throwable e) {
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return new Notification<T>(Kind.OnError, null, e);
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}
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public static <T> Notification<T> createOnCompleted() {
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return new Notification<T>(Kind.OnCompleted, null, null);
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}
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public static <T> Notification<T> createOnCompleted(Class<T> type) {
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return new Notification<T>(Kind.OnCompleted, null, null);
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}
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private Notification(Kind kind, T value, Throwable e) {
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this.value = value;
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this.throwable = e;
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this.kind = kind;
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}
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/**
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* A constructor used to represent an onNext notification.
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*
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* @param value
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* The data passed to the onNext method.
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*/
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@Deprecated
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public Notification(T value) {
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this.value = value;
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this.throwable = null;
@@ -43,7 +66,9 @@ public Notification(T value) {
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*
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* @param exception
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* The exception passed to the onError notification.
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* @deprecated Because type Throwable can't disambiguate the constructors if both onNext and onError are type "Throwable"
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*/
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@Deprecated
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public Notification(Throwable exception) {
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this.throwable = exception;
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this.value = null;
@@ -53,6 +78,7 @@ public Notification(Throwable exception) {
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/**
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* A constructor used to represent an onCompleted notification.
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*/
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@Deprecated
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public Notification() {
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this.throwable = null;
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this.value = null;

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

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Original file line numberDiff line numberDiff line change
@@ -72,7 +72,7 @@ protected Observer(Observer<?> op) {
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*
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* @param args
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*/
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public abstract void onNext(T args);
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public abstract void onNext(T t);
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/**
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* Used to register an unsubscribe callback.

‎rxjava-core/src/main/java/rx/observers/EmptyObserver.java

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@@ -0,0 +1,25 @@
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package rx.observers;
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import rx.Observer;
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/**
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* Observer that does nothing... including swallowing errors.
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*/
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public class EmptyObserver<T> extends Observer<T> {
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@Override
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public void onCompleted() {
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}
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@Override
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public void onError(Throwable e) {
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}
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@Override
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public void onNext(T args) {
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}
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}

‎rxjava-core/src/main/java/rx/observers/TestObserver.java

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@@ -0,0 +1,115 @@
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/**
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* Copyright 2014 Netflix, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package rx.observers;
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import java.util.ArrayList;
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import java.util.Collections;
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import java.util.List;
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import rx.Notification;
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import rx.Observer;
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/**
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* Observer usable for unit testing to perform assertions, inspect received events or wrap a mocked Observer.
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*/
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public class TestObserver<T> extends Observer<T> {
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private final Observer<Object> EMPTY = new EmptyObserver<Object>();
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private final Observer<T> delegate;
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private final ArrayList<T> onNextEvents = new ArrayList<T>();
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private final ArrayList<Throwable> onErrorEvents = new ArrayList<Throwable>();
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private final ArrayList<Notification<T>> onCompletedEvents = new ArrayList<Notification<T>>();
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public TestObserver(Observer<T> delegate) {
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this.delegate = delegate;
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}
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@SuppressWarnings("unchecked")
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public TestObserver() {
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this.delegate = (Observer<T>) EMPTY;
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}
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@Override
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public void onCompleted() {
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onCompletedEvents.add(Notification.<T> createOnCompleted());
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delegate.onCompleted();
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}
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public List<Notification<T>> getOnCompletedEvents() {
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return Collections.unmodifiableList(onCompletedEvents);
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}
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@Override
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public void onError(Throwable e) {
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onErrorEvents.add(e);
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delegate.onError(e);
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}
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public List<Throwable> getOnErrorEvents() {
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return Collections.unmodifiableList(onErrorEvents);
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}
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@Override
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public void onNext(T t) {
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onNextEvents.add(t);
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delegate.onNext(t);
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}
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public List<T> getOnNextEvents() {
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return Collections.unmodifiableList(onNextEvents);
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}
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public void assertReceivedOnNext(List<T> items) {
77+
if (onNextEvents.size() != items.size()) {
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throw new AssertionError("Number of items does not match. Provided: " + items.size() + " Actual: " + onNextEvents.size());
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}
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for (int i = 0; i < items.size(); i++) {
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if (items.get(i) == null) {
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// check for null equality
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if (onNextEvents.get(i) != null) {
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throw new AssertionError("Value at index: " + i + " expected to be [null] but was: [" + onNextEvents.get(i) + "]");
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}
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} else if (!items.get(i).equals(onNextEvents.get(i))) {
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throw new AssertionError("Value at index: " + i + " expected to be [" + items.get(i) + "] but was: [" + onNextEvents.get(i) + "]");
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}
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}
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}
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/**
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* Assert that a single terminal event occurred, either onCompleted or onError.
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*/
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public void assertTerminalEvent() {
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if (onErrorEvents.size() > 1) {
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throw new AssertionError("Too many onError events: " + onErrorEvents.size());
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}
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if (onCompletedEvents.size() > 1) {
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throw new AssertionError("Too many onCompleted events: " + onCompletedEvents.size());
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}
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if (onCompletedEvents.size() == 1 && onErrorEvents.size() == 1) {
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throw new AssertionError("Received both an onError and onCompleted. Should be one or the other.");
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}
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if (onCompletedEvents.size() == 0 && onErrorEvents.size() == 0) {
111+
throw new AssertionError("No terminal events received.");
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}
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}
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}

‎rxjava-core/src/test/java/rx/observers/TestObserverTest.java

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@@ -0,0 +1,121 @@
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/**
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* Copyright 2014 Netflix, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
8+
* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
11+
* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13+
* See the License for the specific language governing permissions and
14+
* limitations under the License.
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*/
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package rx.observers;
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import static org.junit.Assert.*;
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import static org.mockito.Mockito.*;
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import java.util.Arrays;
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import org.junit.Rule;
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import org.junit.Test;
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import org.junit.rules.ExpectedException;
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import org.mockito.InOrder;
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import rx.Observable;
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import rx.Observer;
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import rx.subjects.PublishSubject;
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public class TestObserverTest {
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@Rule
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public ExpectedException thrown = ExpectedException.none();
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@Test
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public void testAssert() {
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Observable<Integer> oi = Observable.from(Arrays.asList(1, 2));
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TestObserver<Integer> o = new TestObserver<Integer>();
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oi.subscribe(o);
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o.assertReceivedOnNext(Arrays.asList(1, 2));
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assertEquals(2, o.getOnNextEvents().size());
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o.assertTerminalEvent();
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}
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@Test
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public void testAssertNotMatchCount() {
50+
Observable<Integer> oi = Observable.from(Arrays.asList(1, 2));
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TestObserver<Integer> o = new TestObserver<Integer>();
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oi.subscribe(o);
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thrown.expect(AssertionError.class);
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thrown.expectMessage("Number of items does not match. Provided: 1 Actual: 2");
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o.assertReceivedOnNext(Arrays.asList(1));
58+
assertEquals(2, o.getOnNextEvents().size());
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o.assertTerminalEvent();
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}
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@Test
63+
public void testAssertNotMatchValue() {
64+
Observable<Integer> oi = Observable.from(Arrays.asList(1, 2));
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TestObserver<Integer> o = new TestObserver<Integer>();
66+
oi.subscribe(o);
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thrown.expect(AssertionError.class);
69+
thrown.expectMessage("Value at index: 1 expected to be [3] but was: [2]");
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o.assertReceivedOnNext(Arrays.asList(1, 3));
72+
assertEquals(2, o.getOnNextEvents().size());
73+
o.assertTerminalEvent();
74+
}
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@Test
77+
public void testAssertTerminalEventNotReceived() {
78+
PublishSubject<Integer> p = PublishSubject.create();
79+
TestObserver<Integer> o = new TestObserver<Integer>();
80+
p.toObservable().subscribe(o);
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p.onNext(1);
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p.onNext(2);
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thrown.expect(AssertionError.class);
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thrown.expectMessage("No terminal events received.");
87+
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o.assertReceivedOnNext(Arrays.asList(1, 2));
89+
assertEquals(2, o.getOnNextEvents().size());
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o.assertTerminalEvent();
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}
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@Test
94+
public void testWrappingMock() {
95+
Observable<Integer> oi = Observable.from(Arrays.asList(1, 2));
96+
@SuppressWarnings("unchecked")
97+
Observer<Integer> mockObserver = mock(Observer.class);
98+
oi.subscribe(new TestObserver<Integer>(mockObserver));
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InOrder inOrder = inOrder(mockObserver);
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inOrder.verify(mockObserver, times(1)).onNext(1);
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inOrder.verify(mockObserver, times(1)).onNext(2);
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inOrder.verify(mockObserver, times(1)).onCompleted();
104+
inOrder.verifyNoMoreInteractions();
105+
}
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@Test
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public void testWrappingMockWhenUnsubscribeInvolved() {
109+
Observable<Integer> oi = Observable.from(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9)).take(2);
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@SuppressWarnings("unchecked")
111+
Observer<Integer> mockObserver = mock(Observer.class);
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oi.subscribe(new TestObserver<Integer>(mockObserver));
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InOrder inOrder = inOrder(mockObserver);
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inOrder.verify(mockObserver, times(1)).onNext(1);
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inOrder.verify(mockObserver, times(1)).onNext(2);
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inOrder.verify(mockObserver, times(1)).onCompleted();
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inOrder.verifyNoMoreInteractions();
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}
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}

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