Package rx.observers

Class TestSubscriber<T>

java.lang.Object
rx.Subscriber<T>
rx.observers.TestSubscriber<T>
Type Parameters:
T - the value type
All Implemented Interfaces:
Observer<T>, Subscription

public class TestSubscriber<T> extends Subscriber<T>
A TestSubscriber is a variety of Subscriber that you can use for unit testing, to perform assertions, inspect received events, or wrap a mocked Subscriber.
  • Field Details

    • delegate

      private final Observer<T> delegate
    • values

      private final List<T> values
    • errors

      private final List<Throwable> errors
    • completions

      private int completions
      The number of onCompleted() calls.
    • latch

      private final CountDownLatch latch
    • valueCount

      private volatile int valueCount
      Written after an onNext value has been added to the values list.
    • lastSeenThread

      private volatile Thread lastSeenThread
    • INERT

      private static final Observer<Object> INERT
      The shared no-op observer.
  • Constructor Details

    • TestSubscriber

      public TestSubscriber(long initialRequest)
      Constructs a TestSubscriber with the initial request to be requested from upstream.
      Parameters:
      initialRequest - the initial request value, negative value will revert to the default unbounded behavior
      Since:
      1.1.0
    • TestSubscriber

      public TestSubscriber(Observer<T> delegate, long initialRequest)
      Constructs a TestSubscriber with the initial request to be requested from upstream and a delegate Observer to wrap.
      Parameters:
      delegate - the Observer instance to wrap
      initialRequest - the initial request value, negative value will revert to the default unbounded behavior
      Throws:
      NullPointerException - if delegate is null
      Since:
      1.1.0
    • TestSubscriber

      public TestSubscriber(Subscriber<T> delegate)
      Constructs a TestSubscriber which requests Long.MAX_VALUE and delegates events to the given Subscriber.
      Parameters:
      delegate - the subscriber to delegate to.
      Throws:
      NullPointerException - if delegate is null
      Since:
      1.1.0
    • TestSubscriber

      public TestSubscriber(Observer<T> delegate)
      Constructs a TestSubscriber which requests Long.MAX_VALUE and delegates events to the given Observer.
      Parameters:
      delegate - the observer to delegate to.
      Throws:
      NullPointerException - if delegate is null
      Since:
      1.1.0
    • TestSubscriber

      public TestSubscriber()
      Constructs a TestSubscriber with an initial request of Long.MAX_VALUE and no delegation.
  • Method Details

    • create

      public static <T> TestSubscriber<T> create()
      Factory method to construct a TestSubscriber with an initial request of Long.MAX_VALUE and no delegation.
      Type Parameters:
      T - the value type
      Returns:
      the created TestSubscriber instance
      Since:
      1.1.0
    • create

      public static <T> TestSubscriber<T> create(long initialRequest)
      Factory method to construct a TestSubscriber with the given initial request amount and no delegation.
      Type Parameters:
      T - the value type
      Parameters:
      initialRequest - the initial request amount, negative values revert to the default unbounded mode
      Returns:
      the created TestSubscriber instance
      Since:
      1.1.0
    • create

      public static <T> TestSubscriber<T> create(Observer<T> delegate, long initialRequest)
      Factory method to construct a TestSubscriber which delegates events to the given Observer and issues the given initial request amount.
      Type Parameters:
      T - the value type
      Parameters:
      delegate - the observer to delegate events to
      initialRequest - the initial request amount, negative values revert to the default unbounded mode
      Returns:
      the created TestSubscriber instance
      Throws:
      NullPointerException - if delegate is null
      Since:
      1.1.0
    • create

      public static <T> TestSubscriber<T> create(Subscriber<T> delegate)
      Factory method to construct a TestSubscriber which delegates events to the given Subscriber and an issues an initial request of Long.MAX_VALUE.
      Type Parameters:
      T - the value type
      Parameters:
      delegate - the subscriber to delegate events to
      Returns:
      the created TestSubscriber instance
      Throws:
      NullPointerException - if delegate is null
      Since:
      1.1.0
    • create

      public static <T> TestSubscriber<T> create(Observer<T> delegate)
      Factory method to construct a TestSubscriber which delegates events to the given Observer and an issues an initial request of Long.MAX_VALUE.
      Type Parameters:
      T - the value type
      Parameters:
      delegate - the observer to delegate events to
      Returns:
      the created TestSubscriber instance
      Throws:
      NullPointerException - if delegate is null
      Since:
      1.1.0
    • onCompleted

      public void onCompleted()
      Notifies the Subscriber that the Observable has finished sending push-based notifications.

      The Observable will not call this method if it calls onError(java.lang.Throwable).

    • getOnCompletedEvents

      @Deprecated public List<Notification<T>> getOnCompletedEvents()
      Deprecated.
      use getCompletions() instead.
      Returns the Notifications representing each time this Subscriber was notified of sequence completion via onCompleted(), as a List.
      Returns:
      a list of Notifications representing calls to this Subscriber's onCompleted() method
    • getCompletions

      @Experimental public final int getCompletions()
      Returns the number of times onCompleted was called on this TestSubscriber.
      Returns:
      the number of times onCompleted was called on this TestSubscriber.
      Since:
      (if this graduates from Experimental/Beta to supported, replace this parenthetical with the release number)
    • onError

      public void onError(Throwable e)
      Notifies the Subscriber that the Observable has experienced an error condition.

      If the Observable calls this method, it will not thereafter call onNext(T) or onCompleted().

      Parameters:
      e - the exception encountered by the Observable
    • getOnErrorEvents

      public List<Throwable> getOnErrorEvents()
      Returns the Throwables this Subscriber was notified of via onError(java.lang.Throwable) as a List.
      Returns:
      a list of the Throwables that were passed to this Subscriber's onError(java.lang.Throwable) method
    • onNext

      public void onNext(T t)
      Provides the Subscriber with a new item to observe.

      The Observable may call this method 0 or more times.

      The Observable will not call this method again after it calls either onCompleted() or onError(java.lang.Throwable).

      Parameters:
      t - the item emitted by the Observable
    • getValueCount

      public final int getValueCount()
      Returns the committed number of onNext elements that are safe to be read from getOnNextEvents() other threads.
      Returns:
      the committed number of onNext elements
    • requestMore

      public void requestMore(long n)
      Allows calling the protected Subscriber.request(long) from unit tests.
      Parameters:
      n - the maximum number of items you want the Observable to emit to the Subscriber at this time, or Long.MAX_VALUE if you want the Observable to emit items at its own pace
    • getOnNextEvents

      public List<T> getOnNextEvents()
      Returns the sequence of items observed by this Subscriber, as an ordered List.
      Returns:
      a list of items observed by this Subscriber, in the order in which they were observed
    • assertReceivedOnNext

      public void assertReceivedOnNext(List<T> items)
      Asserts that a particular sequence of items was received by this Subscriber in order.
      Parameters:
      items - the sequence of items expected to have been observed
      Throws:
      AssertionError - if the sequence of items observed does not exactly match items
    • awaitValueCount

      @Experimental public final boolean awaitValueCount(int expected, long timeout, TimeUnit unit) throws InterruptedException
      Wait until the current committed value count is less than the expected amount by sleeping 1 unit at most timeout times and return true if at least the required amount of onNext values have been received.
      Parameters:
      expected - the expected number of onNext events
      timeout - the time to wait for the events
      unit - the time unit of waiting
      Returns:
      true if the expected number of onNext events happened
      Throws:
      InterruptedException - if the sleep is interrupted
      Since:
      (if this graduates from Experimental/Beta to supported, replace this parenthetical with the release number)
    • assertTerminalEvent

      public void assertTerminalEvent()
      Asserts that a single terminal event occurred, either onCompleted() or onError(java.lang.Throwable).
      Throws:
      AssertionError - if not exactly one terminal event notification was received
    • assertUnsubscribed

      public void assertUnsubscribed()
      Asserts that this Subscriber is unsubscribed.
      Throws:
      AssertionError - if this Subscriber is not unsubscribed
    • assertNoErrors

      public void assertNoErrors()
      Asserts that this Subscriber has received no onError notifications.
      Throws:
      AssertionError - if this Subscriber has received one or more onError notifications
    • awaitTerminalEvent

      public void awaitTerminalEvent()
      Blocks until this Subscriber receives a notification that the Observable is complete (either an onCompleted or onError notification).
      Throws:
      RuntimeException - if the Subscriber is interrupted before the Observable is able to complete
    • awaitTerminalEvent

      public void awaitTerminalEvent(long timeout, TimeUnit unit)
      Blocks until this Subscriber receives a notification that the Observable is complete (either an onCompleted or onError notification), or until a timeout expires.
      Parameters:
      timeout - the duration of the timeout
      unit - the units in which timeout is expressed
      Throws:
      RuntimeException - if the Subscriber is interrupted before the Observable is able to complete
    • awaitTerminalEventAndUnsubscribeOnTimeout

      public void awaitTerminalEventAndUnsubscribeOnTimeout(long timeout, TimeUnit unit)
      Blocks until this Subscriber receives a notification that the Observable is complete (either an onCompleted or onError notification), or until a timeout expires; if the Subscriber is interrupted before either of these events take place, this method unsubscribes the Subscriber from the Observable). If timeout expires then the Subscriber is unsubscribed from the Observable.
      Parameters:
      timeout - the duration of the timeout
      unit - the units in which timeout is expressed
    • getLastSeenThread

      public Thread getLastSeenThread()
      Returns the last thread that was in use when an item or notification was received by this Subscriber.
      Returns:
      the Thread on which this Subscriber last received an item or notification from the Observable it is subscribed to
    • assertCompleted

      public void assertCompleted()
      Asserts that there is exactly one completion event.
      Throws:
      AssertionError - if there were zero, or more than one, onCompleted events
      Since:
      1.1.0
    • assertNotCompleted

      public void assertNotCompleted()
      Asserts that there is no completion event.
      Throws:
      AssertionError - if there were one or more than one onCompleted events
      Since:
      1.1.0
    • assertError

      public void assertError(Class<? extends Throwable> clazz)
      Asserts that there is exactly one error event which is a subclass of the given class.
      Parameters:
      clazz - the class to check the error against.
      Throws:
      AssertionError - if there were zero, or more than one, onError events, or if the single onError event did not carry an error of a subclass of the given class
      Since:
      1.1.0
    • assertError

      public void assertError(Throwable throwable)
      Asserts that there is a single onError event with the exact exception.
      Parameters:
      throwable - the throwable to check
      Throws:
      AssertionError - if there were zero, or more than one, onError events, or if the single onError event did not carry an error that matches the specified throwable
      Since:
      1.1.0
    • assertNoTerminalEvent

      public void assertNoTerminalEvent()
      Asserts that there are no onError and onCompleted events.
      Throws:
      AssertionError - if there was either an onError or onCompleted event
      Since:
      1.1.0
    • assertNoValues

      public void assertNoValues()
      Asserts that there are no onNext events received.
      Throws:
      AssertionError - if there were any onNext events
      Since:
      1.1.0
    • assertValueCount

      public void assertValueCount(int count)
      Asserts that the given number of onNext events are received.
      Parameters:
      count - the expected number of onNext events
      Throws:
      AssertionError - if there were more or fewer onNext events than specified by count
      Since:
      1.1.0
    • assertValues

      public void assertValues(T... values)
      Asserts that the received onNext events, in order, are the specified items.
      Parameters:
      values - the items to check
      Throws:
      AssertionError - if the items emitted do not exactly match those specified by values
      Since:
      1.1.0
    • assertValue

      public void assertValue(T value)
      Asserts that there is only a single received onNext event and that it marks the emission of a specific item.
      Parameters:
      value - the item to check
      Throws:
      AssertionError - if the Observable does not emit only the single item specified by value
      Since:
      1.1.0
    • assertionError

      final void assertionError(String message)
      Combines an assertion error message with the current completion and error state of this TestSubscriber, giving more information when some assertXXX check fails.
      Parameters:
      message - the message to use for the error