reactor.test

Interface StepVerifier

public interface StepVerifier

A StepVerifier is a verifiable, blocking script usually produced by terminal expectations of the said script.

• Create a StepVerifier builder using create(org.reactivestreams.Publisher<? extends T>) or withVirtualTime(java.util.function.Supplier<? extends org.reactivestreams.Publisher<? extends T>>)
• Set individual up value expectations using StepVerifier.Step.expectNext(T...), StepVerifier.Step.expectNextMatches(Predicate), StepVerifier.Step.expectNextCount(long) or StepVerifier.Step.expectNextSequence(Iterable) .
• Set up subscription actions using either thenRequest(long) or thenCancel().
• Build the StepVerifier using StepVerifier.LastStep.expectComplete(), StepVerifier.LastStep.expectError(), expectError(Class), expectErrorMatches(Predicate), or StepVerifier.LastStep.thenCancel().
• Subscribe the built StepVerifier to a Publisher.
• Verify the expectations using either verify() or verify(Duration).
• If any expectations failed, an AssertionError will be thrown indicating the failures.

For example:

 StepVerifier.create(Flux.just("foo", "bar"))
   .expectNext("foo")
   .expectNext("bar")
   .expectComplete()
   .verify();
 

Author:

Arjen Poutsma, Stephane Maldini

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	StepVerifier.Assertions Exposes post-verification state assertions.
static interface	StepVerifier.FirstStep<T> Define a builder for explicitly expecting an initializing Subscription as first signal.
static interface	StepVerifier.LastStep Define a builder for terminal states.
static interface	StepVerifier.Step<T> Define a builder for expecting main sequence individual signals.

Method Summary

Modifier and Type	Method and Description
static <T> StepVerifier.FirstStep<T>	create(Publisher<? extends T> publisher) Prepare a new StepVerifier in an uncontrolled environment: Expect non-virtual blocking wait via StepVerifier.Step.thenAwait().
static <T> StepVerifier.FirstStep<T>	create(Publisher<? extends T> publisher, long n) Prepare a new StepVerifier in an uncontrolled environment: Expect non-virtual blocking wait via StepVerifier.Step.thenAwait().
static <T> StepVerifier.FirstStep<T>	create(Publisher<? extends T> publisher, StepVerifierOptions options) Prepare a new StepVerifier in an uncontrolled environment: Expect non-virtual blocking wait via StepVerifier.Step.thenAwait().
StepVerifier	log() Activate debug logging of a description of the test scenario, as well as some details about certain verification steps.
java.time.Duration	verify() Verify the signals received by this subscriber.
java.time.Duration	verify(java.time.Duration duration) Verify the signals received by this subscriber.
StepVerifier.Assertions	verifyThenAssertThat() Verifies the signals received by this subscriber, then exposes various assertion methods on the final state.
static <T> StepVerifier.FirstStep<T>	withVirtualTime(long n, java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier) Deprecated. to be removed in 3.1.0 for parameter ordering harmonization. Please use withVirtualTime(Supplier, long) instead.
static <T> StepVerifier.FirstStep<T>	withVirtualTime(long n, java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier, java.util.function.Supplier<? extends VirtualTimeScheduler> vtsLookup) Deprecated. to be removed in 3.1.0 for parameter ordering harmonization. Please use withVirtualTime(Supplier, Supplier, long) instead.
static <T> StepVerifier.FirstStep<T>	withVirtualTime(java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier) Prepare a new StepVerifier in a controlled environment using VirtualTimeScheduler to schedule and expect virtual wait via StepVerifier.Step.thenAwait().
static <T> StepVerifier.FirstStep<T>	withVirtualTime(java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier, long n) Prepare a new StepVerifier in a controlled environment using VirtualTimeScheduler to schedule and expect virtual wait via StepVerifier.Step.thenAwait().
static <T> StepVerifier.FirstStep<T>	withVirtualTime(java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier, StepVerifierOptions options) Create a new StepVerifier in a parameterized environment using passed VirtualTimeScheduler to schedule and expect virtual wait via StepVerifier.Step.thenAwait().
static <T> StepVerifier.FirstStep<T>	withVirtualTime(java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier, java.util.function.Supplier<? extends VirtualTimeScheduler> vtsLookup, long n) Create a new StepVerifier in a parameterized environment using passed VirtualTimeScheduler to schedule and expect virtual wait via StepVerifier.Step.thenAwait().

Method Detail

create

static <T> StepVerifier.FirstStep<T> create(Publisher<? extends T> publisher)

Prepare a new StepVerifier in an uncontrolled environment: Expect non-virtual blocking wait via StepVerifier.Step.thenAwait(). Each verify() will fully (re)play the scenario.

Parameters:

publisher - the publisher to subscribe to

Returns:

the Duration of the verification

Throws:

AssertionError - in case of expectation failures

create

static <T> StepVerifier.FirstStep<T> create(Publisher<? extends T> publisher,
                                            long n)

Prepare a new StepVerifier in an uncontrolled environment: Expect non-virtual blocking wait via StepVerifier.Step.thenAwait(). Each verify() will fully (re)play the scenario. The verification will request a specified amount of values.

Parameters:

publisher - the publisher to subscribe to

n - the amount of items to request

Returns:

the Duration of the verification

Throws:

AssertionError - in case of expectation failures, or when the verification times out

create

static <T> StepVerifier.FirstStep<T> create(Publisher<? extends T> publisher,
                                            StepVerifierOptions options)

Prepare a new StepVerifier in an uncontrolled environment: Expect non-virtual blocking wait via StepVerifier.Step.thenAwait(). Each verify() will fully (re)play the scenario. The verification will request a specified amount of values according to the options passed.

Parameters:

publisher - the publisher to subscribe to

options - the options for the verification

Returns:

the Duration of the verification

Throws:

AssertionError - in case of expectation failures, or when the verification times out

withVirtualTime

static <T> StepVerifier.FirstStep<T> withVirtualTime(java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier)

Prepare a new StepVerifier in a controlled environment using VirtualTimeScheduler to schedule and expect virtual wait via StepVerifier.Step.thenAwait(). Each verify() will fully (re)play the scenario. The verification will request an unbounded amount of values.

Type Parameters:

T - the type of the subscriber

Parameters:

scenarioSupplier - a mandatory supplier of the Publisher to test

Returns:

a builder for setting up value expectations

withVirtualTime

@Deprecated
static <T> StepVerifier.FirstStep<T> withVirtualTime(long n,
                                                                 java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier)

Deprecated. to be removed in 3.1.0 for parameter ordering harmonization. Please use withVirtualTime(Supplier, long) instead.

withVirtualTime

static <T> StepVerifier.FirstStep<T> withVirtualTime(java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier,
                                                     long n)

Prepare a new StepVerifier in a controlled environment using VirtualTimeScheduler to schedule and expect virtual wait via StepVerifier.Step.thenAwait(). Each verify() will fully (re)play the scenario. The verification will request a specified amount of values.

Type Parameters:

T - the type of the subscriber

Parameters:

scenarioSupplier - a mandatory supplier of the Publisher to test

n - the amount of items to request (must be >= 0)

Returns:

a builder for setting up value expectations

withVirtualTime

@Deprecated
static <T> StepVerifier.FirstStep<T> withVirtualTime(long n,
                                                                 java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier,
                                                                 java.util.function.Supplier<? extends VirtualTimeScheduler> vtsLookup)

Deprecated. to be removed in 3.1.0 for parameter ordering harmonization. Please use withVirtualTime(Supplier, Supplier, long) instead.

withVirtualTime

static <T> StepVerifier.FirstStep<T> withVirtualTime(java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier,
                                                     java.util.function.Supplier<? extends VirtualTimeScheduler> vtsLookup,
                                                     long n)

Create a new StepVerifier in a parameterized environment using passed VirtualTimeScheduler to schedule and expect virtual wait via StepVerifier.Step.thenAwait(). Each verify() will fully (re)play the scenario. The verification will request a specified amount of values.

Type Parameters:

T - the type of the subscriber

Parameters:

scenarioSupplier - a mandatory supplier of the Publisher to test

vtsLookup - a mandatory VirtualTimeScheduler lookup to use in thenAwait

n - the amount of items to request (must be >= 0)

Returns:

a builder for setting up value expectations

withVirtualTime

static <T> StepVerifier.FirstStep<T> withVirtualTime(java.util.function.Supplier<? extends Publisher<? extends T>> scenarioSupplier,
                                                     StepVerifierOptions options)

Create a new StepVerifier in a parameterized environment using passed VirtualTimeScheduler to schedule and expect virtual wait via StepVerifier.Step.thenAwait(). Each verify() will fully (re)play the scenario. The verification will request a specified amount of values according to the provided options.

Type Parameters:

T - the type of the subscriber

Parameters:

scenarioSupplier - a mandatory supplier of the Publisher to test

options - the verification options, including a mandatory VirtualTimeScheduler lookup to use in thenAwait

Returns:

a builder for setting up value expectations

log

StepVerifier log()

Activate debug logging of a description of the test scenario, as well as some details about certain verification steps.

Returns:

the verifier for final verify() call

verify

java.time.Duration verify()
                   throws AssertionError

Verify the signals received by this subscriber. This method will block indefinitely until the stream has been terminated (either through Subscriber.onComplete(), Subscriber.onError(Throwable) or Subscription.cancel()).

Returns:

the Duration of the verification

Throws:

AssertionError - in case of expectation failures

verify

java.time.Duration verify(java.time.Duration duration)
                   throws AssertionError

Verify the signals received by this subscriber. This method will block for the given duration or until the stream has been terminated (either through Subscriber.onComplete(), Subscriber.onError(Throwable) or Subscription.cancel()).

Returns:

the Duration of the verification

Throws:

AssertionError - in case of expectation failures, or when the verification times out

verifyThenAssertThat

StepVerifier.Assertions verifyThenAssertThat()

Verifies the signals received by this subscriber, then exposes various assertion methods on the final state.

Note this method will block indefinitely until the stream has been terminated (either through Subscriber.onComplete(), Subscriber.onError(Throwable) or Subscription.cancel()).

Returns:

the Duration of the verification

Throws:

AssertionError - in case of expectation failures