net.jqwik.api.state

Interface ActionChain<S>

Type Parameters:

S - The type of the object going through state transformations

@API(status=EXPERIMENTAL,
     since="1.7.0")
public interface ActionChain<S>

A chain of transforming Actions that can be run for values of type S. Since the next action is usually created on demand, the current runState of a chain can be queried.

By default any action chain instance is not thread safe, i.e. you should not try to invoke run() concurrently.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ActionChain.ActionChainFacade
static class	ActionChain.RunningState

Method Summary

Modifier and Type	Method and Description
java.util.Optional<S>	finalState() The final state value after running an action chain.
ActionChain<S>	peek(java.util.function.Consumer<S> peeker) Observe the state transformations of a running chain by adding a peeker to an action chain.
S	run() Run the list through all transformations provided by the actions to create it.
ActionChain.RunningState	running() An action chain can be in different running states: NOT_RUN, RUNNING, FAILED, SUCEEDED
static <T> ActionChainArbitrary<T>	startWith(java.util.function.Supplier<? extends T> initialSupplier) Create arbitrary for a chain with a certain initial state.
java.util.List<java.lang.String>	transformations() Return list of all applied transformations.
java.util.List<Transformer<S>>	transformers() Return list of all used transformer instances.
default ActionChain<S>	withInvariant(java.util.function.Consumer<S> invariant) Add an unlabelled invariant to a sequence.
ActionChain<S>	withInvariant(@Nullable java.lang.String label, java.util.function.Consumer<S> invariant) Add a labelled invariant to a sequence.

Method Detail

startWith

static <T> ActionChainArbitrary<T> startWith(java.util.function.Supplier<? extends T> initialSupplier)

Create arbitrary for a chain with a certain initial state.

Type Parameters:

T - The type of state to be transformed through the chain.

Parameters:

initialSupplier - function to create the initial state object

Returns:

new arbitrary instance

transformations

java.util.List<java.lang.String> transformations()

Return list of all applied transformations.

For a chain that has not been run this list is always empty.

Returns:

list of describing strings

transformers

@API(status=EXPERIMENTAL,
     since="1.7.1")
java.util.List<Transformer<S>> transformers()

Return list of all used transformer instances.

Checking transformer instances - e.g. if they are of a certain implementation type - only makes sense if the transformer's description string is NOT set explicitly, e.g. in an Action's description() method.

For a chain that has not been run this list is always empty.

Returns:

list of transformer instances

run

S run()

Run the list through all transformations provided by the actions to create it. Stop when either the maximum number of transformations is reached or if a Transformer.END_OF_CHAIN is being applied.

Returns:

the last resulting state of running through transformations

withInvariant

default ActionChain<S> withInvariant(java.util.function.Consumer<S> invariant)

Add an unlabelled invariant to a sequence.

Parameters:

invariant - will be checked after each successful action

Returns:

the same chain instance

See Also:

withInvariant(String, Consumer)

withInvariant

ActionChain<S> withInvariant(@Nullable java.lang.String label,
                             java.util.function.Consumer<S> invariant)

Add a labelled invariant to a sequence.

Parameters:

label - will show up in error messages when the invariant fails

invariant - will be checked after each successful action

Returns:

the same chain instance

See Also:

withInvariant(Consumer)

finalState

java.util.Optional<S> finalState()

The final state value after running an action chain.

Returns:

state or Optional.empty() if chain has not been run

running

ActionChain.RunningState running()

An action chain can be in different running states: NOT_RUN, RUNNING, FAILED, SUCEEDED

Returns:

a state object

peek

ActionChain<S> peek(java.util.function.Consumer<S> peeker)

Observe the state transformations of a running chain by adding a peeker to an action chain. The peeker will be called after each successful transformation but before checking invariants.

There can be more than one peeker.

Parameters:

peeker - A consumer of a state object

Returns:

the same chain instance