net.jqwik.api

Interface Arbitrary<T>

Type Parameters:

T - The type of generated objects. Primitive objects (e.g. int, boolean etc.) are represented by their boxed type (e.g. Integer, Boolean).

All Known Subinterfaces:

ActionSequenceArbitrary<M>, BigDecimalArbitrary, BigIntegerArbitrary, ByteArbitrary, CharacterArbitrary, DoubleArbitrary, FloatArbitrary, IntegerArbitrary, LongArbitrary, ShortArbitrary, SizableArbitrary<U>, StringArbitrary

public interface Arbitrary<T>

The main interface for representing objects that can be generated and shrunk.

Method Summary

Modifier and Type	Method and Description
default <A> SizableArbitrary<A>	array(java.lang.Class<A> arrayClass) Create a new arbitrary of type T[] using the existing arbitrary for generating the elements of the array.
default java.util.Optional<ExhaustiveGenerator<T>>	exhaustive() Create the exhaustive generator for an arbitrary
default Arbitrary<T>	filter(java.util.function.Predicate<T> filterPredicate) Create a new arbitrary of the same type T that creates and shrinks the original arbitrary but only allows values that are accepted by the filterPredicate.
default Arbitrary<T>	fixGenSize(int genSize) Fix the genSize of an arbitrary so that it can no longer be influenced from outside
default <U> Arbitrary<U>	flatMap(java.util.function.Function<T,Arbitrary<U>> mapper) Create a new arbitrary of type U that uses the values of the existing arbitrary to create a new arbitrary using the mapper function.
RandomGenerator<T>	generator(int genSize) Create the random generator for an arbitrary
default Arbitrary<T>	injectNull(double nullProbability) Create a new arbitrary of the same type but inject null values with a probability of nullProbability.
default SizableArbitrary<java.util.Iterator<T>>	iterator() Create a new arbitrary of type Iterable<T> using the existing arbitrary for generating the elements of the stream.
default SizableArbitrary<java.util.List<T>>	list() Create a new arbitrary of type List<T> using the existing arbitrary for generating the elements of the list.
default <U> Arbitrary<U>	map(java.util.function.Function<T,U> mapper) Create a new arbitrary of type U that maps the values of the original arbitrary using the mapper function.
default Arbitrary<java.util.Optional<T>>	optional() Create a new arbitrary of type Optional<T> using the existing arbitrary for generating the elements of the stream.
default SizableArbitrary<java.util.Set<T>>	set() Create a new arbitrary of type Set<T> using the existing arbitrary for generating the elements of the set.
default SizableArbitrary<java.util.stream.Stream<T>>	stream() Create a new arbitrary of type Stream<T> using the existing arbitrary for generating the elements of the stream.
default Arbitrary<T>	unique() Create a new arbitrary of the same type T that creates and shrinks the original arbitrary but will never generate the same value twice.
default Arbitrary<T>	withSamples(T... samples) Create a new arbitrary of the same type but inject values in samples first before continuing with standard value generation.

Method Detail

generator

RandomGenerator<T> generator(int genSize)

Create the random generator for an arbitrary

Parameters:

genSize - a very unspecific configuration parameter that can be used to influence the configuration and behaviour of a random generator if and only if the generator wants to be influenced. Many generators are independent of genSize. The default value of genSize is the number of tries configured for a property. Use fixGenSize(int) to fix the parameter for a given arbitrary.

Returns:

a new random generator instance

exhaustive

default java.util.Optional<ExhaustiveGenerator<T>> exhaustive()

Create the exhaustive generator for an arbitrary

Returns:

a new exhaustive generator or Optional.empty() if it cannot be created.

filter

default Arbitrary<T> filter(java.util.function.Predicate<T> filterPredicate)

Create a new arbitrary of the same type T that creates and shrinks the original arbitrary but only allows values that are accepted by the filterPredicate.

Throws:

JqwikException - if filtering will fail to come up with a value after 10000 tries

map

default <U> Arbitrary<U> map(java.util.function.Function<T,U> mapper)

Create a new arbitrary of type U that maps the values of the original arbitrary using the mapper function.

flatMap

default <U> Arbitrary<U> flatMap(java.util.function.Function<T,Arbitrary<U>> mapper)

Create a new arbitrary of type U that uses the values of the existing arbitrary to create a new arbitrary using the mapper function.

injectNull

default Arbitrary<T> injectNull(double nullProbability)

Create a new arbitrary of the same type but inject null values with a probability of nullProbability.

unique

default Arbitrary<T> unique()

Create a new arbitrary of the same type T that creates and shrinks the original arbitrary but will never generate the same value twice.

Throws:

JqwikException - if filtering will fail to come up with a value after 10000 tries

withSamples

default Arbitrary<T> withSamples(T... samples)

Create a new arbitrary of the same type but inject values in samples first before continuing with standard value generation.

fixGenSize

default Arbitrary<T> fixGenSize(int genSize)

Fix the genSize of an arbitrary so that it can no longer be influenced from outside

list

default SizableArbitrary<java.util.List<T>> list()

Create a new arbitrary of type List<T> using the existing arbitrary for generating the elements of the list.

set

default SizableArbitrary<java.util.Set<T>> set()

Create a new arbitrary of type Set<T> using the existing arbitrary for generating the elements of the set.

stream

default SizableArbitrary<java.util.stream.Stream<T>> stream()

Create a new arbitrary of type Stream<T> using the existing arbitrary for generating the elements of the stream.

iterator

default SizableArbitrary<java.util.Iterator<T>> iterator()

Create a new arbitrary of type Iterable<T> using the existing arbitrary for generating the elements of the stream.

array

default <A> SizableArbitrary<A> array(java.lang.Class<A> arrayClass)

Create a new arbitrary of type T[] using the existing arbitrary for generating the elements of the array.

Parameters:

arrayClass - The arrays class to create, e.g. String[].class. This is required due to limitations in Java's reflection capabilities.

optional

default Arbitrary<java.util.Optional<T>> optional()

Create a new arbitrary of type Optional<T> using the existing arbitrary for generating the elements of the stream. The new arbitrary also generates Optional.empty() values with a probability of 0.05 (i.e. 1 in 20).