net.jqwik.api

Class Arbitraries

java.lang.Object

net.jqwik.api.Arbitraries

@API(status=STABLE,
     since="1.0")
public class Arbitraries
extends java.lang.Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Arbitraries.ArbitrariesFacade

Method Summary

Modifier and Type	Method and Description
static BigDecimalArbitrary	bigDecimals() Create an arbitrary that generates values of type BigDecimal.
static BigIntegerArbitrary	bigIntegers() Create an arbitrary that generates values of type BigInteger.
static ByteArbitrary	bytes() Create an arbitrary that generates values of type Byte.
static CharacterArbitrary	chars() Create an arbitrary that generates values of type Character.
static <T> Arbitrary<T>	constant(T value) Create an arbitrary that will always generate the same value.
static <T> Arbitrary<T>	create(java.util.function.Supplier<T> supplier) Create an arbitrary that will use a supplier to generate a value.
static <T> Arbitrary<T>	defaultFor(java.lang.Class<T> type, java.lang.Class<?>... typeParameters) Find a registered arbitrary that will be used to generate values of type T.
static <T> Arbitrary<T>	defaultFor(TypeUsage typeUsage) Find a registered arbitrary that will be used to generate values of type T.
static DoubleArbitrary	doubles() Create an arbitrary that generates values of type Double.
static FloatArbitrary	floats() Create an arbitrary that generates values of type Float.
static <T> TypeArbitrary<T>	forType(java.lang.Class<T> targetType) Create an arbitrary for type T that will by default use the type's public constructors and public factory methods.
static <T> Arbitrary<T>	frequency(java.util.List<Tuple.Tuple2<java.lang.Integer,T>> frequencies) Create an arbitrary that will randomly choose between all given values of the same type T.
static <T> Arbitrary<T>	frequency(Tuple.Tuple2<java.lang.Integer,T>... frequencies) Create an arbitrary that will randomly choose between all given values of the same type T.
static <T> Arbitrary<T>	frequencyOf(java.util.List<Tuple.Tuple2<java.lang.Integer,Arbitrary<T>>> frequencies) Create an arbitrary that will randomly choose between all given arbitraries of the same type T.
static <T> Arbitrary<T>	frequencyOf(Tuple.Tuple2<java.lang.Integer,Arbitrary<T>>... frequencies) Create an arbitrary that will randomly choose between all given arbitraries of the same type T.
static <T> Arbitrary<T>	fromGenerator(RandomGenerator<T> generator) Create an arbitrary of type T from a corresponding generator of type T.
static IntegerArbitrary	integers() Create an arbitrary that generates values of type Integer.
static <T> Arbitrary<T>	lazy(java.util.function.Supplier<Arbitrary<T>> arbitrarySupplier) Create an arbitrary that will evaluate arbitrarySupplier as soon as it is used for generating values.
static LongArbitrary	longs() Create an arbitrary that generates values of type Long.
static Arbitrary<java.lang.Character>	of(char[] values) Create an arbitrary of character values.
static <T extends java.lang.Enum> Arbitrary<T>	of(java.lang.Class<T> enumClass) Create an arbitrary for enum values of type T.
static <T> Arbitrary<T>	of(java.util.List<T> values) Create an arbitrary that will randomly choose from a given list of values.
static <T> Arbitrary<T>	of(T... values) Create an arbitrary that will randomly choose from a given array of values.
static <T> Arbitrary<T>	oneOf(Arbitrary<T> first, Arbitrary<T>... rest) Create an arbitrary that will randomly choose between all given arbitraries of the same type T.
static <T> Arbitrary<T>	oneOf(java.util.List<Arbitrary<T>> all) Create an arbitrary that will randomly choose between all given arbitraries of the same type T.
static Arbitrary<java.util.Random>	randoms() Create an arbitrary for Random objects.
static <T> Arbitrary<T>	randomValue(java.util.function.Function<java.util.Random,T> generator) Create an arbitrary that will generate values of type T using a generator function.
static <T> Arbitrary<T>	recursive(java.util.function.Supplier<Arbitrary<T>> base, java.util.function.Function<Arbitrary<T>,Arbitrary<T>> recur, int depth) Create an arbitrary by deterministic recursion.
static <T> Arbitrary<T>	samples(T... samples) Create an arbitrary that will provide the sample values from first to last and then start again at the beginning.
static <M> ActionSequenceArbitrary<M>	sequences(Arbitrary<Action<M>> actionArbitrary) Create an arbitrary to create a sequence of actions.
static ShortArbitrary	shorts() Create an arbitrary that generates values of type Short.
static <T> Arbitrary<java.util.List<T>>	shuffle(java.util.List<T> values) Create an arbitrary that will always generate a list which is a permutation of the values handed to it.
static <T> Arbitrary<java.util.List<T>>	shuffle(T... values) Create an arbitrary that will always generate a list which is a permutation of the values handed to it.
static StringArbitrary	strings() Create an arbitrary that generates values of type String.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

fromGenerator

public static <T> Arbitrary<T> fromGenerator(RandomGenerator<T> generator)

Create an arbitrary of type T from a corresponding generator of type T.

Type Parameters:

T - The type of values to generate

Parameters:

generator - The generator to be used for generating the values

Returns:

a new arbitrary instance

randomValue

public static <T> Arbitrary<T> randomValue(java.util.function.Function<java.util.Random,T> generator)

Create an arbitrary that will generate values of type T using a generator function. The generated values are unshrinkable.

Type Parameters:

T - The type of values to generate

Parameters:

generator - The generator function to be used for generating the values

Returns:

a new arbitrary instance

randoms

public static Arbitrary<java.util.Random> randoms()

Create an arbitrary for Random objects.

Returns:

a new arbitrary instance

of

@SafeVarargs
public static <T> Arbitrary<T> of(T... values)

Create an arbitrary that will randomly choose from a given array of values. A generated value will be shrunk towards the start of the array.

Type Parameters:

T - The type of values to generate

Parameters:

values - The array of values to choose from

Returns:

a new arbitrary instance

of

public static <T> Arbitrary<T> of(java.util.List<T> values)

Create an arbitrary that will randomly choose from a given list of values. A generated value will be shrunk towards the start of the list.

Type Parameters:

T - The type of values to generate

Parameters:

values - The list of values to choose from

Returns:

a new arbitrary instance

of

public static Arbitrary<java.lang.Character> of(char[] values)

Create an arbitrary of character values.

Parameters:

values - The array of characters to choose from.

Returns:

a new arbitrary instance

of

public static <T extends java.lang.Enum> Arbitrary<T> of(java.lang.Class<T> enumClass)

Create an arbitrary for enum values of type T.

Type Parameters:

T - The type of values to generate

Parameters:

enumClass - The enum class.

Returns:

a new arbitrary instance

oneOf

@SafeVarargs
public static <T> Arbitrary<T> oneOf(Arbitrary<T> first,
                                                  Arbitrary<T>... rest)

Create an arbitrary that will randomly choose between all given arbitraries of the same type T.

Type Parameters:

T - The type of values to generate

Parameters:

first - The first arbitrary to choose form

rest - An array of arbitraries to choose from

Returns:

a new arbitrary instance

oneOf

public static <T> Arbitrary<T> oneOf(java.util.List<Arbitrary<T>> all)

Create an arbitrary that will randomly choose between all given arbitraries of the same type T.

Type Parameters:

T - The type of values to generate

Parameters:

all - A list of arbitraries to choose from

Returns:

a new arbitrary instance

frequency

@SafeVarargs
public static <T> Arbitrary<T> frequency(Tuple.Tuple2<java.lang.Integer,T>... frequencies)

Create an arbitrary that will randomly choose between all given values of the same type T. The probability distribution is weighted with the first parameter of the tuple.

Type Parameters:

T - The type of values to generate

Parameters:

frequencies - An array of tuples of which the first parameter gives the weight and the second the value.

Returns:

a new arbitrary instance

frequency

public static <T> Arbitrary<T> frequency(java.util.List<Tuple.Tuple2<java.lang.Integer,T>> frequencies)

Create an arbitrary that will randomly choose between all given values of the same type T. The probability distribution is weighted with the first parameter of the tuple.

Type Parameters:

T - The type of values to generate

Parameters:

frequencies - A list of tuples of which the first parameter gives the weight and the second the value.

Returns:

a new arbitrary instance

frequencyOf

@SafeVarargs
public static <T> Arbitrary<T> frequencyOf(Tuple.Tuple2<java.lang.Integer,Arbitrary<T>>... frequencies)

Create an arbitrary that will randomly choose between all given arbitraries of the same type T. The probability distribution is weighted with the first parameter of the tuple.

Type Parameters:

T - The type of values to generate

Parameters:

frequencies - An array of tuples of which the first parameter gives the weight and the second the arbitrary.

Returns:

a new arbitrary instance

frequencyOf

public static <T> Arbitrary<T> frequencyOf(java.util.List<Tuple.Tuple2<java.lang.Integer,Arbitrary<T>>> frequencies)

Create an arbitrary that will randomly choose between all given arbitraries of the same type T. The probability distribution is weighted with the first parameter of the tuple.

Type Parameters:

T - The type of values to generate

Parameters:

frequencies - A list of tuples of which the first parameter gives the weight and the second the arbitrary.

Returns:

a new arbitrary instance

integers

public static IntegerArbitrary integers()

Create an arbitrary that generates values of type Integer.

Returns:

a new arbitrary instance

longs

public static LongArbitrary longs()

Create an arbitrary that generates values of type Long.

Returns:

a new arbitrary instance

bigIntegers

public static BigIntegerArbitrary bigIntegers()

Create an arbitrary that generates values of type BigInteger.

Returns:

a new arbitrary instance

floats

public static FloatArbitrary floats()

Create an arbitrary that generates values of type Float.

Returns:

a new arbitrary instance

bigDecimals

public static BigDecimalArbitrary bigDecimals()

Create an arbitrary that generates values of type BigDecimal.

Returns:

a new arbitrary instance

doubles

public static DoubleArbitrary doubles()

Create an arbitrary that generates values of type Double.

Returns:

a new arbitrary instance

bytes

public static ByteArbitrary bytes()

Create an arbitrary that generates values of type Byte.

Returns:

a new arbitrary instance

shorts

public static ShortArbitrary shorts()

Create an arbitrary that generates values of type Short.

Returns:

a new arbitrary instance

strings

public static StringArbitrary strings()

Create an arbitrary that generates values of type String.

Returns:

a new arbitrary instance

chars

public static CharacterArbitrary chars()

Create an arbitrary that generates values of type Character.

Returns:

a new arbitrary instance

samples

@SafeVarargs
public static <T> Arbitrary<T> samples(T... samples)

Create an arbitrary that will provide the sample values from first to last and then start again at the beginning. Shrinking of samples is tried towards the start of the samples.

Type Parameters:

T - The type of values to generate

Parameters:

samples - The array of sample values

Returns:

a new arbitrary instance

constant

public static <T> Arbitrary<T> constant(T value)

Create an arbitrary that will always generate the same value.

Type Parameters:

T - The type of values to generate

Parameters:

value - The value to "generate"

Returns:

a new arbitrary instance

create

@API(status=MAINTAINED,
     since="1.1.1")
public static <T> Arbitrary<T> create(java.util.function.Supplier<T> supplier)

Create an arbitrary that will use a supplier to generate a value. The difference to constant(Object) is that the value is freshly generated for each try of a property. For exhaustive shrinking all generated values are supposed to have identical behaviour, i.e. that means that only one value is generated per combination.

Type Parameters:

T - The type of values to generate

Parameters:

supplier - The supplier use to generate a value

Returns:

a new arbitrary instance

shuffle

public static <T> Arbitrary<java.util.List<T>> shuffle(T... values)

Create an arbitrary that will always generate a list which is a permutation of the values handed to it. Permutations will not be shrunk.

Type Parameters:

T - The type of values to generate

Parameters:

values - The values to permute

Returns:

a new arbitrary instance

shuffle

public static <T> Arbitrary<java.util.List<T>> shuffle(java.util.List<T> values)

Create an arbitrary that will always generate a list which is a permutation of the values handed to it. Permutations will not be shrunk.

Type Parameters:

T - The type of values to generate

Parameters:

values - The values to permute

Returns:

a new arbitrary instance

defaultFor

public static <T> Arbitrary<T> defaultFor(java.lang.Class<T> type,
                                          java.lang.Class<?>... typeParameters)

Find a registered arbitrary that will be used to generate values of type T. All default arbitrary providers and all registered arbitrary providers are considered. This is more or less the same mechanism that jqwik uses to find arbitraries for property method parameters.

Type Parameters:

T - The type of values to generate

Parameters:

type - The type of the value to find an arbitrary for

typeParameters - The type parameters if type is a generic type

Returns:

a new arbitrary instance

Throws:

CannotFindArbitraryException - if there is no registered arbitrary provider to serve this type

defaultFor

@API(status=MAINTAINED,
     since="1.1")
public static <T> Arbitrary<T> defaultFor(TypeUsage typeUsage)

Find a registered arbitrary that will be used to generate values of type T. All default arbitrary providers and all registered arbitrary providers are considered. This is more or less the same mechanism that jqwik uses to find arbitraries for property method parameters.

Type Parameters:

T - The type of values to generate

Parameters:

typeUsage - The type of the value to find an arbitrary for

Returns:

a new arbitrary instance

Throws:

CannotFindArbitraryException - if there is no registered arbitrary provider to serve this type

forType

@API(status=EXPERIMENTAL,
     since="1.1")
public static <T> TypeArbitrary<T> forType(java.lang.Class<T> targetType)

Create an arbitrary for type T that will by default use the type's public constructors and public factory methods.

Type Parameters:

T - The type of values to generate

Parameters:

targetType - The class of the type to create an arbitrary for

Returns:

a new arbitrary instance

See Also:

TypeArbitrary

lazy

public static <T> Arbitrary<T> lazy(java.util.function.Supplier<Arbitrary<T>> arbitrarySupplier)

Create an arbitrary that will evaluate arbitrarySupplier as soon as it is used for generating values.

This is useful (and necessary) when arbitrary providing functions use other arbitrary providing functions in a recursive way. Without the use of lazy() this would result in a stack overflow.

Type Parameters:

T - The type of values to generate

Parameters:

arbitrarySupplier - The supplier function being used to generate an arbitrary

Returns:

a new arbitrary instance

recursive

public static <T> Arbitrary<T> recursive(java.util.function.Supplier<Arbitrary<T>> base,
                                         java.util.function.Function<Arbitrary<T>,Arbitrary<T>> recur,
                                         int depth)

Create an arbitrary by deterministic recursion.

This is useful (and necessary) when arbitrary providing functions use other arbitrary providing functions in a recursive way. Without the use of lazy() this would result in a stack overflow.

Type Parameters:

T - The type of values to generate

Parameters:

base - The supplier returning the recursion's base case

recur - The function to extend the base case

depth - The number of times to invoke recursion

Returns:

a new arbitrary instance

sequences

@API(status=MAINTAINED,
     since="1.0")
public static <M> ActionSequenceArbitrary<M> sequences(Arbitrary<Action<M>> actionArbitrary)

Create an arbitrary to create a sequence of actions. Useful for stateful testing.

Type Parameters:

M - The type of actions to generate

Parameters:

actionArbitrary - The arbitrary to generate individual actions.

Returns:

a new arbitrary instance