Built-in generators

Kwik provide a collection of generators to satisfy a wide variety of uses-cases.

They are all available as extension functions on Generator.Companion so that we can find them easily and invoke them like this:

val generator = Generator.ints()

Primitives

Generator.ints(min = Int.MIN_VALUE, max = Int.MAX_VALUE)

Generate integers. Includes the samples: 0, 1, -1, min and max.

Note that there are also positiveInts, naturalInts, negativeInts and nonZeroInts alternatives

Generator.longs(min = Long.MIN_VALUE, max = Long.MAX_VALUE)

Generate longs. Includes the samples: 0, 1, -1, min and max.

Note that there are also positiveLongs, naturalLongs, negativeLongs and nonZeroLongs alternatives

Generator.floats(min = -Float.MAX_VALUE, max = Float.MAX_VALUE)

Generate longs. Includes the samples: 0.0, 1.0, -1.0, min and max.

Note that NaN, POSITIVE_INFINITY and POSITIVE_INFINITY are not generated. To test theses, we can use withSamples() or withNaN()

Example: Generator.floats().withNaN().withSamples(Float.POSITIVE_INFINITY)

Note that there are also positiveFloats, negativeFloats and nonZeroFloats alternatives

Generator.doubles(min = -Double.MAX_VALUE, max = Double.MAX_VALUE)

Generate doubles. Includes the samples: 0.0, 1.0, -1.0, min and max.

Note that NaN, POSITIVE_INFINITY and POSITIVE_INFINITY are not generated. To test theses, we can use withSamples() or withNaN()

Example: Generator.doubles().withNaN().withSamples(Double.POSITIVE_INFINITY)

Note that there are also positiveDoubles, negativeDoubles and nonZeroDoubles alternatives

Generator.booleans()

Generate booleans

Text

Generator.characters(charset = CharSets.printable, exclude = emptySet())

Generate strings. Use the parameter charset and exclude to customize the characters which can be used.

Generation includes space (’ ‘) as a sample.

Note

CharSets provide few common set of characters such as alpha, alphaNumeric and others

It is there to help quickly configure the Character generator.

By default, it will generate any printable characters.

Generator.strings(minLength = 0, maxLength = 50, charGenerator = Generator.characters())

Generate strings. Use the parameter charGenerator to provide a character generator which is used to make the string.

Generation includes empty (“”) string as a sample.

Collections

Generator.lists(elementGen = Generator.default(), minSize = 0, maxSize = 50)

Generate lists. elementGen can be used to define the generator of the elements.

Generation include empty and singleton lists as samples

Note that there is also a nonEmptyLists alternative

Generator.sets(elementGen = Generator.default(), minSize = 0, maxSize = 50)

Generate sets. elementGen can be used to define the generator of the elements.

Generation include empty and singleton sets as samples

Will fail in it takes too much iteration to reach the minSize (so make sure the element generator can generate enough different values)

Note that there is also a nonEmptySets alternative

Generator.maps(keyGen = Generator.default(), valueGen = Generator.default(), minSize = 0, maxSize = 50)

Generate sets. keyGen can be used to define the generator of the elements.

Generation include empty and singleton maps as samples

Will fail in it takes too much iteration to reach the minSize (so make sure the element generator can generate enough different values)

Note that there is also a nonEmptyMaps alternative

Sequences

Generator.sequences(elementGen = Generator.default(), minSize = 0, maxSize = 50)

Generate sequences. elementGen can be used to define the generator of the elements.

Generation include empty and singleton sequences as samples

Note that there is also a nonEmptySequences alternative

Ranges

Generator.ranges(elementGen)

Generate ranges. elementGen can be used to define the generator of the elements.

Generator.intRanges(elementGen = Generator.ints())

Generates ClosedRanged<Int>. Includes empty and singleton ranges as samples

Generator.longRanges(elementGen = Generator.longs())

Generates ClosedRanged<Long>. Includes empty and singleton ranges as samples

Generator.charRanges(elementGen = Generator.characters())

Generates ClosedRanged<Char>. Includes empty and singleton ranges as samples

Enums

Generator.enum<T>()

Create a generator for the given enum type T.

The enum must contains at least one enumeration.

Java

Generator.uuids()

Create a generator for UUID

Java Time API

Generator.instants(min: Instant.MIN, max: Instant.MAX)

Generates Instants (with nano seconds), includes the samples: Instant.EPOCH (1970-01-01T00:00:00.000Z), min and max

Generator.durations(min, max)

Generates Durations (with nano seconds), Includes the samples: Duration.ZERO, min and max

Generator.localTimes(min: LocalTime.MIN, max: LocalTime.MAX)

Generates LocalTimes (with nano seconds), Includes the samples: LocalTime.NOON, min and max

Generator.localDates(min: LocalDate.MIN, max: LocalDate.MAX)

Generates LocalDates, includes the samples: LocalDate.EPOCH (1970-01-01), min and max

Generator.localDateTimes(min: LocalDateTime.MIN, max: LocalDateTime.MAX)

Generates LocalDateTimes, includes the samples: LocalDate.EPOCH.atStartOfDay (1970-01-01T00:00:00.000Z), min and max