Supported Types¶

Some resolves common Kotlin and Java types with zero configuration. Nullable variants (T?) are supported everywhere — NullableStrategy controls whether null is emitted.

For types not listed here, register a custom factory or ship a custom resolver.

Reference¶

Type	Usage	Notes
Primitives
`String`	`some<String>()`	See StringStrategy
`Int`	`some<Int>()`
`Long`	`some<Long>()`
`Double`	`some<Double>()`
`Float`	`some<Float>()`	See FloatStrategy
`Boolean`	`some<Boolean>()`
`Char`	`some<Char>()`
`Byte`	`some<Byte>()`
`Short`	`some<Short>()`
`Number`	`some<Number>()`	Resolves to a random concrete numeric type (`Int`, `Long`, `Double`, `Float`, or `Short`)
Standard Library
`kotlin.uuid.Uuid`	`some<Uuid>()`	Requires `@OptIn(ExperimentalUuidApi::class)`
`java.util.UUID`	`some<UUID>()`
`java.util.Optional<T>`	`some<Optional<String>>()`	See NullableStrategy
`kotlin.time.Duration`	`some<Duration>()`
`java.time.Duration`	`some<java.time.Duration>()`
`kotlin.time.Instant`	`some<Instant>()`
`java.time.Instant`	`some<java.time.Instant>()`
`java.math.BigDecimal`	`some<BigDecimal>()`
`java.math.BigInteger`	`some<BigInteger>()`
`java.time.LocalDate`	`some<LocalDate>()`
`java.time.LocalDateTime`	`some<LocalDateTime>()`
`java.time.ZonedDateTime`	`some<ZonedDateTime>()`
Collections
`List<T>`	`some<List<String>>()`	See CollectionStrategy
`MutableList<T>`	`some<MutableList<Int>>()`
`Set<T>`	`some<Set<String>>()`
`MutableSet<T>`	`some<MutableSet<String>>()`
`Map<K, V>`	`some<Map<String, Int>>()`
`MutableMap<K, V>`	`some<MutableMap<String, Int>>()`
`Array<T>`	`some<Array<String>>()`
Kotlin constructs
Data classes	`some<MyDataClass>()`
Sealed classes/interfaces	`some<MySealed>()`	Random subclass, including `object` variants
Enums	`some<MyEnum>()`	Random constant
Value classes	`some<MyValue>()`	Unwraps to the underlying type
Object singletons	`some<MyObject>()`	Returns the singleton instance
Generics	`some<Box<User>>()`	Recursively resolves type arguments

Custom types¶

Classes that don't have a primary constructor, require special construction logic, or are third-party types need a custom type factory:

data class Email(val value: String)

someSetup {
    factory(Email::class) { Email("user${random.nextInt(1000)}@example.com") }
}

See Type and Property Factories for more.

For library authors or application developers who want to bundle resolver logic for a custom type, see Custom Resolvers to learn about ResolverProvider.