Generation of arbitrary case classes / ADTs with scalacheck and shapeless
/**
* Case class representing a canonical Snowplow event.
*
* @see https://github.com/snowplow/snowplow/wiki/canonical-event-model
*/
case class Event(app_id: Option[String],
platform: Option[String],
etl_tstamp: Option[Instant],
collector_tstamp: Instant,
dvce_created_tstamp: Option[Instant],
event: Option[String],
event_id: UUID,
txn_id: Option[Int],
name_tracker: Option[String],
v_tracker: Option[String],
v_collector: String,
v_etl: String,
user_id: Option[String],
user_ipaddress: Option[String],
user_fingerprint: Option[String],
domain_userid: Option[String],
domain_sessionidx: Option[Int],
network_userid: Option[String],
geo_country: Option[String],
geo_region: Option[String],
geo_city: Option[String],
geo_zipcode: Option[String],
geo_latitude: Option[Double],
geo_longitude: Option[Double],
geo_region_name: Option[String],
ip_isp: Option[String],
ip_organization: Option[String],
ip_domain: Option[String],
ip_netspeed: Option[String],
page_url: Option[String],
page_title: Option[String],
page_referrer: Option[String],
page_urlscheme: Option[String],
page_urlhost: Option[String],
page_urlport: Option[Int],
page_urlpath: Option[String],
page_urlquery: Option[String],
page_urlfragment: Option[String],
refr_urlscheme: Option[String],
refr_urlhost: Option[String],
refr_urlport: Option[Int],
refr_urlpath: Option[String],
refr_urlquery: Option[String],
refr_urlfragment: Option[String],
refr_medium: Option[String],
refr_source: Option[String],
refr_term: Option[String],
mkt_medium: Option[String],
mkt_source: Option[String],
mkt_term: Option[String],
mkt_content: Option[String],
mkt_campaign: Option[String],
contexts: Contexts,
se_category: Option[String],
se_action: Option[String],
se_label: Option[String],
se_property: Option[String],
se_value: Option[Double],
unstruct_event: UnstructEvent,
tr_orderid: Option[String],
tr_affiliation: Option[String],
tr_total: Option[Double],
tr_tax: Option[Double],
tr_shipping: Option[Double],
tr_city: Option[String],
tr_state: Option[String],
tr_country: Option[String],
....
any way to circumvent this?
I'm facing the same issue as @hejfelix, while using implicitly[Arbitrary[BigCaseClass]].arbitrary:
Could not write class xxx because it exceeds JVM code size limits. Method inst$macro$135$lzycompute's code too large!
The case class has 130 fields.
Any workaround to solve this issue? Thanks!
What kind of fields does it have? Primitives or other case classes?
It sounds like shapeless is not the problem, and nested case classes are not the problem
So a bit difficult situation
I found a workaround using generics and implicit generators:
// primitive generators
implicit def stringGen(implicit arbString: Arbitrary[String]): Gen[String] = arbString.arbitrary
implicit def intGen(implicit arbInt: Arbitrary[Int]): Gen[Int] = arbInt.arbitrary
// hlist generator
implicit def hnilGen: Gen[HNil] = Gen.const(HNil)
implicit def hlistGen[H, T <: HList](implicit headGen: Gen[H], tailGen: Gen[T]) = headGen.flatMap(head => tailGen.map(tail => head :: tail))
// case class generator
implicit def caseClassGen[T, L <: HList](implicit generic: Generic.Aux[T, L], lGen: Gen[L]): Gen[T] = lGen.map(generic.from)
def generator[A](implicit gen: Gen[A]): Gen[A] = genThen you can generate arbitrary big case classes like this:
implicit val generic = Generic[YourBigCaseClass]
val gen = generator[YourBigCaseClass]
val sample = Gen.nonEmptyListOf(gen).sample.getI hope that helps anyone facing this limitation.
I'm trying to write a test using ScalaTest's
ShrinkLowPriority trait but it seems to conflict with the internals of scalacheck-shapeless. I get Error:(27, 88) ambiguous implicit values:
both method derivedShrink in trait DerivedInstances of type [T](implicit ev: shapeless.LowPriority.Ignoring[String("shrinkAny")], implicit underlying: shapeless.Strict[org.scalacheck.derive.MkShrink[T]])org.scalacheck.Shrink[T]
and method shrinkAny in trait ShrinkLowPriority of type [T]=> org.scalacheck.Shrink[T]
match expected type ...
How can I disable shrinking in my own tests?
Looking at the source there is a
implicit def derivedShrink[T]
(implicit
ev: LowPriority.Ignoring[Witness.`"shrinkAny"`.T],
underlying: Strict[MkShrink[T]]
): Shrink[T] =
underlying.value.shrinkBut I don't understand what it does.
4 replies
Hello, can scalacheck-shapeless work with case classes with in turn have fields like Instant / Date / Curency / scala enumeratum, if there are "manual" arbitraries provided for these ?
I can't seem to make it work
the closest i get is to a
scala.UninitializedFieldError: Uninitialized fieldedit: it works just have to have all the implicit imports near
import org.scalacheck.ScalacheckShapeless._
I am experiencing an issue with the library that is described in this ticket: alexarchambault/scalacheck-shapeless#46
Will this be fixed in 1.15 or is not going to be fixed?
I have a case class and one of the fields is an Option of a type which is an ADT (a sealed trait with sum types) but when I get runtime exceptions when it tries to generate instances for it
If I take out the Option with that sealed trait all is fine
?