scalatestCoreDotty/org.scalatest/org.scalatest.prop/Configuration

Configuration

org.scalatest.prop.Configuration

See theConfiguration companion object

Trait providing methods and classes used to configure property checks provided by the the forAll methods of trait GeneratorDrivenPropertyChecks (for ScalaTest-style property checks) and the check methods of trait Checkers (for ScalaCheck-style property checks).

Attributes

Companion: object
Graph
Supertypes: class Object

trait Matchable

class Any
Known subtypes: object Configuration.type

trait GeneratorDrivenPropertyChecks

object GeneratorDrivenPropertyChecks.type

trait PropertyChecks

object PropertyChecks.type

Members list

Type members

Classlikes

A PropertyCheckConfigParam that specifies how many generated values may be discarded, as a multiple of the successful attempts, before the property check is considered to be org.scalatest.prop.PropertyCheckResult.Exhausted.

In GeneratorDrivenPropertyChecks, a property evaluation is discarded if it throws DiscardedEvaluationException, which is produced by a whenever clause that evaluates to false. For example, consider this ScalaTest property check:

// forAll defined in GeneratorDrivenPropertyChecks
forAll { (n: Int) =>
 whenever (n > 0) {
   doubleIt(n) should equal (n * 2)
 }
}

In the above code, whenever a non-positive n is passed, the property function will complete abruptly with DiscardedEvaluationException.

Similarly, in Checkers, a property evaluation is discarded if the expression to the left of ScalaCheck's ==> operator is false. Here's an example:

// forAll defined in Checkers
forAll { (n: Int) =>
 (n > 0) ==> doubleIt(n) == (n * 2)
}

For either kind of property check, MaxDiscardedFactor indicates the maximum fraction of total tests that may be discarded, relative to the number of successful tests. For example, if this is set to 4.0, and you are running 100 tests, it may discard up to 400 tries before considering the test to be org.scalatest.prop.PropertyCheckResult.Exhausted.

Value parameters

value: the permitted number of discarded tests, as a multiple of successful ones.

Attributes

Supertypes: class PropertyCheckConfigParam

trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all

A PropertyCheckConfigParam that specifies the minimum size parameter to provide to ScalaCheck, which it will use when generating objects for which size matters (such as strings or lists).

Attributes

Supertypes: class PropertyCheckConfigParam

trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all

A PropertyCheckConfigParam that specifies the minimum number of successful property evaluations required for the property to pass.

Once this many evaluations have passed, the property will return PropertyCheckResult.Success.

Attributes

Supertypes: class PropertyCheckConfigParam

trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all

Abstract class defining a family of configuration parameters for property checks.

The subclasses of this abstract class are used to pass configuration information to the forAll methods of traits PropertyChecks (for ScalaTest-style property checks) and Checkers(for ScalaCheck-style property checks).

Attributes

Supertypes: trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all
Known subtypes: class MaxDiscardedFactor

class MinSize

class MinSuccessful

class SizeRange

class Workers

Describes the configuration to use when evaluating a property.

Value parameters

maxDiscardedFactor: how many generated values may be discarded, as a multiple of the successful attempts, before the property check is considered to be org.scalatest.prop.PropertyCheckResult.Exhausted; see MaxDiscardedFactor
minSize: the minimum size parameter to provide to ScalaCheck, which it will use when generating objects for which size matters (such as strings or lists); see MinSize
minSuccessful: the minimum number of successful property evaluations required for the property to pass; see MinSuccessful
sizeRange: the maximum size parameter to provide to ScalaCheck, which it will use when generating objects for which size matters (such as strings or lists); see SizeRange
workers: number of worker threads to use when evaluating a property; see Workers

Attributes

Companion: object
Supertypes: trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all

Internal utility functions for configuration management.

Attributes

Companion: class
Supertypes: trait Product

trait Mirror

class Object

trait Matchable

class Any
Self type: PropertyCheckConfiguration.type

A PropertyCheckConfigParam that (with minSize) specifies the maximum size parameter to provide to ScalaCheck, which it will use when generating objects for which size matters (such as strings or lists).

Note that the size range is added to minSize in order to calculate the maximum size passed to ScalaCheck. Using a range allows compile-time checking of a non-negative number being specified.

Attributes

Supertypes: class PropertyCheckConfigParam

trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all

A PropertyCheckConfigParam that specifies the number of worker threads to use when evaluating a property.

Property evaluation runs on a single thread by default, but may run multiple threads if desired. If so, the evaluation will generally run faster. However, be careful not to use this if there is any risk of deadlocks, race conditions, or other hazards of multi-threaded code in evaluating this property or the code under test.

Attributes

Supertypes: class PropertyCheckConfigParam

trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all

Value members

Concrete methods

Given some optional PropertyCheckConfigParams and a PropertyCheckConfiguration, compute the resulting Configuration.Parameter.

This function deals with resolving the various forms of these configuration values, into a consistent form suitable for using in properties.

Duplicate PropertyCheckConfigParam entries are not permitted in the configParams list.

TODO: should this function be public? It feels like an internal implementation detail -- I think it should be private.

Value parameters

c: a configuration object, describing how to run property evaluations
configParams: optionally, some parameters that differ from the provided c

Attributes

Returns: a fully-set-up Configuration.Parameter object, ready to evaluate properties with.

Returns a MaxDiscardedFactor property check configuration parameter containing the passed value, which specifies the factor of discarded property evaluations allowed during property evaluation.

Attributes

Returns a MinSize property check configuration parameter containing the passed value, which specifies the minimum size parameter to provide to ScalaCheck, which it will use when generating objects for which size matters (such as strings or lists).

Attributes

Returns a MinSuccessful property check configuration parameter containing the passed value, which specifies the minimum number of successful property evaluations required for the property to pass.

Attributes

Returns a SizeRange property check configuration parameter containing the passed value, that (with minSize) specifies the maximum size parameter to provide to ScalaCheck, which it will use when generating objects for which size matters (such as strings or lists).

Note that the size range is added to minSize in order to calculate the maximum size passed to ScalaCheck. Using a range allows compile-time checking of a non-negative number being specified.

Attributes

Returns a Workers property check configuration parameter containing the passed value, which specifies the number of worker threads to use when evaluating a property.

Attributes

Implicits

Implicit PropertyCheckConfig value providing default configuration values.

Attributes

In this article

Generated with