A PropertyCheckConfigParam
that specifies the maximum number of discarded
property evaluations allowed during property evaluation.
A PropertyCheckConfigParam
that 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).
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).
A PropertyCheckConfigParam
that specifies the minimum number of successful
property evaluations required for the property to pass.
Configuration object for property checks.
Abstract class defining a family of configuration parameters for property checks.
A PropertyCheckConfigParam
that specifies the number of worker threads
to use when evaluating a property.
o != arg0
is the same as !(o == (arg0))
.
o != arg0
is the same as !(o == (arg0))
.
the object to compare against this object for dis-equality.
false
if the receiver object is equivalent to the argument; true
otherwise.
o == arg0
is the same as if (o eq null) arg0 eq null else o.equals(arg0)
.
o == arg0
is the same as if (o eq null) arg0 eq null else o.equals(arg0)
.
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
o == arg0
is the same as o.equals(arg0)
.
o == arg0
is the same as o.equals(arg0)
.
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
This method is used to cast the receiver object to be of type T0
.
This method is used to cast the receiver object to be of type T0
.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression1.asInstanceOf[String]
will throw a ClassCastException
at runtime, while the expressionList(1).asInstanceOf[List[String]]
will not. In the latter example, because the type argument is erased as
part of compilation it is not possible to check whether the contents of the list are of the requested typed.
the receiver object.
Check a property.
Check a property.
the property to check
Check a property with the given testing parameters.
Check a property with the given testing parameters.
the property to check
the test parameters
Convert the passed 6-arg function into a property, and check it.
Convert the passed 6-arg function into a property, and check it.
the function to be converted into a property and checked
Convert the passed 5-arg function into a property, and check it.
Convert the passed 5-arg function into a property, and check it.
the function to be converted into a property and checked
Convert the passed 4-arg function into a property, and check it.
Convert the passed 4-arg function into a property, and check it.
the function to be converted into a property and checked
Convert the passed 3-arg function into a property, and check it.
Convert the passed 3-arg function into a property, and check it.
the function to be converted into a property and checked
Convert the passed 2-arg function into a property, and check it.
Convert the passed 2-arg function into a property, and check it.
the function to be converted into a property and checked
Convert the passed 1-arg function into a property, and check it.
Convert the passed 1-arg function into a property, and check it.
the function to be converted into a property and checked
This method creates and returns a copy of the receiver object.
This method creates and returns a copy of the receiver object.
The default implementation of the clone
method is platform dependent.
a copy of the receiver object.
This method is used to test whether the argument (arg0
) is a reference to the
receiver object (this
).
This method is used to test whether the argument (arg0
) is a reference to the
receiver object (this
).
The eq
method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on
non-null instances of AnyRef
:
* It is reflexive: for any non-null instance x
of type AnyRef
, x.eq(x)
returns true
.
* It is symmetric: for any non-null instances x
and y
of type AnyRef
, x.eq(y)
returns true
if and
only if y.eq(x)
returns true
.
* It is transitive: for any non-null instances x
, y
, and z
of type AnyRef
if x.eq(y)
returns true
and y.eq(z)
returns true
, then x.eq(z)
returns true
.
Additionally, the eq
method has three other properties.
* It is consistent: for any non-null instances x
and y
of type AnyRef
, multiple invocations of
x.eq(y)
consistently returns true
or consistently returns false
.
* For any non-null instance x
of type AnyRef
, x.eq(null)
and null.eq(x)
returns false
.
* null.eq(null)
returns true
.
When overriding the equals
or hashCode
methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they
should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).
the object to compare against this object for reference equality.
true
if the argument is a reference to the receiver object; false
otherwise.
This method is used to compare the receiver object (this
) with the argument object (arg0
) for equivalence.
This method is used to compare the receiver object (this
) with the argument object (arg0
) for equivalence.
The default implementations of this method is an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence
relation]:
* It is reflexive: for any instance x
of type Any
, x.equals(x)
should return true
.
* It is symmetric: for any instances x
and y
of type Any
, x.equals(y)
should return true
if and
only if y.equals(x)
returns true
.
* It is transitive: for any instances x
, y
, and z
of type AnyRef
if x.equals(y)
returns true
and
y.equals(z)
returns true
, then x.equals(z)
should return true
.
If you override this method, you should verify that your implementation remains an equivalence relation.
Additionally, when overriding this method it is often necessary to override hashCode
to ensure that objects
that are "equal" (o1.equals(o2)
returns true
) hash to the same
scala.Int
(o1.hashCode.equals(o2.hashCode)
).
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
The details of when and if the finalize
method are invoked, as well as the interaction between finalize
and non-local returns and exceptions, are all platform dependent.
Implicit PropertyCheckConfig
value providing default configuration values.
Implicit PropertyCheckConfig
value providing default configuration values.
Returns a representation that corresponds to the dynamic class of the receiver object.
Returns a representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
Returns a hash code value for the object.
Returns a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)
) yet
not be equal (o1.equals(o2)
returns false
). A degenerate implementation could always return 0
.
However, it is required that if two objects are equal (o1.equals(o2)
returns true
) that they have
identical hash codes (o1.hashCode.equals(o2.hashCode)
). Therefore, when overriding this method, be sure
to verify that the behavior is consistent with the equals
method.
the hash code value for the object.
This method is used to test whether the dynamic type of the receiver object is T0
.
This method is used to test whether the dynamic type of the receiver object is T0
.
Note that the test result of the test is modulo Scala's erasure semantics. Therefore the expression1.isInstanceOf[String]
will return false
, while the expression List(1).isInstanceOf[List[String]]
will
return true
. In the latter example, because the type argument is erased as part of compilation it is not
possible to check whether the contents of the list are of the requested typed.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
Returns a MaxDiscarded
property check configuration parameter containing the passed value, which specifies the maximum number of discarded
property evaluations allowed during property evaluation.
Returns a MaxDiscarded
property check configuration parameter containing the passed value, which specifies the maximum number of discarded
property evaluations allowed during property evaluation.
Returns a MaxSize
property check configuration parameter containing the passed value, which 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).
Returns a MaxSize
property check configuration parameter containing the passed value, which 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 maximum size should be greater than or equal to the minimum size. This requirement is
enforced by the PropertyCheckConfig
constructor and the forAll
methods of
traits PropertyChecks
and Checkers
. In other words, it is enforced at the point
both a maximum and minimum size are provided together.
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).
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).
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.
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.
o.ne(arg0)
is the same as !(o.eq(arg0))
.
o.ne(arg0)
is the same as !(o.eq(arg0))
.
the object to compare against this object for reference dis-equality.
false
if the argument is not a reference to the receiver object; true
otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Returns a string representation of the object.
Returns a string representation of the object.
The default representation is platform dependent.
a string representation of the object.
Returns a Workers
property check configuration parameter containing the passed value, which specifies the number of worker threads
to use when evaluating a property.
Returns a Workers
property check configuration parameter containing the passed value, which specifies the number of worker threads
to use when evaluating a property.
Trait that contains several “check” methods that perform ScalaCheck property checks. If ScalaCheck finds a test case for which a property doesn't hold, the problem will be reported as a ScalaTest test failure.
To use ScalaCheck, you specify properties and, in some cases, generators that generate test data. You need not always create generators, because ScalaCheck provides many default generators for you that can be used in many situations. ScalaCheck will use the generators to generate test data and with that data run tests that check that the property holds. Property-based tests can, therefore, give you a lot more testing for a lot less code than assertion-based tests. Here's an example of using ScalaCheck from a
JUnitSuite
:The
check
method, defined inCheckers
, makes it easy to write property-based tests inside ScalaTest, JUnit, and TestNG test suites. This example specifies a property thatList
's:::
method should obey. ScalaCheck properties are expressed as function values that take the required test data as parameters. ScalaCheck will generate test data using generators and repeatedly pass generated data to the function. In this case, the test data is composed of integer lists nameda
andb
. Inside the body of the function, you see:The property in this case is a
Boolean
expression that will yield true if the size of the concatenated list is equal to the size of each individual list added together. With this small amount of code, ScalaCheck will generate possibly hundreds of value pairs fora
andb
and test each pair, looking for a pair of integers for which the property doesn't hold. If the property holds true for every value ScalaCheck tries,check
returns normally. Otherwise,check
will complete abruptly with aTestFailedException
that contains information about the failure, including the values that cause the property to be false.For more information on using ScalaCheck properties, see the documentation for ScalaCheck, which is available from http://code.google.com/p/scalacheck/.
To execute a suite that mixes in
Checkers
with ScalaTest'sRunner
, you must include ScalaCheck's jar file on the class path or runpath.Property check configuration
The property checks performed by the
check
methods of this trait can be flexibly configured via the services provided by supertraitConfiguration
. The five configuration parameters for property checks along with their default values and meanings are described in the following table:The
check
methods of traitCheckers
each take aPropertyCheckConfig
object as an implicit parameter. This object provides values for each of the five configuration parameters. TraitConfiguration
provides an implicitval
namedgeneratorDrivenConfig
with each configuration parameter set to its default value. If you want to set one or more configuration parameters to a different value for all property checks in a suite you can override this val (or hide it, for example, if you are importing the members of theCheckers
companion object rather than mixing in the trait.) For example, if you want all parameters at their defaults except forminSize
andmaxSize
, you can overridegeneratorDrivenConfig
, like this:Or, if hide it by declaring a variable of the same name in whatever scope you want the changed values to be in effect:
In addition to taking a
PropertyCheckConfig
object as an implicit parameter, thecheck
methods of traitCheckers
also take a variable length argument list ofPropertyCheckConfigParam
objects that you can use to override the values provided by the implicitPropertyCheckConfig
for a singlecheck
invocation. You place these configuration settings after the property or property function, For example, if you want to setminSuccessful
to 500 for just one particularcheck
invocation, you can do so like this:This invocation of
check
will use 500 forminSuccessful
and whatever values are specified by the implicitly passedPropertyCheckConfig
object for the other configuration parameters. If you want to set multiple configuration parameters in this way, just list them separated by commas:The previous configuration approach works the same in
Checkers
as it does inGeneratorDrivenPropertyChecks
. TraitCheckers
also provides onecheck
method that takes anorg.scalacheck.Test.Params
object, in case you want to configure ScalaCheck that way.For more information, see the documentation for supertrait
Configuration
.