Test.StrongCheck

data Result

The result of a property test.

Constructors

• Success
• Failed String

Instances

• Eq Result
• Ord Result
• Show Result
• Semigroup Result
• Monoid Result
• Testable Result

class Testable prop  where

A class for types that can be treated as a property test result.

Members

• test :: prop -> Gen Result

Instances

• Testable Boolean
• Testable Result
• (Arbitrary t, Testable prop) => Testable (t -> prop)
• (Testable prop) => Testable (GenT (Free (Function Unit)) prop)

quickCheck :: forall prop. Testable prop => prop -> Effect Unit

Checks the proposition for 100 random values.

quickCheck' :: forall prop. Testable prop => Int -> prop -> Effect Unit

Checks the proposition for the specified number of random values.

quickCheckWithSeed :: forall prop. Testable prop => Seed -> Int -> prop -> Effect Unit

Checks the proposition for the specified number of random values, starting with a specific seed.

quickCheckPure :: forall prop. Testable prop => Int -> Seed -> prop -> Array (Tuple Seed Result)

Checks the proposition for the specified number of random values in a pure setting, returning an array of results.

smallCheck :: forall prop. Testable prop => prop -> Effect Unit

Exhaustively checks the proposition for all possible values. Assumes the generator is a finite generator.

smallCheckPure :: forall prop. Testable prop => Seed -> prop -> Array (Tuple Seed Result)

Exhaustively checks the proposition for all possible values in a pure setting, returning an array of results. Assumes the generator is a finite generator.

statCheck :: forall prop. Testable prop => Number -> prop -> Effect Unit

Checks that the proposition has a certain probability of being true for arbitrary values.

statCheckPure :: forall prop. Testable prop => Seed -> Number -> prop -> Result

Checks that the proposition has a certain probability of being true for arbitrary values in a pure setting, returning a result.

assert :: forall prop. Testable prop => prop -> Effect Unit

Checks that the specified proposition holds. Useful for unit tests.

assertEq :: forall a. Eq a => Show a => a -> a -> Result

Asserts that two values are equal, resulting in a Failure if they are not, with a message showing the values involved.

Operator alias for Test.StrongCheck.assertEq (non-associative / precedence 2)

assertNotEq :: forall a. Eq a => Show a => a -> a -> Result

Asserts that two values are not equal, resulting in a Failure if they are, with a message showing the values involved.

Operator alias for Test.StrongCheck.assertNotEq (non-associative / precedence 2)

annotate :: Boolean -> String -> Result

Converts a Boolean into a Result by lifting a message into Failed when the boolean is false.

Operator alias for Test.StrongCheck.annotate (non-associative / precedence 1)

class Arbitrary t  where

The Arbitrary class represents those types whose values can be randomly-generated.

arbitrary uses the Gen monad to express a random generator for the type t. Combinators in the Test.StrongCheck.Gen module can be used to construct random generators.

Members

• arbitrary :: Gen t

Instances

• Arbitrary Boolean
• Arbitrary Number
• Arbitrary Int
• Arbitrary String
• Arbitrary Char
• Arbitrary Unit
• Arbitrary Ordering
• (Arbitrary a) => Arbitrary (Array a)
• (Coarbitrary a, Arbitrary b) => Arbitrary (a -> b)
• (Arbitrary a, Arbitrary b) => Arbitrary (Tuple a b)
• (Arbitrary a) => Arbitrary (Maybe a)
• (Arbitrary a, Arbitrary b) => Arbitrary (Either a b)
• (Arbitrary a) => Arbitrary (List a)
• (Arbitrary a) => Arbitrary (Identity a)
• (Arbitrary a) => Arbitrary (Lazy a)

class Coarbitrary t  where

The Coarbitrary class represents types which appear on the left of an Arbitrary function arrow.

To construct an Arbitrary instance for the type a -> b, we need to use the input of type a to perturb a random generator for b. This is the role of the coarbitrary function.

Coarbitrary instances can be written using the perturbGen function.

Members

• coarbitrary :: forall r. t -> Gen r -> Gen r

Instances

• Coarbitrary Boolean
• Coarbitrary Number
• Coarbitrary Int
• Coarbitrary String
• Coarbitrary Char
• Coarbitrary Unit
• Coarbitrary Ordering
• (Coarbitrary a) => Coarbitrary (Array a)
• (Arbitrary a, Coarbitrary b) => Coarbitrary (a -> b)
• (Coarbitrary a, Coarbitrary b) => Coarbitrary (Tuple a b)
• (Coarbitrary a) => Coarbitrary (Maybe a)
• (Coarbitrary a, Coarbitrary b) => Coarbitrary (Either a b)
• (Coarbitrary a) => Coarbitrary (List a)
• (Coarbitrary a) => Coarbitrary (Identity a)
• (Coarbitrary a) => Coarbitrary (Lazy a)

newtype Seed

A seed for the linear congruential generator. We omit a Semiring instance because there is no zero value, as 0 is not an acceptable seed for the generator.

Instances

• Show Seed
• Eq Seed

mkSeed :: Int -> Seed