package quick

import “testing/quick”

Package quick implements utility functions to help with black box testing.

The testing/quick package is frozen and is not accepting new features.

Index func Check(f interface{}, config *Config) error func CheckEqual(f, g interface{}, config *Config) error func Value(t reflect.Type, rand *rand.Rand) (value reflect.Value, ok bool) type CheckEqualError func (s *CheckEqualError) Error() string type CheckError func (s *CheckError) Error() string type Config type Generator type SetupError func (s SetupError) Error() string Package Files

quick.go

func Check ❖ func Check(f interface{}, config *Config) error Check looks for an input to f, any function that returns bool, such that f returns false. It calls f repeatedly, with arbitrary values for each argument. If f returns false on a given input, Check returns that input as a *CheckError. For example:

func TestOddMultipleOfThree(t *testing.T) { f := func(x int) bool { y := OddMultipleOfThree(x) return y%2 == 1 && y%3 == 0 } if err := quick.Check(f, nil); err != nil { t.Error(err) } } func CheckEqual ❖ func CheckEqual(f, g interface{}, config *Config) error CheckEqual looks for an input on which f and g return different results. It calls f and g repeatedly with arbitrary values for each argument. If f and g return different answers, CheckEqual returns a *CheckEqualError describing the input and the outputs.

func Value ❖ func Value(t reflect.Type, rand *rand.Rand) (value reflect.Value, ok bool) Value returns an arbitrary value of the given type. If the type implements the Generator interface, that will be used. Note: To create arbitrary values for structs, all the fields must be exported.

type CheckEqualError ❖ type CheckEqualError struct { CheckError Out1 []interface{} Out2 []interface{} } A CheckEqualError is the result CheckEqual finding an error.

func (*CheckEqualError) Error

❖ func (s *CheckEqualError) Error() string type CheckError ❖ type CheckError struct { Count int In []interface{} } A CheckError is the result of Check finding an error.

func (*CheckError) Error

❖ func (s *CheckError) Error() string type Config ❖ type Config struct { // MaxCount sets the maximum number of iterations. If zero, // MaxCountScale is used. MaxCount int // MaxCountScale is a non-negative scale factor applied to the default // maximum. If zero, the default is unchanged. MaxCountScale float64 // If non-nil, rand is a source of random numbers. Otherwise a default // pseudo-random source will be used. Rand *rand.Rand // If non-nil, the Values function generates a slice of arbitrary // reflect.Values that are congruent with the arguments to the function // being tested. Otherwise, the top-level Value function is used // to generate them. Values func([]reflect.Value, *rand.Rand) } A Config structure contains options for running a test.

type Generator ❖ type Generator interface { // Generate returns a random instance of the type on which it is a // method using the size as a size hint. Generate(rand *rand.Rand, size int) reflect.Value } A Generator can generate random values of its own type.

type SetupError ❖ type SetupError string A SetupError is the result of an error in the way that check is being used, independent of the functions being tested.

func (SetupError) Error

❖ func (s SetupError) Error() string