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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.
func Check(f any, 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(f, g any, 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(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 struct {
CheckError
Out1 []any
Out2 []any
}
A CheckEqualError is the result CheckEqual finding an error.
func (s *CheckEqualError) Error() string
type CheckError struct {
Count int
In []any
}
A CheckError is the result of Check finding an error.
func (s *CheckError) Error() string
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.
// A count of zero implies the default, which is usually 100
// but can be set by the -quickchecks flag.
MaxCountScale float64
// Rand specifies a source of random numbers.
// If nil, a default pseudo-random source will be used.
Rand *rand.Rand
// Values specifies a function to generate a slice of
// arbitrary reflect.Values that are congruent with the
// arguments to the function being tested.
// If nil, 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 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 string
A SetupError is the result of an error in the way that check is being used, independent of the functions being tested.
func (s SetupError) Error() string