prometheus/vendor/github.com/google/gofuzz/README.md

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gofuzz
======
gofuzz is a library for populating go objects with random values.
[![GoDoc](https://godoc.org/github.com/google/gofuzz?status.svg)](https://godoc.org/github.com/google/gofuzz)
[![Travis](https://travis-ci.org/google/gofuzz.svg?branch=master)](https://travis-ci.org/google/gofuzz)
This is useful for testing:
* Do your project's objects really serialize/unserialize correctly in all cases?
* Is there an incorrectly formatted object that will cause your project to panic?
Import with ```import "github.com/google/gofuzz"```
You can use it on single variables:
```go
f := fuzz.New()
var myInt int
f.Fuzz(&myInt) // myInt gets a random value.
```
You can use it on maps:
```go
f := fuzz.New().NilChance(0).NumElements(1, 1)
var myMap map[ComplexKeyType]string
f.Fuzz(&myMap) // myMap will have exactly one element.
```
Customize the chance of getting a nil pointer:
```go
f := fuzz.New().NilChance(.5)
var fancyStruct struct {
A, B, C, D *string
}
f.Fuzz(&fancyStruct) // About half the pointers should be set.
```
You can even customize the randomization completely if needed:
```go
type MyEnum string
const (
A MyEnum = "A"
B MyEnum = "B"
)
type MyInfo struct {
Type MyEnum
AInfo *string
BInfo *string
}
f := fuzz.New().NilChance(0).Funcs(
func(e *MyInfo, c fuzz.Continue) {
switch c.Intn(2) {
case 0:
e.Type = A
c.Fuzz(&e.AInfo)
case 1:
e.Type = B
c.Fuzz(&e.BInfo)
}
},
)
var myObject MyInfo
f.Fuzz(&myObject) // Type will correspond to whether A or B info is set.
```
See more examples in ```example_test.go```.
Happy testing!