github.com/gophercloud/gophercloud@v1.11.0/internal/acceptance/tools/tools.go (about)

     1  package tools
     2  
     3  import (
     4  	"crypto/rand"
     5  	"encoding/json"
     6  	"errors"
     7  	mrand "math/rand"
     8  	"testing"
     9  	"time"
    10  )
    11  
    12  // ErrTimeout is returned if WaitFor/WaitForTimeout take longer than their timeout duration.
    13  var ErrTimeout = errors.New("Timed out")
    14  
    15  // WaitFor uses WaitForTimeout to poll a predicate function once per second to
    16  // wait for a certain state to arrive, with a default timeout of 300 seconds.
    17  func WaitFor(predicate func() (bool, error)) error {
    18  	return WaitForTimeout(predicate, 600*time.Second)
    19  }
    20  
    21  // WaitForTimeout polls a predicate function once per second to wait for a
    22  // certain state to arrive, or until the given timeout is reached.
    23  func WaitForTimeout(predicate func() (bool, error), timeout time.Duration) error {
    24  	startTime := time.Now()
    25  	for time.Since(startTime) < timeout {
    26  		time.Sleep(2 * time.Second)
    27  
    28  		satisfied, err := predicate()
    29  		if err != nil {
    30  			return err
    31  		}
    32  		if satisfied {
    33  			return nil
    34  		}
    35  	}
    36  	return ErrTimeout
    37  }
    38  
    39  // MakeNewPassword generates a new string that's guaranteed to be different than the given one.
    40  func MakeNewPassword(oldPass string) string {
    41  	randomPassword := RandomString("", 16)
    42  	for randomPassword == oldPass {
    43  		randomPassword = RandomString("", 16)
    44  	}
    45  	return randomPassword
    46  }
    47  
    48  // RandomString generates a string of given length, but random content.
    49  // All content will be within the ASCII graphic character set.
    50  // (Implementation from Even Shaw's contribution on
    51  // http://stackoverflow.com/questions/12771930/what-is-the-fastest-way-to-generate-a-long-random-string-in-go).
    52  func RandomString(prefix string, n int) string {
    53  	const alphanum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
    54  	var bytes = make([]byte, n)
    55  	rand.Read(bytes)
    56  	for i, b := range bytes {
    57  		bytes[i] = alphanum[b%byte(len(alphanum))]
    58  	}
    59  	return prefix + string(bytes)
    60  }
    61  
    62  // RandomInt will return a random integer between a specified range.
    63  func RandomInt(min, max int) int {
    64  	mrand.Seed(time.Now().Unix())
    65  	return mrand.Intn(max-min) + min
    66  }
    67  
    68  // Elide returns the first bit of its input string with a suffix of "..." if it's longer than
    69  // a comfortable 40 characters.
    70  func Elide(value string) string {
    71  	if len(value) > 40 {
    72  		return value[0:37] + "..."
    73  	}
    74  	return value
    75  }
    76  
    77  // PrintResource returns a resource as a readable structure
    78  func PrintResource(t *testing.T, resource interface{}) {
    79  	b, _ := json.MarshalIndent(resource, "", "  ")
    80  	t.Logf(string(b))
    81  }