Add gotestyourself to vendor.

Signed-off-by: Daniel Nephin <dnephin@docker.com>

vendor/github.com/gotestyourself/gotestyourself/poll/poll.go

@@ -0,0 +1,133 @@
+/*Package poll provides tools for testing asynchronous code.
+ */
+package poll
+
+import (
+	"fmt"
+	"time"
+)
+
+// TestingT is the subset of testing.T used by WaitOn
+type TestingT interface {
+	LogT
+	Fatalf(format string, args ...interface{})
+}
+
+// LogT is a logging interface that is passed to the WaitOn check function
+type LogT interface {
+	Log(args ...interface{})
+	Logf(format string, args ...interface{})
+}
+
+// Settings are used to configure the behaviour of WaitOn
+type Settings struct {
+	// Timeout is the maximum time to wait for the condition. Defaults to 10s
+	Timeout time.Duration
+	// Delay is the time to sleep between checking the condition. Detaults to
+	// 1ms
+	Delay time.Duration
+}
+
+func defaultConfig() *Settings {
+	return &Settings{Timeout: 10 * time.Second, Delay: time.Millisecond}
+}
+
+// SettingOp is a function which accepts and modifies Settings
+type SettingOp func(config *Settings)
+
+// WithDelay sets the delay to wait between polls
+func WithDelay(delay time.Duration) SettingOp {
+	return func(config *Settings) {
+		config.Delay = delay
+	}
+}
+
+// WithTimeout sets the timeout
+func WithTimeout(timeout time.Duration) SettingOp {
+	return func(config *Settings) {
+		config.Timeout = timeout
+	}
+}
+
+// Result of a check performed by WaitOn
+type Result interface {
+	// Error indicates that the check failed and polling should stop, and the
+	// the has failed
+	Error() error
+	// Done indicates that polling should stop, and the test should proceed
+	Done() bool
+	// Message provides the most recent state when polling has not completed
+	Message() string
+}
+
+type result struct {
+	done    bool
+	message string
+	err     error
+}
+
+func (r result) Done() bool {
+	return r.done
+}
+
+func (r result) Message() string {
+	return r.message
+}
+
+func (r result) Error() error {
+	return r.err
+}
+
+// Continue returns a Result that indicates to WaitOn that it should continue
+// polling. The message text will be used as the failure message if the timeout
+// is reached.
+func Continue(message string, args ...interface{}) Result {
+	return result{message: fmt.Sprintf(message, args...)}
+}
+
+// Success returns a Result where Done() returns true, which indicates to WaitOn
+// that it should stop polling and exit without an error.
+func Success() Result {
+	return result{done: true}
+}
+
+// Error returns a Result that indicates to WaitOn that it should fail the test
+// and stop polling.
+func Error(err error) Result {
+	return result{err: err}
+}
+
+// WaitOn a condition or until a timeout. Poll by calling check and exit when
+// check returns a done Result. To fail a test and exit polling with an error
+// return a error result.
+func WaitOn(t TestingT, check func(t LogT) Result, pollOps ...SettingOp) {
+	config := defaultConfig()
+	for _, pollOp := range pollOps {
+		pollOp(config)
+	}
+
+	var lastMessage string
+	after := time.After(config.Timeout)
+	chResult := make(chan Result)
+	for {
+		go func() {
+			chResult <- check(t)
+		}()
+		select {
+		case <-after:
+			if lastMessage == "" {
+				lastMessage = "first check never completed"
+			}
+			t.Fatalf("timeout hit after %s: %s", config.Timeout, lastMessage)
+		case result := <-chResult:
+			switch {
+			case result.Error() != nil:
+				t.Fatalf("polling check failed: %s", result.Error())
+			case result.Done():
+				return
+			}
+			time.Sleep(config.Delay)
+			lastMessage = result.Message()
+		}
+	}
+}