tailscale/tstest/tstest.go
Brad Fitzpatrick 08782b92f7 tstest: add WaitFor helper
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-04-29 14:43:46 -07:00

32 lines
823 B
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package tstest provides utilities for use in unit tests.
package tstest
import (
"context"
"time"
"tailscale.com/logtail/backoff"
"tailscale.com/types/logger"
)
// WaitFor retries try for up to maxWait.
// It returns nil once try returns nil the first time.
// If maxWait passes without success, it returns try's last error.
func WaitFor(maxWait time.Duration, try func() error) error {
bo := backoff.NewBackoff("wait-for", logger.Discard, maxWait/4)
deadline := time.Now().Add(maxWait)
var err error
for time.Now().Before(deadline) {
err = try()
if err == nil {
break
}
bo.BackOff(context.Background(), err)
}
return err
}