blob: 7308d7364cfbfe346513e7249de25521fdb1390e [file] [log] [blame]
// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package testutil
import (
"bytes"
"fmt"
"path/filepath"
"runtime"
"strconv"
"testing"
"time"
)
// Retry runs function f for up to maxAttempts times until f returns successfully, and reports whether f was run successfully.
// It will sleep for the given period between invocations of f.
// Use the provided *testutil.R instead of a *testing.T from the function.
func Retry(t *testing.T, maxAttempts int, sleep time.Duration, f func(r *R)) bool {
for attempt := 1; attempt <= maxAttempts; attempt++ {
r := &R{Attempt: attempt, log: &bytes.Buffer{}}
f(r)
if !r.failed {
if r.log.Len() != 0 {
t.Logf("Success after %d attempts:%s", attempt, r.log.String())
}
return true
}
if attempt == maxAttempts {
t.Logf("FAILED after %d attempts:%s", attempt, r.log.String())
t.Fail()
}
time.Sleep(sleep)
}
return false
}
// RetryWithoutTest is a variant of Retry that does not use a testing parameter.
// It is meant for testing utilities that do not pass around the testing context, such as cloudrunci.
func RetryWithoutTest(maxAttempts int, sleep time.Duration, f func(r *R)) bool {
for attempt := 1; attempt <= maxAttempts; attempt++ {
r := &R{Attempt: attempt, log: &bytes.Buffer{}}
f(r)
if !r.failed {
if r.log.Len() != 0 {
r.Logf("Success after %d attempts:%s", attempt, r.log.String())
}
return true
}
if attempt == maxAttempts {
r.Logf("FAILED after %d attempts:%s", attempt, r.log.String())
return false
}
time.Sleep(sleep)
}
return false
}
// R is passed to each run of a flaky test run, manages state and accumulates log statements.
type R struct {
// The number of current attempt.
Attempt int
failed bool
log *bytes.Buffer
}
// Fail marks the run as failed, and will retry once the function returns.
func (r *R) Fail() {
r.failed = true
}
// Errorf is equivalent to Logf followed by Fail.
func (r *R) Errorf(s string, v ...interface{}) {
r.logf(s, v...)
r.Fail()
}
// Logf formats its arguments and records it in the error log.
// The text is only printed for the final unsuccessful run or the first successful run.
func (r *R) Logf(s string, v ...interface{}) {
r.logf(s, v...)
}
func (r *R) logf(s string, v ...interface{}) {
fmt.Fprint(r.log, "\n")
fmt.Fprint(r.log, lineNumber())
fmt.Fprintf(r.log, s, v...)
}
func lineNumber() string {
_, file, line, ok := runtime.Caller(3) // logf, public func, user function
if !ok {
return ""
}
return filepath.Base(file) + ":" + strconv.Itoa(line) + ": "
}