| // 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) + ": " |
| } |