github.com/jenkins-x/jx/v2@v2.1.155/pkg/tests/retry.go (about) 1 // Copyright 2019 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package tests 16 17 import ( 18 "bytes" 19 "fmt" 20 "path/filepath" 21 "runtime" 22 "strconv" 23 "testing" 24 "time" 25 ) 26 27 // Retry runs function f for up to maxAttempts times until f returns successfully, and reports whether f was run successfully. 28 // It will sleep for the given period between invocations of f. 29 // Use the provided *tests.R instead of a *testing.T from the function. 30 func Retry(t *testing.T, maxAttempts int, sleep time.Duration, f func(r *R)) bool { 31 for attempt := 1; attempt <= maxAttempts; attempt++ { 32 r := &R{Attempt: attempt, log: &bytes.Buffer{}} 33 34 f(r) 35 36 if !r.failed { 37 if r.log.Len() != 0 { 38 t.Logf("Success after %d attempts:%s", attempt, r.log.String()) 39 } 40 return true 41 } 42 43 if attempt == maxAttempts { 44 t.Logf("FAILED after %d attempts:%s", attempt, r.log.String()) 45 t.Fail() 46 } 47 48 time.Sleep(sleep) 49 } 50 return false 51 } 52 53 // R is passed to each run of a flaky test run, manages state and accumulates log statements. 54 type R struct { 55 // The number of current attempt. 56 Attempt int 57 58 failed bool 59 log *bytes.Buffer 60 } 61 62 // Fail marks the run as failed, and will retry once the function returns. 63 func (r *R) Fail() { 64 r.failed = true 65 } 66 67 // Errorf is equivalent to Logf followed by Fail. 68 func (r *R) Errorf(s string, v ...interface{}) { 69 r.logf(s, v...) 70 r.Fail() 71 } 72 73 // Logf formats its arguments and records it in the error log. 74 // The text is only printed for the final unsuccessful run or the first successful run. 75 func (r *R) Logf(s string, v ...interface{}) { 76 r.logf(s, v...) 77 } 78 79 func (r *R) logf(s string, v ...interface{}) { 80 fmt.Fprint(r.log, "\n") 81 fmt.Fprint(r.log, lineNumber()) 82 fmt.Fprintf(r.log, s, v...) 83 } 84 85 func lineNumber() string { 86 _, file, line, ok := runtime.Caller(3) // logf, public func, user function 87 if !ok { 88 return "" 89 } 90 return filepath.Base(file) + ":" + strconv.Itoa(line) + ": " 91 }