1package gock 2 3import ( 4 "bytes" 5 "io" 6 "io/ioutil" 7 "net/http" 8 "strconv" 9 "time" 10) 11 12// Responder builds a mock http.Response based on the given Response mock. 13func Responder(req *http.Request, mock *Response, res *http.Response) (*http.Response, error) { 14 // If error present, reply it 15 err := mock.Error 16 if err != nil { 17 return nil, err 18 } 19 20 if res == nil { 21 res = createResponse(req) 22 } 23 24 // Apply response filter 25 for _, filter := range mock.Filters { 26 if !filter(res) { 27 return res, nil 28 } 29 } 30 31 // Define mock status code 32 if mock.StatusCode != 0 { 33 res.Status = strconv.Itoa(mock.StatusCode) + " " + http.StatusText(mock.StatusCode) 34 res.StatusCode = mock.StatusCode 35 } 36 37 // Define headers by merging fields 38 res.Header = mergeHeaders(res, mock) 39 40 // Define mock body, if present 41 if len(mock.BodyBuffer) > 0 { 42 res.ContentLength = int64(len(mock.BodyBuffer)) 43 res.Body = createReadCloser(mock.BodyBuffer) 44 } 45 46 // Apply response mappers 47 for _, mapper := range mock.Mappers { 48 if tres := mapper(res); tres != nil { 49 res = tres 50 } 51 } 52 53 // Sleep to simulate delay, if necessary 54 if mock.ResponseDelay > 0 { 55 // allow escaping from sleep due to request context expiration or cancellation 56 t := time.NewTimer(mock.ResponseDelay) 57 select { 58 case <-t.C: 59 case <-req.Context().Done(): 60 // cleanly stop the timer 61 if !t.Stop() { 62 <-t.C 63 } 64 } 65 } 66 67 // check if the request context has ended. we could put this up in the delay code above, but putting it here 68 // has the added benefit of working even when there is no delay (very small timeouts, already-done contexts, etc.) 69 if err = req.Context().Err(); err != nil { 70 // cleanly close the response and return the context error 71 io.Copy(ioutil.Discard, res.Body) 72 res.Body.Close() 73 return nil, err 74 } 75 76 return res, err 77} 78 79// createResponse creates a new http.Response with default fields. 80func createResponse(req *http.Request) *http.Response { 81 return &http.Response{ 82 ProtoMajor: 1, 83 ProtoMinor: 1, 84 Proto: "HTTP/1.1", 85 Request: req, 86 Header: make(http.Header), 87 Body: createReadCloser([]byte{}), 88 } 89} 90 91// mergeHeaders copies the mock headers. 92func mergeHeaders(res *http.Response, mres *Response) http.Header { 93 for key, values := range mres.Header { 94 for _, value := range values { 95 res.Header.Add(key, value) 96 } 97 } 98 return res.Header 99} 100 101// createReadCloser creates an io.ReadCloser from a byte slice that is suitable for use as an 102// http response body. 103func createReadCloser(body []byte) io.ReadCloser { 104 return ioutil.NopCloser(bytes.NewReader(body)) 105} 106