go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/common/testing/httpmitm/example_httpmitm_test.go (about)

     1  // Copyright 2015 The LUCI Authors.
     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  //      http://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 httpmitm
    16  
    17  import (
    18  	"bytes"
    19  	"fmt"
    20  	"net/http"
    21  	"net/http/httptest"
    22  	"strings"
    23  )
    24  
    25  func getBody(s string) (body []string) {
    26  	pastHeaders := false
    27  	for _, part := range strings.Split(s, "\r\n") {
    28  		if pastHeaders {
    29  			body = append(body, part)
    30  		} else if part == "" {
    31  			pastHeaders = true
    32  		}
    33  	}
    34  	return
    35  }
    36  
    37  func Example() {
    38  	// Setup test server.
    39  	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    40  		w.Write([]byte("Hello, Client!"))
    41  	}))
    42  	defer ts.Close()
    43  
    44  	// Setup instrumented client.
    45  	type record struct {
    46  		o Origin
    47  		d string
    48  	}
    49  	var records []*record
    50  	client := http.Client{
    51  		Transport: &Transport{
    52  			Callback: func(o Origin, data []byte, err error) {
    53  				records = append(records, &record{o, string(data)})
    54  			},
    55  		},
    56  	}
    57  
    58  	_, err := client.Post(ts.URL, "test", bytes.NewBufferString("Hail, Server!"))
    59  	if err != nil {
    60  		return
    61  	}
    62  
    63  	// There should be two records: request and response.
    64  	for idx, r := range records {
    65  		fmt.Printf("%d) %s\n", idx, r.o)
    66  		for _, line := range getBody(r.d) {
    67  			fmt.Println(line)
    68  		}
    69  	}
    70  
    71  	// Output:
    72  	// 0) Request
    73  	// Hail, Server!
    74  	// 1) Response
    75  	// Hello, Client!
    76  }