istio.io/istio@v0.0.0-20240520182934-d79c90f27776/samples/tcp-echo/src/main_test.go (about)

     1  // Copyright Istio 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 main
    16  
    17  import (
    18  	"bufio"
    19  	"net"
    20  	"os"
    21  	"strings"
    22  	"testing"
    23  	"time"
    24  )
    25  
    26  // TestTcpEchoServer tests the behavior of the TCP Echo Server.
    27  func TestTcpEchoServer(t *testing.T) {
    28  	// set up test parameters
    29  	prefix := "hello"
    30  	request := "world"
    31  	want := prefix + " " + request
    32  
    33  	// start the TCP Echo Server
    34  	os.Args = []string{"main", "9000,9001", prefix}
    35  	go main()
    36  
    37  	// wait for the TCP Echo Server to start
    38  	time.Sleep(500 * time.Millisecond)
    39  
    40  	for _, addr := range []string{":9000", ":9001"} {
    41  		// connect to the TCP Echo Server
    42  		conn, err := net.Dial("tcp", addr)
    43  		if err != nil {
    44  			t.Fatalf("couldn't connect to the server: %v", err)
    45  		}
    46  		defer conn.Close()
    47  
    48  		// test the TCP Echo Server output
    49  		if _, err := conn.Write([]byte(request + "\n")); err != nil {
    50  			t.Fatalf("couldn't send request: %v", err)
    51  		} else {
    52  			reader := bufio.NewReader(conn)
    53  			if response, err := reader.ReadBytes(byte('\n')); err != nil {
    54  				t.Fatalf("couldn't read server response: %v", err)
    55  			} else if !strings.HasPrefix(string(response), want) {
    56  				t.Errorf("output doesn't match, wanted: %s, got: %s", want, response)
    57  			}
    58  		}
    59  	}
    60  }