github.com/nycdavid/zeus@v0.0.0-20201208104106-9ba439429e03/go/filemonitor/filelistener_test.go (about)

     1  package filemonitor_test
     2  
     3  import (
     4  	"bufio"
     5  	"errors"
     6  	"fmt"
     7  	"io"
     8  	"math/rand"
     9  	"net"
    10  	"os"
    11  	"testing"
    12  	"time"
    13  
    14  	"github.com/burke/zeus/go/filemonitor"
    15  	slog "github.com/burke/zeus/go/shinylog"
    16  )
    17  
    18  func TestFileListener(t *testing.T) {
    19  	ln, err := net.ListenTCP("tcp", &net.TCPAddr{
    20  		IP:   net.ParseIP("127.0.0.1"),
    21  		Port: 0,
    22  	})
    23  	if err != nil {
    24  		t.Fatal(err)
    25  	}
    26  
    27  	slog.SetTraceLogger(slog.NewTraceLogger(os.Stderr))
    28  	fl := filemonitor.NewFileListener(filemonitor.DefaultFileChangeDelay, ln)
    29  	defer fl.Close()
    30  
    31  	// We should be able to add a file without connecting anything
    32  	if err := fl.Add("foo"); err != nil {
    33  		t.Fatal(err)
    34  	}
    35  
    36  	conn, err := net.DialTCP("tcp", nil, ln.Addr().(*net.TCPAddr))
    37  	if err != nil {
    38  		t.Fatal(err)
    39  	}
    40  	defer conn.Close()
    41  	scanner := bufio.NewScanner(conn)
    42  
    43  	// Can write files
    44  	files := fl.Listen()
    45  	if err := checkWrite(files, conn); err != nil {
    46  		t.Fatal(err)
    47  	}
    48  
    49  	// Can read a file add operation
    50  	want := "bar"
    51  	if err := fl.Add(want); err != nil {
    52  		t.Fatal(err)
    53  	}
    54  	conn.SetReadDeadline(time.Now().Add(time.Second))
    55  	if err := checkScan(scanner, want); err != nil {
    56  		t.Fatal(err)
    57  	}
    58  
    59  	// Can create a second connection
    60  	conn2, err := net.DialTCP("tcp", nil, ln.Addr().(*net.TCPAddr))
    61  	if err != nil {
    62  		t.Fatal(err)
    63  	}
    64  	defer conn2.Close()
    65  	scanner2 := bufio.NewScanner(conn2)
    66  
    67  	// Can write a file to the second connection
    68  	if err := checkWrite(files, conn2); err != nil {
    69  		t.Fatal(err)
    70  	}
    71  
    72  	// Can read the same file Add from two connections
    73  	want = "baz"
    74  	if err := fl.Add(want); err != nil {
    75  		t.Fatal(err)
    76  	}
    77  
    78  	conn.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
    79  	conn2.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
    80  
    81  	for i, s := range []*bufio.Scanner{scanner, scanner2} {
    82  		if err := checkScan(s, want); err != nil {
    83  			t.Errorf("%d: %v", i, err)
    84  		}
    85  	}
    86  
    87  	// Can shutdown properly
    88  	if err := fl.Close(); err != nil {
    89  		t.Fatal(err)
    90  	}
    91  
    92  	for i, c := range []net.Conn{conn, conn2} {
    93  		buf := make([]byte, 10)
    94  		c.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
    95  		if b, err := c.Read(buf); err == nil {
    96  			t.Fatalf("%d: expected EOF reading closed connection but read %d bytes: %s", i, b, buf)
    97  		} else if err != io.EOF {
    98  			t.Fatalf("%d: expected EOF but got %v", i, err)
    99  		}
   100  	}
   101  }
   102  
   103  func checkScan(scanner *bufio.Scanner, want string) error {
   104  	if scanner.Scan() {
   105  		if have := scanner.Text(); have != want {
   106  			return fmt.Errorf("expected %q, got %q", want, have)
   107  		}
   108  	} else {
   109  		if err := scanner.Err(); err != nil {
   110  			return err
   111  		}
   112  		return errors.New("Unexpected EOF")
   113  	}
   114  
   115  	return nil
   116  }
   117  
   118  func checkWrite(files <-chan []string, conn net.Conn) error {
   119  	cases := make([]string, 2)
   120  	for i := range cases {
   121  		cases[i] = fmt.Sprintf("file%d", rand.Int())
   122  	}
   123  
   124  	for i, want := range cases {
   125  		conn.SetWriteDeadline(time.Now().Add(100 * time.Millisecond))
   126  		if _, err := conn.Write([]byte(want + "\n")); err != nil {
   127  			return fmt.Errorf("Error writing %d: %v", i, err)
   128  		}
   129  	}
   130  
   131  	if err := expectChanges(files, cases[:]); err != nil {
   132  		return err
   133  	}
   134  
   135  	return nil
   136  }