1package message

2

3import (

4 "strings"

5 "testing"

6)

7

8func TestMsgWriter(t *testing.T) {

9 check := func(data string, want bool) {

10 t.Helper()

11

12 b := &strings.Builder{}

13 mw := NewWriter(b)

14 if _, err := mw.Write([]byte(data)); err != nil {

15 t.Fatalf("write for message %q: %s", data, err)

16 }

17 if mw.HaveBody != want {

18 t.Fatalf("got %v, expected %v, for message %q", mw.HaveBody, want, data)

19 }

20

21 b = &strings.Builder{}

22 mw = NewWriter(b)

23 for i := range data {

24 if _, err := mw.Write([]byte(data[i : i+1])); err != nil {

25 t.Fatalf("write for message %q: %s", data, err)

26 }

27 }

28 if mw.HaveBody != want {

29 t.Fatalf("got %v, expected %v, for message %q", mw.HaveBody, want, data)

30 }

31 }

32

33 check("no header", false)

34 check("no header\r\n", false)

35 check("key: value\r\n\r\n", true)

36 check("key: value\r\n\r\nbody", true)

37 check("key: value\n\nbody", true)

38 check("key: value\n\r\nbody", true)

39 check("key: value\r\rbody", false)

40 check("\r\n\r\n", true)

41 check("\r\n\r\nbody", true)

42 check("\r\nbody", true)

43

44 // Check \n is replaced with \r\n.

45 var b strings.Builder

46 mw := NewWriter(&b)

47 msg := "key: value\n\nline1\r\nline2\nx\n.\n"

48 _, err := mw.Write([]byte(msg))

49 tcheck(t, err, "write")

50 got := b.String()

51 exp := "key: value\r\n\r\nline1\r\nline2\r\nx\r\n.\r\n"

52 if got != exp {

53 t.Fatalf("got %q, expected %q", got, exp)

54 }

55}

56

57func TestMsgWriterIssue117(t *testing.T) {

58 var b strings.Builder

59 mw := NewWriter(&b)

60

61 // Write header and header/body separator, but with CR missing.

62 _, err := mw.Write([]byte("a: b\n\n"))

63 tcheck(t, err, "write")

64

65 // Write start of a line. The newline follows in a second write. Just because of buffering.

66 _, err = mw.Write([]byte("body\r"))

67 tcheck(t, err, "write")

68

69 // Finish the line. The bug is that w.tail was only updated while writing headers,

70 // not while writing message data for the body. That makes the code think this \n

71 // wasn't preceded by a \r, causing it to add a \r. And we end up with \r\r\n in

72 // the file.

73 _, err = mw.Write([]byte("\n"))

74 tcheck(t, err, "write")

75

76 got := b.String()

77 exp := "a: b\r\n\r\nbody\r\n"

78 if got != exp {

79 t.Fatalf("got %q, expected %q", got, exp)

80 }

81}

82