1package imapserver

2

3import (

4 "errors"

5 "fmt"

6 "testing"

7)

8

9func TestUTF7(t *testing.T) {

10 check := func(input string, output string, expErr error) {

11 t.Helper()

12

13 r, err := utf7decode(input)

14 if r != output {

15 t.Fatalf("got %q, expected %q (err %v), for input %q", r, output, err, input)

16 }

17 if (expErr == nil) != (err == nil) || err != nil && !errors.Is(err, expErr) {

18 t.Fatalf("got err %v, expected %v", err, expErr)

19 }

20 if expErr == nil {

21 expInput := utf7encode(output)

22 if expInput != input {

23 t.Fatalf("encoding, got %s, expected %s", expInput, input)

24 }

25 }

26 }

27

28 check("plain", "plain", nil)

29 check("&Jjo-", "☺", nil)

30 check("test&Jjo-", "test☺", nil)

31 check("&Jjo-test&Jjo-", "☺test☺", nil)

32 check("&Jjo-test", "☺test", nil)

33 check("&-", "&", nil)

34 check("&Jjo", "", errUTF7UnfinishedShift) // missing closing -

35 check("&Jjo-&-", "", errUTF7SuperfluousShift) // shift just after unshift not allowed, should have been a single shift.

36 check("&AGE-", "", errUTF7UnneededShift) // Just 'a', does not need utf7.

37 check("&☺-", "", errUTF7Base64)

38 check("&YQ-", "", errUTF7OddSized) // Just a single byte 'a'

39 check("&2AHcNw-", "𐐷", nil)

40 check(fmt.Sprintf("&%s-", utf7encoding.EncodeToString([]byte{0xdc, 0x00, 0xd8, 0x00})), "", errUTF7BadSurrogate) // Low & high surrogate swapped.

41 check(fmt.Sprintf("&%s-", utf7encoding.EncodeToString([]byte{0, 1, 0xdc, 0x00})), "", errUTF7BadSurrogate) // ASCII + high surrogate.

42 check(fmt.Sprintf("&%s-", utf7encoding.EncodeToString([]byte{0, 1, 0xd8, 0x00})), "", errUTF7BadSurrogate) // ASCII + low surrogate.

43 check(fmt.Sprintf("&%s-", utf7encoding.EncodeToString([]byte{0xd8, 0x00, 0, 1})), "", errUTF7BadSurrogate) // low surrogate + ASCII.

44 check(fmt.Sprintf("&%s-", utf7encoding.EncodeToString([]byte{0xdc, 0x00, 0, 1})), "", errUTF7BadSurrogate) // high surrogate + ASCII.

45

46 // ../rfc/9051:7967

47 check("~peter/mail/&U,BTFw-/&ZeVnLIqe-", "~peter/mail/台北/日本語", nil)

48 check("&U,BTFw-&ZeVnLIqe-", "", errUTF7SuperfluousShift)

49}

50