README
1NAME
2 "Test::HexString" - test binary strings with hex dump diagnostics
3
4SYNOPSIS
5 use Test::More tests => 1;
6 use Test::HexString;
7
8 my $data = generate_some_output;
9
10 is_hexstr( $data, "\x01\x02\x03\x04", 'Generated output' );
11
12DESCRIPTION
13 This testing module provides a single function, "is_hexstr()", which
14 asserts that the given string matches what was expected. When the
15 strings match (i.e. compare equal using the "eq" operator), the
16 behaviour is identical to the usual "is()" function provided by
17 "Test::More".
18
19 When the strings are different, a hex dump is produced as diagnostic,
20 rather than the string values being printed raw. This may be beneficial
21 if the string contains largely binary data, such as may be produced by
22 binary file or network protocol modules.
23
24 To print the hex dump when it fails, each string is broken into 16 byte
25 chunks. The first pair of chunks that fail to match are then printed, in
26 both hexadecimal and character form, in a message in the following
27 format:
28
29 # Failed test at -e line 1.
30 # at bytes 0-0xf (0-15)
31 # got: | 61 20 6c 6f 6e 67 20 73 74 72 69 6e 67 20 68 65 |a long string he|
32 # exp: | 61 20 6c 6f 6e 67 20 53 74 72 69 6e 67 20 68 65 |a long String he|
33 # Looks like you failed 1 test of 1.
34
35 Only bytes in the range "0x20-0x7e" are printed as literal characters.
36 Any other byte is rendered as ".":
37
38 # Failed test at -e line 1.
39 # at bytes 0-0xf (0-15)
40 # got: | 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f |................|
41 # exp: | 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 |................|
42 # Looks like you failed 1 test of 1.
43
44 Only the first differing line is printed; because otherwise it may
45 result in a long output because of misaligned bytes.
46
47 If STDOUT is a terminal, then different bytes are printed in bold for
48 visibility.
49
50FUNCTIONS
51 is_hexstr( $got, $expect, $name )
52 Test that the string $got is what was expected by $expect. If the
53 strings are not equal, a hex dump is printed showing the region where
54 they first start to differ.
55
56AUTHOR
57 Paul Evans <leonerd@leonerd.org.uk>
58
59