.\" Automatically generated by Pod::Man 4.10 (Pod::Simple 3.35) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Test::Differences 3pm" .TH Test::Differences 3pm "2019-02-21" "perl v5.28.1" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Test::Differences \- Test strings and data structures and show differences if not ok .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 2 \& use Test; ## Or use Test::More \& use Test::Differences; \& \& eq_or_diff $got, "a\enb\enc\en", "testing strings"; \& eq_or_diff \e@got, [qw( a b c )], "testing arrays"; \& \& ## Passing options: \& eq_or_diff $got, $expected, $name, { context => 300 }; ## options \& \& ## Using with DBI\-like data structures \& \& use DBI; \& \& ... open connection & prepare statement and @expected_... here... \& \& eq_or_diff $sth\->fetchall_arrayref, \e@expected_arrays "testing DBI arrays"; \& eq_or_diff $sth\->fetchall_hashref, \e@expected_hashes, "testing DBI hashes"; \& \& ## To force textual or data line numbering (text lines are numbered 1..): \& eq_or_diff_text ...; \& eq_or_diff_data ...; .Ve .SH "EXPORT" .IX Header "EXPORT" This module exports three test functions and four diff-style functions: .IP "\(bu" 4 Test functions .RS 4 .IP "\(bu" 4 \&\f(CW\*(C`eq_or_diff\*(C'\fR .IP "\(bu" 4 \&\f(CW\*(C`eq_or_diff_data\*(C'\fR .IP "\(bu" 4 \&\f(CW\*(C`eq_or_diff_text\*(C'\fR .RE .RS 4 .RE .IP "\(bu" 4 Diff style functions .RS 4 .IP "\(bu" 4 \&\f(CW\*(C`table_diff\*(C'\fR (the default) .IP "\(bu" 4 \&\f(CW\*(C`unified_diff\*(C'\fR .IP "\(bu" 4 \&\f(CW\*(C`oldstyle_diff\*(C'\fR .IP "\(bu" 4 \&\f(CW\*(C`context_diff\*(C'\fR .RE .RS 4 .RE .SH "DESCRIPTION" .IX Header "DESCRIPTION" When the code you're testing returns multiple lines, records or data structures and they're just plain wrong, an equivalent to the Unix \&\f(CW\*(C`diff\*(C'\fR utility may be just what's needed. Here's output from an example test script that checks two text documents and then two (trivial) data structures: .PP .Vb 10 \& t/99example....1..3 \& not ok 1 \- differences in text \& # Failed test ((eval 2) at line 14) \& # +\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | Ln|Got |Expected | \& # +\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | 1|this is line 1 |this is line 1 | \& # * 2|this is line 2 |this is line b * \& # | 3|this is line 3 |this is line 3 | \& # +\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& not ok 2 \- differences in whitespace \& # Failed test ((eval 2) at line 20) \& # +\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | Ln|Got |Expected | \& # +\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | 1| indented | indented | \& # * 2| indented |\etindented * \& # | 3| indented | indented | \& # +\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& not ok 3 \& # Failed test ((eval 2) at line 22) \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | Elt|Got |Expected | \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # * 0|bless( [ |[ * \& # * 1| \*(AqMove along, nothing to see here\*(Aq | \*(AqDry, humorless message\*(Aq * \& # * 2|], \*(AqTest::Builder\*(Aq ) |] * \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # Looks like you failed 3 tests of 3. .Ve .PP eq_or_diff_...() compares two strings or (limited) data structures and either emits an ok indication or a side-by-side diff. Test::Differences is designed to be used with Test.pm and with Test::Simple, Test::More, and other Test::Builder based testing modules. As the \s-1SYNOPSIS\s0 shows, another testing module must be used as the basis for your test suite. .SH "OPTIONS" .IX Header "OPTIONS" The options to \f(CW\*(C`eq_or_diff\*(C'\fR give some fine-grained control over the output. .IP "\(bu" 4 \&\f(CW\*(C`context\*(C'\fR .Sp This allows you to control the amount of context shown: .Sp .Vb 1 \& eq_or_diff $got, $expected, $name, { context => 50000 }; .Ve .Sp will show you lots and lots of context. Normally, \fBeq_or_diff()\fR uses some heuristics to determine whether to show 3 lines of context (like a normal unified diff) or 25 lines. .IP "\(bu" 4 \&\f(CW\*(C`data_type\*(C'\fR .Sp \&\f(CW\*(C`text\*(C'\fR or \f(CW\*(C`data\*(C'\fR. See \f(CW\*(C`eq_or_diff_text\*(C'\fR and \f(CW\*(C`eq_or_diff_data\*(C'\fR to understand this. You can usually ignore this. .IP "\(bu" 4 \&\f(CW\*(C`Sortkeys\*(C'\fR .Sp If passed, whatever value is added is used as the argument for Data::Dumper Sortkeys option. See the Data::Dumper docs to understand how you can control the Sortkeys behavior. .IP "\(bu" 4 \&\f(CW\*(C`filename_a\*(C'\fR and \f(CW\*(C`filename_b\*(C'\fR .Sp The column headers to use in the output. They default to 'Got' and 'Expected'. .SH "DIFF STYLES" .IX Header "DIFF STYLES" For extremely long strings, a table diff can wrap on your screen and be hard to read. If you are comfortable with different diff formats, you can switch to a format more suitable for your data. These are the four formats supported by the Text::Diff module and are set with the following functions: .IP "\(bu" 4 \&\f(CW\*(C`table_diff\*(C'\fR (the default) .IP "\(bu" 4 \&\f(CW\*(C`unified_diff\*(C'\fR .IP "\(bu" 4 \&\f(CW\*(C`oldstyle_diff\*(C'\fR .IP "\(bu" 4 \&\f(CW\*(C`context_diff\*(C'\fR .PP You can run the following to understand the different diff output styles: .PP .Vb 2 \& use Test::More \*(Aqno_plan\*(Aq; \& use Test::Differences; \& \& my $long_string = join \*(Aq\*(Aq => 1..40; \& \& TODO: { \& local $TODO = \*(AqTesting diff styles\*(Aq; \& \& # this is the default and does not need to explicitly set unless you need \& # to reset it back from another diff type \& table_diff; \& eq_or_diff $long_string, "\-$long_string", \*(Aqtable diff\*(Aq; \& \& unified_diff; \& eq_or_diff $long_string, "\-$long_string", \*(Aqunified diff\*(Aq; \& \& context_diff; \& eq_or_diff $long_string, "\-$long_string", \*(Aqcontext diff\*(Aq; \& \& oldstyle_diff; \& eq_or_diff $long_string, "\-$long_string", \*(Aqoldstyle diff\*(Aq; \& } .Ve .SH "UNICODE" .IX Header "UNICODE" Generally you'll find that the following test output is disappointing. .PP .Vb 1 \& use Test::Differences; \& \& my $want = { \*(AqTraditional Chinese\*(Aq => \*(Aq中國\*(Aq }; \& my $have = { \*(AqTraditional Chinese\*(Aq => \*(Aq中国\*(Aq }; \& \& eq_or_diff $have, $want, \*(AqUnicode, baby\*(Aq; .Ve .PP The output looks like this: .PP .Vb 10 \& # Failed test \*(AqUnicode, baby\*(Aq \& # at t/unicode.t line 12. \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | Elt|Got |Expected | \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | 0|\*(AqTraditional Chinese\*(Aq |\*(AqTraditional Chinese\*(Aq | \& # * 1|\*(Aq\exe4\exb8\exad\exe5\ex9b\exbd\*(Aq |\*(Aq\exe4\exb8\exad\exe5\ex9c\ex8b\*(Aq * \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # Looks like you failed 1 test of 1. \& Dubious, test returned 1 (wstat 256, 0x100) .Ve .PP This is generally not helpful and someone points out that you didn't declare your test program as being utf8, so you do that: .PP .Vb 2 \& use Test::Differences; \& use utf8; \& \& my $want = { \*(AqTraditional Chinese\*(Aq => \*(Aq中國\*(Aq }; \& my $have = { \*(AqTraditional Chinese\*(Aq => \*(Aq中国\*(Aq }; \& \& eq_or_diff $have, $want, \*(AqUnicode, baby\*(Aq; .Ve .PP Here's what you get: .PP .Vb 11 \& # Failed test \*(AqUnicode, baby\*(Aq \& # at t/unicode.t line 12. \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | Elt|Got |Expected | \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | 0|\*(AqTraditional Chinese\*(Aq |\*(AqTraditional Chinese\*(Aq | \& # * 1|\*(Aq\ex{4e2d}\ex{56fd}\*(Aq |\*(Aq\ex{4e2d}\ex{570b}\*(Aq * \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # Looks like you failed 1 test of 1. \& Dubious, test returned 1 (wstat 256, 0x100) \& Failed 1/1 subtests .Ve .PP That's better, but still awful. However, if you have \f(CW\*(C`Text::Diff\*(C'\fR 0.40 or higher installed, you can add this to your code: .PP .Vb 1 \& BEGIN { $ENV{DIFF_OUTPUT_UNICODE} = 1 } .Ve .PP Make sure you do this \fIbefore\fR you load Text::Diff. Then this is the output: .PP .Vb 6 \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | Elt|Got |Expected | \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | 0|\*(AqTraditional Chinese\*(Aq |\*(AqTraditional Chinese\*(Aq | \& # * 1|\*(Aq中国\*(Aq |\*(Aq中國\*(Aq * \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ .Ve .SH "DEPLOYING" .IX Header "DEPLOYING" There are several basic ways of deploying Test::Differences requiring more or less labor by you or your users. .IP "\(bu" 4 Fallback to \f(CW\*(C`is_deeply\*(C'\fR. .Sp This is your best option if you want this module to be optional. .Sp .Vb 6 \& use Test::More; \& BEGIN { \& if (!eval q{ use Test::Differences; 1 }) { \& *eq_or_diff = \e&is_deeply; \& } \& } .Ve .IP "\(bu" 4 .Sp .Vb 1 \& eval "use Test::Differences"; .Ve .Sp If you want to detect the presence of Test::Differences on the fly, something like the following code might do the trick for you: .Sp .Vb 1 \& use Test qw( !ok ); ## get all syms *except* ok \& \& eval "use Test::Differences"; \& use Data::Dumper; \& \& sub ok { \& goto &eq_or_diff if defined &eq_or_diff && @_ > 1; \& @_ = map ref $_ ? Dumper( @_ ) : $_, @_; \& goto Test::&ok; \& } \& \& plan tests => 1; \& \& ok "a", "b"; .Ve .IP "\(bu" 4 \&\s-1PREREQ_PM\s0 => { .... \*(L"Test::Differences\*(R" => 0, ... } .Sp This method will let \s-1CPAN\s0 and \s-1CPANPLUS\s0 users download it automatically. It will discomfit those users who choose/have to download all packages manually. .IP "\(bu" 4 t/lib/Test/Differences.pm, t/lib/Text/Diff.pm, ... .Sp By placing Test::Differences and its prerequisites in the t/lib directory, you avoid forcing your users to download the Test::Differences manually if they aren't using \s-1CPAN\s0 or \s-1CPANPLUS.\s0 .Sp If you put a \f(CW\*(C`use lib "t/lib";\*(C'\fR in the top of each test suite before the \&\f(CW\*(C`use Test::Differences;\*(C'\fR, \f(CW\*(C`make test\*(C'\fR should work well. .Sp You might want to check once in a while for new Test::Differences releases if you do this. .SH "LIMITATIONS" .IX Header "LIMITATIONS" .ie n .SS """Test"" or ""Test::More""" .el .SS "\f(CWTest\fP or \f(CWTest::More\fP" .IX Subsection "Test or Test::More" This module \*(L"mixes in\*(R" with Test.pm or any of the test libraries based on Test::Builder (Test::Simple, Test::More, etc). It does this by peeking to see whether Test.pm or Test/Builder.pm is in \f(CW%INC\fR, so if you are not using one of those, it will print a warning and play dumb by not emitting test numbers (or incrementing them). If you are using one of these, it should interoperate nicely. .SS "Exporting" .IX Subsection "Exporting" Exports all 3 functions by default (and by design). Use .PP .Vb 1 \& use Test::Differences (); .Ve .PP to suppress this behavior if you don't like the namespace pollution. .PP This module will not override functions like \fBok()\fR, \fBis()\fR, \fBis_deeply()\fR, etc. If it did, then you could \f(CW\*(C`eval "use Test::Differences qw( is_deeply );"\*(C'\fR to get automatic upgrading to diffing behaviors without the \f(CW\*(C`sub my_ok\*(C'\fR shown above. Test::Differences intentionally does not provide this behavior because this would mean that Test::Differences would need to emulate every popular test module out there, which would require far more coding and maintenance that I'm willing to do. Use the eval and my_ok deployment shown above if you want some level of automation. .SS "Unicode" .IX Subsection "Unicode" Perls before 5.6.0 don't support characters > 255 at all, and 5.6.0 seems broken. This means that you might get odd results using perl5.6.0 with unicode strings. .ie n .SS """Data::Dumper"" and older Perls." .el .SS "\f(CWData::Dumper\fP and older Perls." .IX Subsection "Data::Dumper and older Perls." Relies on Data::Dumper (for now), which, prior to perl5.8, will not always report hashes in the same order. \f(CW $Data::Dumper::Sortkeys \fR \fIis\fR set to 1, so on more recent versions of Data::Dumper, this should not occur. Check \s-1CPAN\s0 to see if it's been peeled out of the main perl distribution and backported. Reported by Ilya Martynov , although the Sortkeys \*(L"future perfect\*(R" workaround has been set in anticipation of a new Data::Dumper for a while. Note that the two hashes should report the same here: .PP .Vb 10 \& not ok 5 \& # Failed test (t/ctrl/05\-home.t at line 51) \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | Elt|Got | Elt|Expected | \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ \& # | 0|{ | 0|{ | \& # | 1| \*(Aqpassword\*(Aq => \*(Aq\*(Aq, | 1| \*(Aqpassword\*(Aq => \*(Aq\*(Aq, | \& # * 2| \*(Aqmethod\*(Aq => \*(Aqlogin\*(Aq, * | | \& # | 3| \*(Aqctrl\*(Aq => \*(Aqhome\*(Aq, | 2| \*(Aqctrl\*(Aq => \*(Aqhome\*(Aq, | \& # | | * 3| \*(Aqmethod\*(Aq => \*(Aqlogin\*(Aq, * \& # | 4| \*(Aqemail\*(Aq => \*(Aqtest\*(Aq | 4| \*(Aqemail\*(Aq => \*(Aqtest\*(Aq | \& # | 5|} | 5|} | \& # +\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+ .Ve .PP Data::Dumper also overlooks the difference between .PP .Vb 2 \& $a[0] = \e$a[1]; \& $a[1] = \e$a[0]; # $a[0] = \e$a[1] .Ve .PP and .PP .Vb 3 \& $x = \e$y; \& $y = \e$x; \& @a = ( $x, $y ); # $a[0] = \e$y, not \e$a[1] .Ve .PP The former involves two scalars, the latter 4: \f(CW$x\fR, \f(CW$y\fR, and \f(CW@a\fR[0,1]. This was carefully explained to me in words of two syllables or less by Yves Orton . The plan to address this is to allow you to select Data::Denter or some other module of your choice as an option. .SH "AUTHORS" .IX Header "AUTHORS" .Vb 1 \& Barrie Slaymaker \- original author \& \& Curtis "Ovid" Poe \& \& David Cantrell .Ve .SH "LICENSE" .IX Header "LICENSE" Copyright Barrie Slaymaker, Curtis \*(L"Ovid\*(R" Poe, and David Cantrell. .PP All Rights Reserved. .PP You may use, distribute and modify this software under the terms of the \s-1GNU\s0 public license, any version, or the Artistic license.