path: root/upstream/debian-bookworm/man3/Test2::Transition.3perl

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.\" ========================================================================
.\"
.IX Title "Test2::Transition 3perl"
.TH Test2::Transition 3perl "2023-11-25" "perl v5.36.0" "Perl Programmers Reference Guide"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
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.if n .ad l
.nh
.SH "NAME"
Test2::Transition \- Transition notes when upgrading to Test2
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This is where gotchas and breakages related to the Test2 upgrade are
documented. The upgrade causes Test::Builder to defer to Test2 under the hood.
This transition is mostly transparent, but there are a few cases that can trip
you up.
.SH "THINGS THAT BREAK"
.IX Header "THINGS THAT BREAK"
This is the list of scenarios that break with the new internals.
.SS "Test::Builder1.5/2 conditionals"
.IX Subsection "Test::Builder1.5/2 conditionals"
\fIThe Problem\fR
.IX Subsection "The Problem"
.PP
a few years back there were two attempts to upgrade/replace Test::Builder.
Confusingly these were called Test::Builder2 and Test::Builder1.5, in that
order. Many people put conditionals in their code to check the Test::Builder
version number and adapt their code accordingly.
.PP
The Test::Builder2/1.5 projects both died out. Now the conditional code people
added has become a mine field. A vast majority of modules broken by Test2 fall
into this category.
.PP
\fIThe Fix\fR
.IX Subsection "The Fix"
.PP
The fix is to remove all Test::Builder1.5/2 related code. Either use the
legacy Test::Builder \s-1API,\s0 or use Test2 directly.
.SS "Replacing the Test::Builder singleton"
.IX Subsection "Replacing the Test::Builder singleton"
\fIThe Problem\fR
.IX Subsection "The Problem"
.PP
Some test modules would replace the Test::Builder singleton instance with their
own instance or subclass. This was usually done to intercept or modify results
as they happened.
.PP
The Test::Builder singleton is now a simple compatibility wrapper around
Test2. The Test::Builder singleton is no longer the central place for
results. Many results bypass the Test::Builder singleton completely, which
breaks and behavior intended when replacing the singleton.
.PP
\fIThe Fix\fR
.IX Subsection "The Fix"
.PP
If you simply want to intercept all results instead of letting them go to \s-1TAP,\s0
you should look at the Test2::API docs and read about pushing a new hub onto
the hub stack. Replacing the hub temporarily is now the correct way to
intercept results.
.PP
If your goal is purely monitoring of events use the \f(CW\*(C`Test2::Hub\->listen()\*(C'\fR
method exported by Test::More to watch events as they are fired. If you wish to
modify results before they go to \s-1TAP\s0 look at the \f(CW\*(C`Test2::Hub\->filter()\*(C'\fR
method.
.SS "Directly Accessing Hash Elements"
.IX Subsection "Directly Accessing Hash Elements"
\fIThe Problem\fR
.IX Subsection "The Problem"
.PP
Some modules look directly at hash keys on the Test::Builder singleton. The
problem here is that the Test::Builder singleton no longer holds anything
important.
.PP
\fIThe Fix\fR
.IX Subsection "The Fix"
.PP
The fix is to use the \s-1API\s0 specified in Test2::API to look at or modify state
as needed.
.SS "Subtest indentation"
.IX Subsection "Subtest indentation"
\fIThe Problem\fR
.IX Subsection "The Problem"
.PP
An early change, in fact the change that made Test2 an idea, was a change to
the indentation of the subtest note. It was decided it would be more readable
to outdent the subtest note instead of having it inline with the subtest:
.PP
.Vb 4
\&    # subtest foo
\&        ok 1 \- blah
\&        1..1
\&    ok 1 \- subtest foo
.Ve
.PP
The old style indented the note:
.PP
.Vb 4
\&        # subtest foo
\&        ok 1 \- blah
\&        1..1
\&    ok 1 \- subtest foo
.Ve
.PP
This breaks tests that do string comparison of \s-1TAP\s0 output.
.PP
\fIThe Fix\fR
.IX Subsection "The Fix"
.PP
.Vb 1
\&    my $indent = $INC{\*(AqTest2/API.pm\*(Aq} ? \*(Aq\*(Aq : \*(Aq    \*(Aq;
\&
\&    is(
\&        $subtest_output,
\&        "${indent}# subtest foo",
\&        "Got subtest note"
\&    );
.Ve
.PP
Check if \f(CW$INC{\*(AqTest2/API.pm\*(Aq}\fR is set, if it is then no indentation should be
expected. If it is not set, then the old Test::Builder is in use, indentation
should be expected.
.SH "DISTRIBUTIONS THAT BREAK OR NEED TO BE UPGRADED"
.IX Header "DISTRIBUTIONS THAT BREAK OR NEED TO BE UPGRADED"
This is a list of cpan modules that have been known to have been broken by the
upgrade at one point.
.SS "\s-1WORKS BUT TESTS WILL FAIL\s0"
.IX Subsection "WORKS BUT TESTS WILL FAIL"
These modules still function correctly, but their test suites will not pass. If
you already have these modules installed then you can continue to use them. If
you are trying to install them after upgrading Test::Builder you will need to
force installation, or bypass the broken tests.
.IP "Test::DBIx::Class::Schema" 4
.IX Item "Test::DBIx::Class::Schema"
This module has a test that appears to work around a Test::Builder bug. The bug
appears to have been fixed by Test2, which means the workaround causes a
failure. This can be easily updated, but nobody has done so yet.
.Sp
Known broken in versions: 1.0.9 and older
.IP "Device::Chip" 4
.IX Item "Device::Chip"
Tests break due to subtest indentation.
.Sp
Known broken in version 0.07. Apparently works fine in 0.06 though. Patch has
been submitted to fix the issue.
.SS "\s-1UPGRADE SUGGESTED\s0"
.IX Subsection "UPGRADE SUGGESTED"
These are modules that did not break, but had broken test suites that have
since been fixed.
.IP "Test::Exception" 4
.IX Item "Test::Exception"
Old versions work fine, but have a minor test name behavior that breaks with
Test2. Old versions will no longer install because of this. The latest version
on \s-1CPAN\s0 will install just fine. Upgrading is not required, but is recommended.
.Sp
Fixed in version: 0.43
.IP "Data::Peek" 4
.IX Item "Data::Peek"
Some tests depended on \f(CW$!\fR and \f(CW$?\fR being modified in subtle ways. A patch
was applied to correct things that changed.
.Sp
The module itself works fine, there is no need to upgrade.
.Sp
Fixed in version: 0.45
.IP "circular::require" 4
.IX Item "circular::require"
Some tests were fragile and required base.pm to be loaded at a late stage.
Test2 was loading base.pm too early. The tests were updated to fix this.
.Sp
The module itself never broke, you do not need to upgrade.
.Sp
Fixed in version: 0.12
.IP "Test::Module::Used" 4
.IX Item "Test::Module::Used"
A test worked around a now-fixed planning bug. There is no need to upgrade if
you have an old version installed. New versions install fine if you want them.
.Sp
Fixed in version: 0.2.5
.IP "Test::Moose::More" 4
.IX Item "Test::Moose::More"
Some tests were fragile, but have been fixed. The actual breakage was from the
subtest comment indentation change.
.Sp
No need to upgrade, old versions work fine. Only new versions will install.
.Sp
Fixed in version: 0.025
.IP "Test::FITesque" 4
.IX Item "Test::FITesque"
This was broken by a bugfix to how planning is done. The test was updated after
the bugfix.
.Sp
Fixed in version: 0.04
.IP "Test::Kit" 4
.IX Item "Test::Kit"
Old versions work fine, but would not install because Test::Aggregate was in
the dependency chain. An upgrade should not be needed.
.Sp
Fixed in version: 2.15
.IP "autouse" 4
.IX Item "autouse"
A test broke because it depended on Scalar::Util not being loaded. Test2 loads
Scalar::Util. The test was updated to load Test2 after checking Scalar::Util's
load status.
.Sp
There is no need to upgrade if you already have it installed.
.Sp
Fixed in version: 1.11
.SS "\s-1NEED TO UPGRADE\s0"
.IX Subsection "NEED TO UPGRADE"
.IP "Test::SharedFork" 4
.IX Item "Test::SharedFork"
Old versions need to directly access Test::Builder singleton hash elements. The
latest version on \s-1CPAN\s0 will still do this on old Test::Builder, but will defer
to Test2::IPC on Test2.
.Sp
Fixed in version: 0.35
.IP "Test::Builder::Clutch" 4
.IX Item "Test::Builder::Clutch"
This works by doing overriding methods on the singleton, and directly accessing
hash values on the singleton. A new version has been released that uses the
Test2 \s-1API\s0 to accomplish the same result in a saner way.
.Sp
Fixed in version: 0.07
.IP "Test::Dist::VersionSync" 4
.IX Item "Test::Dist::VersionSync"
This had Test::Builder2 conditionals. This was fixed by removing the
conditionals.
.Sp
Fixed in version: 1.1.4
.IP "Test::Modern" 4
.IX Item "Test::Modern"
This relied on \f(CW\*(C`Test::Builder\->_try()\*(C'\fR which was a private method,
documented as something nobody should use. This was fixed by using a different
tool.
.Sp
Fixed in version: 0.012
.IP "Test::UseAllModules" 4
.IX Item "Test::UseAllModules"
Version 0.14 relied on \f(CW\*(C`Test::Builder\->history\*(C'\fR which was available in
Test::Builder 1.5. Versions 0.12 and 0.13 relied on other Test::Builder
internals.
.Sp
Fixed in version: 0.15
.IP "Test::More::Prefix" 4
.IX Item "Test::More::Prefix"
Worked by applying a role that wrapped \f(CW\*(C`Test::Builder\->_print_comment\*(C'\fR.
Fixed by adding an event filter that modifies the message instead when running
under Test2.
.Sp
Fixed in version: 0.007
.SS "\s-1STILL BROKEN\s0"
.IX Subsection "STILL BROKEN"
.IP "Test::Aggregate" 4
.IX Item "Test::Aggregate"
This distribution directly accesses the hash keys in the Test::Builder
singleton. It also approaches the problem from the wrong angle, please consider
using Test2::Aggregate for similar functionality and Test2::Harness
which allows module preloading at the harness level.
.Sp
Still broken as of version: 0.373
.IP "Test::Wrapper" 4
.IX Item "Test::Wrapper"
This module directly uses hash keys in the Test::Builder singleton. This
module is also obsolete thanks to the benefits of Test2. Use \f(CW\*(C`intercept()\*(C'\fR
from Test2::API to achieve a similar result.
.Sp
Still broken as of version: 0.3.0
.IP "Test::ParallelSubtest" 4
.IX Item "Test::ParallelSubtest"
This module overrides \f(CW\*(C`Test::Builder::subtest()\*(C'\fR and
\&\f(CW\*(C`Test::Builder::done_testing()\*(C'\fR. It also directly accesses hash elements of
the singleton. It has not yet been fixed.
.Sp
Alternatives: Test2::AsyncSubtest and Test2::Workflow (not stable).
.Sp
Still broken as of version: 0.05
.IP "Test::Pretty" 4
.IX Item "Test::Pretty"
See https://github.com/tokuhirom/Test\-Pretty/issues/25
.Sp
The author admits the module is crazy, and he is awaiting a stable release of
something new (Test2) to completely rewrite it in a sane way.
.Sp
Still broken as of version: 0.32
.IP "Net::BitTorrent" 4
.IX Item "Net::BitTorrent"
The tests for this module directly access Test::Builder hash keys. Most, if
not all of these hash keys have public \s-1API\s0 methods that could be used instead
to avoid the problem.
.Sp
Still broken in version: 0.052
.IP "Test::Group" 4
.IX Item "Test::Group"
It monkeypatches Test::Builder, and calls it \*(L"black magic\*(R" in the code.
.Sp
Still broken as of version: 0.20
.IP "Test::Flatten" 4
.IX Item "Test::Flatten"
This modifies the Test::Builder internals in many ways. A better was to
accomplish the goal of this module is to write your own subtest function.
.Sp
Still broken as of version: 0.11
.IP "Log::Dispatch::Config::TestLog" 4
.IX Item "Log::Dispatch::Config::TestLog"
Modifies Test::Builder internals.
.Sp
Still broken as of version: 0.02
.IP "Test::Able" 4
.IX Item "Test::Able"
Modifies Test::Builder internals.
.Sp
Still broken as of version: 0.11
.SH "MAKE ASSERTIONS \-> SEND EVENTS"
.IX Header "MAKE ASSERTIONS -> SEND EVENTS"
.SS "\s-1LEGACY\s0"
.IX Subsection "LEGACY"
.Vb 1
\&    use Test::Builder;
\&
\&    # A majority of tools out there do this:
\&    # my $TB = Test::Builder\->new;
\&    # This works, but has always been wrong, forcing Test::Builder to implement
\&    # subtests as a horrific hack. It also causes problems for tools that try
\&    # to replace the singleton (also discouraged).
\&
\&    sub my_ok($;$) {
\&        my ($bool, $name) = @_;
\&        my $TB = Test::Builder\->new;
\&        $TB\->ok($bool, $name);
\&    }
\&
\&    sub my_diag($) {
\&        my ($msg) = @_;
\&        my $TB = Test::Builder\->new;
\&        $TB\->diag($msg);
\&    }
.Ve
.SS "\s-1TEST2\s0"
.IX Subsection "TEST2"
.Vb 1
\&    use Test2::API qw/context/;
\&
\&    sub my_ok($;$) {
\&        my ($bool, $name) = @_;
\&        my $ctx = context();
\&        $ctx\->ok($bool, $name);
\&        $ctx\->release;
\&    }
\&
\&    sub my_diag($) {
\&        my ($msg) = @_;
\&        my $ctx = context();
\&        $ctx\->diag($msg);
\&        $ctx\->release;
\&    }
.Ve
.PP
The context object has \s-1API\s0 compatible implementations of the following methods:
.ie n .IP "ok($bool, $name)" 4
.el .IP "ok($bool, \f(CW$name\fR)" 4
.IX Item "ok($bool, $name)"
.PD 0
.IP "diag(@messages)" 4
.IX Item "diag(@messages)"
.IP "note(@messages)" 4
.IX Item "note(@messages)"
.ie n .IP "subtest($name, $code)" 4
.el .IP "subtest($name, \f(CW$code\fR)" 4
.IX Item "subtest($name, $code)"
.PD
.PP
If you are looking for helpers with \f(CW\*(C`is\*(C'\fR, \f(CW\*(C`like\*(C'\fR, and others, see
Test2::Suite.
.SH "WRAP EXISTING TOOLS"
.IX Header "WRAP EXISTING TOOLS"
.SS "\s-1LEGACY\s0"
.IX Subsection "LEGACY"
.Vb 1
\&    use Test::More;
\&
\&    sub exclusive_ok {
\&        my ($bool1, $bool2, $name) = @_;
\&
\&        # Ensure errors are reported 1 level higher
\&        local $Test::Builder::Level = $Test::Builder::Level + 1;
\&
\&        $ok = $bool1 || $bool2;
\&        $ok &&= !($bool1 && $bool2);
\&        ok($ok, $name);
\&
\&        return $bool;
\&    }
.Ve
.PP
Every single tool in the chain from this, to \f(CW\*(C`ok\*(C'\fR, to anything \f(CW\*(C`ok\*(C'\fR calls
needs to increment the \f(CW$Level\fR variable. When an error occurs Test::Builder
will do a trace to the stack frame determined by \f(CW$Level\fR, and report that
file+line as the one where the error occurred. If you or any other tool you use
forgets to set \f(CW$Level\fR then errors will be reported to the wrong place.
.SS "\s-1TEST2\s0"
.IX Subsection "TEST2"
.Vb 1
\&    use Test::More;
\&
\&    sub exclusive_ok {
\&        my ($bool1, $bool2, $name) = @_;
\&
\&        # Grab and store the context, even if you do not need to use it
\&        # directly.
\&        my $ctx = context();
\&
\&        $ok = $bool1 || $bool2;
\&        $ok &&= !($bool1 && $bool2);
\&        ok($ok, $name);
\&
\&        $ctx\->release;
\&        return $bool;
\&    }
.Ve
.PP
Instead of using \f(CW$Level\fR to perform a backtrace, Test2 uses a context
object. In this sample you create a context object and store it. This locks the
context (errors report 1 level up from here) for all wrapped tools to find. You
do not need to use the context object, but you do need to store it in a
variable. Once the sub ends the \f(CW$ctx\fR variable is destroyed which lets future
tools find their own.
.SH "USING UTF8"
.IX Header "USING UTF8"
.SS "\s-1LEGACY\s0"
.IX Subsection "LEGACY"
.Vb 3
\&    # Set the mode BEFORE anything loads Test::Builder
\&    use open \*(Aq:std\*(Aq, \*(Aq:encoding(utf8)\*(Aq;
\&    use Test::More;
.Ve
.PP
Or
.PP
.Vb 5
\&    # Modify the filehandles
\&    my $builder = Test::More\->builder;
\&    binmode $builder\->output,         ":encoding(utf8)";
\&    binmode $builder\->failure_output, ":encoding(utf8)";
\&    binmode $builder\->todo_output,    ":encoding(utf8)";
.Ve
.SS "\s-1TEST2\s0"
.IX Subsection "TEST2"
.Vb 1
\&    use Test2::API qw/test2_stack/;
\&
\&    test2_stack\->top\->format\->encoding(\*(Aqutf8\*(Aq);
.Ve
.PP
Though a much better way is to use the Test2::Plugin::UTF8 plugin, which is
part of Test2::Suite.
.SH "AUTHORS, CONTRIBUTORS AND REVIEWERS"
.IX Header "AUTHORS, CONTRIBUTORS AND REVIEWERS"
The following people have all contributed to this document in some way, even if
only for review.
.IP "Chad Granum (\s-1EXODIST\s0) <exodist@cpan.org>" 4
.IX Item "Chad Granum (EXODIST) <exodist@cpan.org>"
.SH "SOURCE"
.IX Header "SOURCE"
The source code repository for Test2 can be found at
\&\fIhttp://github.com/Test\-More/test\-more/\fR.
.SH "MAINTAINER"
.IX Header "MAINTAINER"
.IP "Chad Granum <exodist@cpan.org>" 4
.IX Item "Chad Granum <exodist@cpan.org>"
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2020 Chad Granum <exodist@cpan.org>.
.PP
This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
.PP
See \fIhttp://www.perl.com/perl/misc/Artistic.html\fR