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.\" ========================================================================
.\"
.IX Title "Test2::API 3pm"
.TH Test2::API 3pm 2023-11-28 "perl v5.38.2" "Perl Programmers Reference Guide"
.\" 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
Test2::API \- Primary interface for writing Test2 based testing tools.
.SH "***INTERNALS NOTE***"
.IX Header "***INTERNALS NOTE***"
\&\fBThe internals of this package are subject to change at any time!\fR The public
methods provided will not change in backwards-incompatible ways (once there is
a stable release), but the underlying implementation details might.
\&\fBDo not break encapsulation here!\fR
.PP
Currently the implementation is to create a single instance of the
Test2::API::Instance Object. All class methods defer to the single
instance. There is no public access to the singleton, and that is intentional.
The class methods provided by this package provide the only functionality
publicly exposed.
.PP
This is done primarily to avoid the problems Test::Builder had by exposing its
singleton. We do not want anyone to replace this singleton, rebless it, or
directly muck with its internals. If you need to do something and cannot
because of the restrictions placed here, then please report it as an issue. If
possible, we will create a way for you to implement your functionality without
exposing things that should not be exposed.
.SH DESCRIPTION
.IX Header "DESCRIPTION"
This package exports all the functions necessary to write and/or verify testing
tools. Using these building blocks you can begin writing test tools very
quickly. You are also provided with tools that help you to test the tools you
write.
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.SS "WRITING A TOOL"
.IX Subsection "WRITING A TOOL"
The \f(CWcontext()\fR method is your primary interface into the Test2 framework.
.PP
.Vb 2
\&    package My::Ok;
\&    use Test2::API qw/context/;
\&
\&    our @EXPORT = qw/my_ok/;
\&    use base \*(AqExporter\*(Aq;
\&
\&    # Just like ok() from Test::More
\&    sub my_ok($;$) {
\&        my ($bool, $name) = @_;
\&        my $ctx = context(); # Get a context
\&        $ctx\->ok($bool, $name);
\&        $ctx\->release; # Release the context
\&        return $bool;
\&    }
.Ve
.PP
See Test2::API::Context for a list of methods available on the context object.
.SS "TESTING YOUR TOOLS"
.IX Subsection "TESTING YOUR TOOLS"
The \f(CW\*(C`intercept { ... }\*(C'\fR tool lets you temporarily intercept all events
generated by the test system:
.PP
.Vb 1
\&    use Test2::API qw/intercept/;
\&
\&    use My::Ok qw/my_ok/;
\&
\&    my $events = intercept {
\&        # These events are not displayed
\&        my_ok(1, "pass");
\&        my_ok(0, "fail");
\&    };
.Ve
.PP
As of version 1.302178 this now returns an arrayref that is also an instance of
Test2::API::InterceptResult. See the Test2::API::InterceptResult
documentation for details on how to best use it.
.SS "OTHER API FUNCTIONS"
.IX Subsection "OTHER API FUNCTIONS"
.Vb 10
\&    use Test2::API qw{
\&        test2_init_done
\&        test2_stack
\&        test2_set_is_end
\&        test2_get_is_end
\&        test2_ipc
\&        test2_formatter_set
\&        test2_formatter
\&        test2_is_testing_done
\&    };
\&
\&    my $init  = test2_init_done();
\&    my $stack = test2_stack();
\&    my $ipc   = test2_ipc();
\&
\&    test2_formatter_set($FORMATTER)
\&    my $formatter = test2_formatter();
\&
\&    ... And others ...
.Ve
.SH "MAIN API EXPORTS"
.IX Header "MAIN API EXPORTS"
All exports are optional. You must specify subs to import.
.PP
.Vb 1
\&    use Test2::API qw/context intercept run_subtest/;
.Ve
.PP
This is the list of exports that are most commonly needed. If you are simply
writing a tool, then this is probably all you need. If you need something and
you cannot find it here, then you can also look at "OTHER API EXPORTS".
.PP
These exports lack the 'test2_' prefix because of how important/common they
are. Exports in the "OTHER API EXPORTS" section have the 'test2_' prefix to
ensure they stand out.
.SS context(...)
.IX Subsection "context(...)"
Usage:
.ie n .IP "$ctx = \fBcontext()\fR" 4
.el .IP "\f(CW$ctx\fR = \fBcontext()\fR" 4
.IX Item "$ctx = context()"
.PD 0
.ie n .IP "$ctx = context(%params)" 4
.el .IP "\f(CW$ctx\fR = context(%params)" 4
.IX Item "$ctx = context(%params)"
.PD
.PP
The \f(CWcontext()\fR function will always return the current context. If
there is already a context active, it will be returned. If there is not an
active context, one will be generated. When a context is generated it will
default to using the file and line number where the currently running sub was
called from.
.PP
Please see "CRITICAL DETAILS" in Test2::API::Context for important rules about
what you can and cannot do with a context once it is obtained.
.PP
\&\fBNote\fR This function will throw an exception if you ignore the context object
it returns.
.PP
\&\fBNote\fR On perls 5.14+ a depth check is used to insure there are no context
leaks. This cannot be safely done on older perls due to
<https://rt.perl.org/Public/Bug/Display.html?id=127774>
You can forcefully enable it either by setting \f(CW\*(C`$ENV{T2_CHECK_DEPTH} = 1\*(C'\fR or
\&\f(CW\*(C`$Test2::API::DO_DEPTH_CHECK = 1\*(C'\fR \fBBEFORE\fR loading Test2::API.
.PP
\fIOPTIONAL PARAMETERS\fR
.IX Subsection "OPTIONAL PARAMETERS"
.PP
All parameters to \f(CW\*(C`context\*(C'\fR are optional.
.ie n .IP "level => $int" 4
.el .IP "level => \f(CW$int\fR" 4
.IX Item "level => $int"
If you must obtain a context in a sub deeper than your entry point you can use
this to tell it how many EXTRA stack frames to look back. If this option is not
provided the default of \f(CW0\fR is used.
.Sp
.Vb 6
\&    sub third_party_tool {
\&        my $sub = shift;
\&        ... # Does not obtain a context
\&        $sub\->();
\&        ...
\&    }
\&
\&    third_party_tool(sub {
\&        my $ctx = context(level => 1);
\&        ...
\&        $ctx\->release;
\&    });
.Ve
.ie n .IP "wrapped => $int" 4
.el .IP "wrapped => \f(CW$int\fR" 4
.IX Item "wrapped => $int"
Use this if you need to write your own tool that wraps a call to \f(CWcontext()\fR
with the intent that it should return a context object.
.Sp
.Vb 7
\&    sub my_context {
\&        my %params = ( wrapped => 0, @_ );
\&        $params{wrapped}++;
\&        my $ctx = context(%params);
\&        ...
\&        return $ctx;
\&    }
\&
\&    sub my_tool {
\&        my $ctx = my_context();
\&        ...
\&        $ctx\->release;
\&    }
.Ve
.Sp
If you do not do this, then tools you call that also check for a context will
notice that the context they grabbed was created at the same stack depth, which
will trigger protective measures that warn you and destroy the existing
context.
.ie n .IP "stack => $stack" 4
.el .IP "stack => \f(CW$stack\fR" 4
.IX Item "stack => $stack"
Normally \f(CWcontext()\fR looks at the global hub stack. If you are maintaining
your own Test2::API::Stack instance you may pass it in to be used
instead of the global one.
.ie n .IP "hub => $hub" 4
.el .IP "hub => \f(CW$hub\fR" 4
.IX Item "hub => $hub"
Use this parameter if you want to obtain the context for a specific hub instead
of whatever one happens to be at the top of the stack.
.IP "on_init => sub { ... }" 4
.IX Item "on_init => sub { ... }"
This lets you provide a callback sub that will be called \fBONLY\fR if your call
to \f(CWcontext()\fR generated a new context. The callback \fBWILL NOT\fR be called if
\&\f(CWcontext()\fR is returning an existing context. The only argument passed into
the callback will be the context object itself.
.Sp
.Vb 2
\&    sub foo {
\&        my $ctx = context(on_init => sub { \*(Aqwill run\*(Aq });
\&
\&        my $inner = sub {
\&            # This callback is not run since we are getting the existing
\&            # context from our parent sub.
\&            my $ctx = context(on_init => sub { \*(Aqwill NOT run\*(Aq });
\&            $ctx\->release;
\&        }
\&        $inner\->();
\&
\&        $ctx\->release;
\&    }
.Ve
.IP "on_release => sub { ... }" 4
.IX Item "on_release => sub { ... }"
This lets you provide a callback sub that will be called when the context
instance is released. This callback will be added to the returned context even
if an existing context is returned. If multiple calls to context add callbacks,
then all will be called in reverse order when the context is finally released.
.Sp
.Vb 2
\&    sub foo {
\&        my $ctx = context(on_release => sub { \*(Aqwill run second\*(Aq });
\&
\&        my $inner = sub {
\&            my $ctx = context(on_release => sub { \*(Aqwill run first\*(Aq });
\&
\&            # Neither callback runs on this release
\&            $ctx\->release;
\&        }
\&        $inner\->();
\&
\&        # Both callbacks run here.
\&        $ctx\->release;
\&    }
.Ve
.SS release($;$)
.IX Subsection "release($;$)"
Usage:
.ie n .IP "release $ctx;" 4
.el .IP "release \f(CW$ctx\fR;" 4
.IX Item "release $ctx;"
.PD 0
.ie n .IP "release $ctx, ...;" 4
.el .IP "release \f(CW$ctx\fR, ...;" 4
.IX Item "release $ctx, ...;"
.PD
.PP
This is intended as a shortcut that lets you release your context and return a
value in one statement. This function will get your context, and an optional
return value. It will release your context, then return your value. Scalar
context is always assumed.
.PP
.Vb 3
\&    sub tool {
\&        my $ctx = context();
\&        ...
\&
\&        return release $ctx, 1;
\&    }
.Ve
.PP
This tool is most useful when you want to return the value you get from calling
a function that needs to see the current context:
.PP
.Vb 4
\&    my $ctx = context();
\&    my $out = some_tool(...);
\&    $ctx\->release;
\&    return $out;
.Ve
.PP
We can combine the last 3 lines of the above like so:
.PP
.Vb 2
\&    my $ctx = context();
\&    release $ctx, some_tool(...);
.Ve
.SS context_do(&;@)
.IX Subsection "context_do(&;@)"
Usage:
.PP
.Vb 3
\&    sub my_tool {
\&        context_do {
\&            my $ctx = shift;
\&
\&            my (@args) = @_;
\&
\&            $ctx\->ok(1, "pass");
\&
\&            ...
\&
\&            # No need to call $ctx\->release, done for you on scope exit.
\&        } @_;
\&    }
.Ve
.PP
Using this inside your test tool takes care of a lot of boilerplate for you. It
will ensure a context is acquired. It will capture and rethrow any exception. It
will insure the context is released when you are done. It preserves the
subroutine call context (array, scalar, void).
.PP
This is the safest way to write a test tool. The only two downsides to this are a
slight performance decrease, and some extra indentation in your source. If the
indentation is a problem for you then you can take a peek at the next section.
.SS no_context(&;$)
.IX Subsection "no_context(&;$)"
Usage:
.IP "no_context { ... };" 4
.IX Item "no_context { ... };"
.PD 0
.ie n .IP "no_context { ... } $hid;" 4
.el .IP "no_context { ... } \f(CW$hid\fR;" 4
.IX Item "no_context { ... } $hid;"
.PD
.Vb 4
\&    sub my_tool(&) {
\&        my $code = shift;
\&        my $ctx = context();
\&        ...
\&
\&        no_context {
\&            # Things in here will not see our current context, they get a new
\&            # one.
\&
\&            $code\->();
\&        };
\&
\&        ...
\&        $ctx\->release;
\&    };
.Ve
.PP
This tool will hide a context for the provided block of code. This means any
tools run inside the block will get a completely new context if they acquire
one. The new context will be inherited by tools nested below the one that
acquired it.
.PP
This will normally hide the current context for the top hub. If you need to
hide the context for a different hub you can pass in the optional \f(CW$hid\fR
parameter.
.SS intercept(&)
.IX Subsection "intercept(&)"
Usage:
.PP
.Vb 5
\&    my $events = intercept {
\&        ok(1, "pass");
\&        ok(0, "fail");
\&        ...
\&    };
.Ve
.PP
This function takes a codeblock as its only argument, and it has a prototype.
It will execute the codeblock, intercepting any generated events in the
process. It will return an array reference with all the generated event
objects. All events should be subclasses of Test2::Event.
.PP
As of version 1.302178 the events array that is returned is blssed as an
Test2::API::InterceptResult instance. Test2::API::InterceptResult
Provides a helpful interface for filtering and/or inspecting the events list
overall, or individual events within the list.
.PP
This is intended to help you test your test code. This is not intended for
people simply writing tests.
.SS run_subtest(...)
.IX Subsection "run_subtest(...)"
Usage:
.PP
.Vb 1
\&    run_subtest($NAME, \e&CODE, $BUFFERED, @ARGS)
\&
\&    # or
\&
\&    run_subtest($NAME, \e&CODE, \e%PARAMS, @ARGS)
.Ve
.PP
This will run the provided codeblock with the args in \f(CW@args\fR. This codeblock
will be run as a subtest. A subtest is an isolated test state that is condensed
into a single Test2::Event::Subtest event, which contains all events
generated inside the subtest.
.PP
\fIARGUMENTS:\fR
.IX Subsection "ARGUMENTS:"
.ie n .IP $NAME 4
.el .IP \f(CW$NAME\fR 4
.IX Item "$NAME"
The name of the subtest.
.IP \e&CODE 4
.IX Item "&CODE"
The code to run inside the subtest.
.ie n .IP "$BUFFERED or \e%PARAMS" 4
.el .IP "\f(CW$BUFFERED\fR or \e%PARAMS" 4
.IX Item "$BUFFERED or %PARAMS"
If this is a simple scalar then it will be treated as a boolean for the
\&'buffered' setting. If this is a hash reference then it will be used as a
parameters hash. The param hash will be used for hub construction (with the
specified keys removed).
.Sp
Keys that are removed and used by run_subtest:
.RS 4
.ie n .IP "'buffered' => $bool" 4
.el .IP "'buffered' => \f(CW$bool\fR" 4
.IX Item "'buffered' => $bool"
Toggle buffered status.
.ie n .IP "'inherit_trace' => $bool" 4
.el .IP "'inherit_trace' => \f(CW$bool\fR" 4
.IX Item "'inherit_trace' => $bool"
Normally the subtest hub is pushed and the sub is allowed to generate its own
root context for the hub. When this setting is turned on a root context will be
created for the hub that shares the same trace as the current context.
.Sp
Set this to true if your tool is producing subtests without user-specified
subs.
.ie n .IP "'no_fork' => $bool" 4
.el .IP "'no_fork' => \f(CW$bool\fR" 4
.IX Item "'no_fork' => $bool"
Defaults to off. Normally forking inside a subtest will actually fork the
subtest, resulting in 2 final subtest events. This parameter will turn off that
behavior, only the original process/thread will return a final subtest event.
.RE
.RS 4
.RE
.ie n .IP @ARGS 4
.el .IP \f(CW@ARGS\fR 4
.IX Item "@ARGS"
Any extra arguments you want passed into the subtest code.
.PP
\fIBUFFERED VS UNBUFFERED (OR STREAMED)\fR
.IX Subsection "BUFFERED VS UNBUFFERED (OR STREAMED)"
.PP
Normally all events inside and outside a subtest are sent to the formatter
immediately by the hub. Sometimes it is desirable to hold off sending events
within a subtest until the subtest is complete. This usually depends on the
formatter being used.
.IP "Things not effected by this flag" 4
.IX Item "Things not effected by this flag"
In both cases events are generated and stored in an array. This array is
eventually used to populate the \f(CW\*(C`subevents\*(C'\fR attribute on the
Test2::Event::Subtest event that is generated at the end of the subtest.
This flag has no effect on this part, it always happens.
.Sp
At the end of the subtest, the final Test2::Event::Subtest event is sent to
the formatter.
.IP "Things that are effected by this flag" 4
.IX Item "Things that are effected by this flag"
The \f(CW\*(C`buffered\*(C'\fR attribute of the Test2::Event::Subtest event will be set to
the value of this flag. This means any formatter, listener, etc which looks at
the event will know if it was buffered.
.IP "Things that are formatter dependant" 4
.IX Item "Things that are formatter dependant"
Events within a buffered subtest may or may not be sent to the formatter as
they happen. If a formatter fails to specify then the default is to \fBNOT SEND\fR
the events as they are generated, instead the formatter can pull them from the
\&\f(CW\*(C`subevents\*(C'\fR attribute.
.Sp
A formatter can specify by implementing the \f(CWhide_buffered()\fR method. If this
method returns true then events generated inside a buffered subtest will not be
sent independently of the final subtest event.
.PP
An example of how this is used is the Test2::Formatter::TAP formatter. For
unbuffered subtests the events are rendered as they are generated. At the end
of the subtest, the final subtest event is rendered, but the \f(CW\*(C`subevents\*(C'\fR
attribute is ignored. For buffered subtests the opposite occurs, the events are
NOT rendered as they are generated, instead the \f(CW\*(C`subevents\*(C'\fR attribute is used
to render them all at once. This is useful when running subtests tests in
parallel, since without it the output from subtests would be interleaved
together.
.SH "OTHER API EXPORTS"
.IX Header "OTHER API EXPORTS"
Exports in this section are not commonly needed. These all have the 'test2_'
prefix to help ensure they stand out. You should look at the "MAIN API
EXPORTS" section before looking here. This section is one where "Great power
comes with great responsibility". It is possible to break things badly if you
are not careful with these.
.PP
All exports are optional. You need to list which ones you want at import time:
.PP
.Vb 1
\&    use Test2::API qw/test2_init_done .../;
.Ve
.SS "STATUS AND INITIALIZATION STATE"
.IX Subsection "STATUS AND INITIALIZATION STATE"
These provide access to internal state and object instances.
.ie n .IP "$bool = \fBtest2_init_done()\fR" 4
.el .IP "\f(CW$bool\fR = \fBtest2_init_done()\fR" 4
.IX Item "$bool = test2_init_done()"
This will return true if the stack and IPC instances have already been
initialized. It will return false if they have not. Init happens as late as
possible. It happens as soon as a tool requests the IPC instance, the
formatter, or the stack.
.ie n .IP "$bool = \fBtest2_load_done()\fR" 4
.el .IP "\f(CW$bool\fR = \fBtest2_load_done()\fR" 4
.IX Item "$bool = test2_load_done()"
This will simply return the boolean value of the loaded flag. If Test2 has
finished loading this will be true, otherwise false. Loading is considered
complete the first time a tool requests a context.
.IP \fBtest2_set_is_end()\fR 4
.IX Item "test2_set_is_end()"
.PD 0
.IP test2_set_is_end($bool) 4
.IX Item "test2_set_is_end($bool)"
.PD
This is used to toggle Test2's belief that the END phase has already started.
With no arguments this will set it to true. With arguments it will set it to
the first argument's value.
.Sp
This is used to prevent the use of \f(CWcaller()\fR in END blocks which can cause
segfaults. This is only necessary in some persistent environments that may have
multiple END phases.
.ie n .IP "$bool = \fBtest2_get_is_end()\fR" 4
.el .IP "\f(CW$bool\fR = \fBtest2_get_is_end()\fR" 4
.IX Item "$bool = test2_get_is_end()"
Check if Test2 believes it is the END phase.
.ie n .IP "$stack = \fBtest2_stack()\fR" 4
.el .IP "\f(CW$stack\fR = \fBtest2_stack()\fR" 4
.IX Item "$stack = test2_stack()"
This will return the global Test2::API::Stack instance. If this has not
yet been initialized it will be initialized now.
.ie n .IP "$bool = \fBtest2_is_testing_done()\fR" 4
.el .IP "\f(CW$bool\fR = \fBtest2_is_testing_done()\fR" 4
.IX Item "$bool = test2_is_testing_done()"
This will return true if testing is complete and no other events should be
sent. This is useful in things like warning handlers where you might want to
turn warnings into events, but need them to start acting like normal warnings
when testing is done.
.Sp
.Vb 2
\&    $SIG{_\|_WARN_\|_} = sub {
\&        my ($warning) = @_;
\&
\&        if (test2_is_testing_done()) {
\&            warn @_;
\&        }
\&        else {
\&            my $ctx = context();
\&            ...
\&            $ctx\->release
\&        }
\&    }
.Ve
.IP test2_ipc_disable 4
.IX Item "test2_ipc_disable"
Disable IPC.
.ie n .IP "$bool = test2_ipc_diabled" 4
.el .IP "\f(CW$bool\fR = test2_ipc_diabled" 4
.IX Item "$bool = test2_ipc_diabled"
Check if IPC is disabled.
.IP \fBtest2_ipc_wait_enable()\fR 4
.IX Item "test2_ipc_wait_enable()"
.PD 0
.IP \fBtest2_ipc_wait_disable()\fR 4
.IX Item "test2_ipc_wait_disable()"
.ie n .IP "$bool = \fBtest2_ipc_wait_enabled()\fR" 4
.el .IP "\f(CW$bool\fR = \fBtest2_ipc_wait_enabled()\fR" 4
.IX Item "$bool = test2_ipc_wait_enabled()"
.PD
These can be used to turn IPC waiting on and off, or check the current value of
the flag.
.Sp
Waiting is turned on by default. Waiting will cause the parent process/thread
to wait until all child processes and threads are finished before exiting. You
will almost never want to turn this off.
.ie n .IP "$bool = \fBtest2_no_wait()\fR" 4
.el .IP "\f(CW$bool\fR = \fBtest2_no_wait()\fR" 4
.IX Item "$bool = test2_no_wait()"
.PD 0
.IP test2_no_wait($bool) 4
.IX Item "test2_no_wait($bool)"
.PD
\&\fBDISCOURAGED\fR: This is a confusing interface, it is better to use
\&\f(CWtest2_ipc_wait_enable()\fR, \f(CWtest2_ipc_wait_disable()\fR and
\&\f(CWtest2_ipc_wait_enabled()\fR.
.Sp
This can be used to get/set the no_wait status. Waiting is turned on by
default. Waiting will cause the parent process/thread to wait until all child
processes and threads are finished before exiting. You will almost never want
to turn this off.
.ie n .IP "$fh = \fBtest2_stdout()\fR" 4
.el .IP "\f(CW$fh\fR = \fBtest2_stdout()\fR" 4
.IX Item "$fh = test2_stdout()"
.PD 0
.ie n .IP "$fh = \fBtest2_stderr()\fR" 4
.el .IP "\f(CW$fh\fR = \fBtest2_stderr()\fR" 4
.IX Item "$fh = test2_stderr()"
.PD
These functions return the filehandles that test output should be written to.
They are primarily useful when writing a custom formatter and code that turns
events into actual output (TAP, etc.).  They will return a dupe of the original
filehandles that formatted output can be sent to regardless of whatever state
the currently running test may have left STDOUT and STDERR in.
.IP \fBtest2_reset_io()\fR 4
.IX Item "test2_reset_io()"
Re-dupe the internal filehandles returned by \f(CWtest2_stdout()\fR and
\&\f(CWtest2_stderr()\fR from the current STDOUT and STDERR.  You shouldn't need to do
this except in very peculiar situations (for example, you're testing a new
formatter and you need control over where the formatter is sending its output.)
.SS "BEHAVIOR HOOKS"
.IX Subsection "BEHAVIOR HOOKS"
These are hooks that allow you to add custom behavior to actions taken by Test2
and tools built on top of it.
.IP "test2_add_callback_exit(sub { ... })" 4
.IX Item "test2_add_callback_exit(sub { ... })"
This can be used to add a callback that is called after all testing is done. This
is too late to add additional results, the main use of this callback is to set the
exit code.
.Sp
.Vb 6
\&    test2_add_callback_exit(
\&        sub {
\&            my ($context, $exit, \e$new_exit) = @_;
\&            ...
\&        }
\&    );
.Ve
.Sp
The \f(CW$context\fR passed in will be an instance of Test2::API::Context. The
\&\f(CW$exit\fR argument will be the original exit code before anything modified it.
\&\f(CW$$new_exit\fR is a reference to the new exit code. You may modify this to
change the exit code. Please note that \f(CW$$new_exit\fR may already be different
from \f(CW$exit\fR
.IP "test2_add_callback_post_load(sub { ... })" 4
.IX Item "test2_add_callback_post_load(sub { ... })"
Add a callback that will be called when Test2 is finished loading. This
means the callback will be run once, the first time a context is obtained.
If Test2 has already finished loading then the callback will be run immediately.
.IP "test2_add_callback_testing_done(sub { ... })" 4
.IX Item "test2_add_callback_testing_done(sub { ... })"
This adds your coderef as a follow-up to the root hub after Test2 is finished loading.
.Sp
This is essentially a helper to do the following:
.Sp
.Vb 4
\&    test2_add_callback_post_load(sub {
\&        my $stack = test2_stack();
\&        $stack\->top; # Insure we have a hub
\&        my ($hub) = Test2::API::test2_stack\->all;
\&
\&        $hub\->set_active(1);
\&
\&        $hub\->follow_up(sub { ... }); # <\-\- Your coderef here
\&    });
.Ve
.IP "test2_add_callback_context_acquire(sub { ... })" 4
.IX Item "test2_add_callback_context_acquire(sub { ... })"
Add a callback that will be called every time someone tries to acquire a
context. This will be called on EVERY call to \f(CWcontext()\fR. It gets a single
argument, a reference to the hash of parameters being used the construct the
context. This is your chance to change the parameters by directly altering the
hash.
.Sp
.Vb 4
\&    test2_add_callback_context_acquire(sub {
\&        my $params = shift;
\&        $params\->{level}++;
\&    });
.Ve
.Sp
This is a very scary API function. Please do not use this unless you need to.
This is here for Test::Builder and backwards compatibility. This has you
directly manipulate the hash instead of returning a new one for performance
reasons.
.IP "test2_add_callback_context_init(sub { ... })" 4
.IX Item "test2_add_callback_context_init(sub { ... })"
Add a callback that will be called every time a new context is created. The
callback will receive the newly created context as its only argument.
.IP "test2_add_callback_context_release(sub { ... })" 4
.IX Item "test2_add_callback_context_release(sub { ... })"
Add a callback that will be called every time a context is released. The
callback will receive the released context as its only argument.
.IP "test2_add_callback_pre_subtest(sub { ... })" 4
.IX Item "test2_add_callback_pre_subtest(sub { ... })"
Add a callback that will be called every time a subtest is going to be
run. The callback will receive the subtest name, coderef, and any
arguments.
.ie n .IP "@list = \fBtest2_list_context_acquire_callbacks()\fR" 4
.el .IP "\f(CW@list\fR = \fBtest2_list_context_acquire_callbacks()\fR" 4
.IX Item "@list = test2_list_context_acquire_callbacks()"
Return all the context acquire callback references.
.ie n .IP "@list = \fBtest2_list_context_init_callbacks()\fR" 4
.el .IP "\f(CW@list\fR = \fBtest2_list_context_init_callbacks()\fR" 4
.IX Item "@list = test2_list_context_init_callbacks()"
Returns all the context init callback references.
.ie n .IP "@list = \fBtest2_list_context_release_callbacks()\fR" 4
.el .IP "\f(CW@list\fR = \fBtest2_list_context_release_callbacks()\fR" 4
.IX Item "@list = test2_list_context_release_callbacks()"
Returns all the context release callback references.
.ie n .IP "@list = \fBtest2_list_exit_callbacks()\fR" 4
.el .IP "\f(CW@list\fR = \fBtest2_list_exit_callbacks()\fR" 4
.IX Item "@list = test2_list_exit_callbacks()"
Returns all the exit callback references.
.ie n .IP "@list = \fBtest2_list_post_load_callbacks()\fR" 4
.el .IP "\f(CW@list\fR = \fBtest2_list_post_load_callbacks()\fR" 4
.IX Item "@list = test2_list_post_load_callbacks()"
Returns all the post load callback references.
.ie n .IP "@list = \fBtest2_list_pre_subtest_callbacks()\fR" 4
.el .IP "\f(CW@list\fR = \fBtest2_list_pre_subtest_callbacks()\fR" 4
.IX Item "@list = test2_list_pre_subtest_callbacks()"
Returns all the pre-subtest callback references.
.IP "test2_add_uuid_via(sub { ... })" 4
.IX Item "test2_add_uuid_via(sub { ... })"
.PD 0
.ie n .IP "$sub = \fBtest2_add_uuid_via()\fR" 4
.el .IP "\f(CW$sub\fR = \fBtest2_add_uuid_via()\fR" 4
.IX Item "$sub = test2_add_uuid_via()"
.PD
This allows you to provide a UUID generator. If provided UUIDs will be attached
to all events, hubs, and contexts. This is useful for storing, tracking, and
linking these objects.
.Sp
The sub you provide should always return a unique identifier. Most things will
expect a proper UUID string, however nothing in Test2::API enforces this.
.Sp
The sub will receive exactly 1 argument, the type of thing being tagged
\&'context', 'hub', or 'event'. In the future additional things may be tagged, in
which case new strings will be passed in. These are purely informative, you can
(and usually should) ignore them.
.SS "IPC AND CONCURRENCY"
.IX Subsection "IPC AND CONCURRENCY"
These let you access, or specify, the IPC system internals.
.ie n .IP "$bool = \fBtest2_has_ipc()\fR" 4
.el .IP "\f(CW$bool\fR = \fBtest2_has_ipc()\fR" 4
.IX Item "$bool = test2_has_ipc()"
Check if IPC is enabled.
.ie n .IP "$ipc = \fBtest2_ipc()\fR" 4
.el .IP "\f(CW$ipc\fR = \fBtest2_ipc()\fR" 4
.IX Item "$ipc = test2_ipc()"
This will return the global Test2::IPC::Driver instance. If this has not yet
been initialized it will be initialized now.
.IP test2_ipc_add_driver($DRIVER) 4
.IX Item "test2_ipc_add_driver($DRIVER)"
Add an IPC driver to the list. This will add the driver to the start of the
list.
.ie n .IP "@drivers = \fBtest2_ipc_drivers()\fR" 4
.el .IP "\f(CW@drivers\fR = \fBtest2_ipc_drivers()\fR" 4
.IX Item "@drivers = test2_ipc_drivers()"
Get the list of IPC drivers.
.ie n .IP "$bool = \fBtest2_ipc_polling()\fR" 4
.el .IP "\f(CW$bool\fR = \fBtest2_ipc_polling()\fR" 4
.IX Item "$bool = test2_ipc_polling()"
Check if polling is enabled.
.IP \fBtest2_ipc_enable_polling()\fR 4
.IX Item "test2_ipc_enable_polling()"
Turn on polling. This will cull events from other processes and threads every
time a context is created.
.IP \fBtest2_ipc_disable_polling()\fR 4
.IX Item "test2_ipc_disable_polling()"
Turn off IPC polling.
.IP \fBtest2_ipc_enable_shm()\fR 4
.IX Item "test2_ipc_enable_shm()"
Legacy, this is currently a no-op that returns 0;
.IP test2_ipc_set_pending($uniq_val) 4
.IX Item "test2_ipc_set_pending($uniq_val)"
Tell other processes and events that an event is pending. \f(CW$uniq_val\fR should
be a unique value no other thread/process will generate.
.Sp
\&\fBNote:\fR After calling this \f(CWtest2_ipc_get_pending()\fR will return 1. This is
intentional, and not avoidable.
.ie n .IP "$pending = \fBtest2_ipc_get_pending()\fR" 4
.el .IP "\f(CW$pending\fR = \fBtest2_ipc_get_pending()\fR" 4
.IX Item "$pending = test2_ipc_get_pending()"
This returns \-1 if there is no way to check (assume yes)
.Sp
This returns 0 if there are (most likely) no pending events.
.Sp
This returns 1 if there are (likely) pending events. Upon return it will reset,
nothing else will be able to see that there were pending events.
.ie n .IP "$timeout = \fBtest2_ipc_get_timeout()\fR" 4
.el .IP "\f(CW$timeout\fR = \fBtest2_ipc_get_timeout()\fR" 4
.IX Item "$timeout = test2_ipc_get_timeout()"
.PD 0
.IP test2_ipc_set_timeout($timeout) 4
.IX Item "test2_ipc_set_timeout($timeout)"
.PD
Get/Set the timeout value for the IPC system. This timeout is how long the IPC
system will wait for child processes and threads to finish before aborting.
.Sp
The default value is \f(CW30\fR seconds.
.SS "MANAGING FORMATTERS"
.IX Subsection "MANAGING FORMATTERS"
These let you access, or specify, the formatters that can/should be used.
.ie n .IP "$formatter = test2_formatter" 4
.el .IP "\f(CW$formatter\fR = test2_formatter" 4
.IX Item "$formatter = test2_formatter"
This will return the global formatter class. This is not an instance. By
default the formatter is set to Test2::Formatter::TAP.
.Sp
You can override this default using the \f(CW\*(C`T2_FORMATTER\*(C'\fR environment variable.
.Sp
Normally 'Test2::Formatter::' is prefixed to the value in the
environment variable:
.Sp
.Vb 2
\&    $ T2_FORMATTER=\*(AqTAP\*(Aq perl test.t     # Use the Test2::Formatter::TAP formatter
\&    $ T2_FORMATTER=\*(AqFoo\*(Aq perl test.t     # Use the Test2::Formatter::Foo formatter
.Ve
.Sp
If you want to specify a full module name you use the '+' prefix:
.Sp
.Vb 1
\&    $ T2_FORMATTER=\*(Aq+Foo::Bar\*(Aq perl test.t     # Use the Foo::Bar formatter
.Ve
.IP test2_formatter_set($class_or_instance) 4
.IX Item "test2_formatter_set($class_or_instance)"
Set the global formatter class. This can only be set once. \fBNote:\fR This will
override anything specified in the 'T2_FORMATTER' environment variable.
.ie n .IP "@formatters = \fBtest2_formatters()\fR" 4
.el .IP "\f(CW@formatters\fR = \fBtest2_formatters()\fR" 4
.IX Item "@formatters = test2_formatters()"
Get a list of all loaded formatters.
.IP test2_formatter_add($class_or_instance) 4
.IX Item "test2_formatter_add($class_or_instance)"
Add a formatter to the list. Last formatter added is used at initialization. If
this is called after initialization a warning will be issued.
.SH "OTHER EXAMPLES"
.IX Header "OTHER EXAMPLES"
See the \f(CW\*(C`/Examples/\*(C'\fR directory included in this distribution.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
Test2::API::Context \- Detailed documentation of the context object.
.PP
Test2::IPC \- The IPC system used for threading/fork support.
.PP
Test2::Formatter \- Formatters such as TAP live here.
.PP
Test2::Event \- Events live in this namespace.
.PP
Test2::Hub \- All events eventually funnel through a hub. Custom hubs are how
\&\f(CWintercept()\fR and \f(CWrun_subtest()\fR are implemented.
.SH MAGIC
.IX Header "MAGIC"
This package has an END block. This END block is responsible for setting the
exit code based on the test results. This end block also calls the callbacks that
can be added to this package.
.SH SOURCE
.IX Header "SOURCE"
The source code repository for Test2 can be found at
\&\fIhttp://github.com/Test\-More/test\-more/\fR.
.SH MAINTAINERS
.IX Header "MAINTAINERS"
.IP "Chad Granum <exodist@cpan.org>" 4
.IX Item "Chad Granum <exodist@cpan.org>"
.SH AUTHORS
.IX Header "AUTHORS"
.PD 0
.IP "Chad Granum <exodist@cpan.org>" 4
.IX Item "Chad Granum <exodist@cpan.org>"
.PD
.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://dev.perl.org/licenses/\fR