# Test2::API::InterceptResult - man - phpman

## NAME
    [Test2::API::InterceptResult](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult/markdown) - Representation of a list of events.

## DESCRIPTION
    This class represents a list of events, normally obtained using "intercept()" from [Test2::API](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI/markdown).

    This class is intended for people who with to verify the results of test tools they write.

    This class provides methods to normalize, summarize, or map the list of events. The output of
    these operations makes verifying your testing tools and the events they generate significantly
    easier. In most cases this spares you from needing a deep understanding of the event/facet
    model.

## SYNOPSIS
    Usually you get an instance of this class when you use "intercept()" from [Test2::API](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI/markdown).

        use [Test2::V0](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AV0/markdown);
        use [Test2::API](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI/markdown) qw/intercept/;

        my $events = intercept {
            ok(1, "pass");
            ok(0, "fail");
            todo "broken" => sub { ok(0, "fixme") };
            plan 3;
        };

        # This is typically the most useful construct
        # squash_info() merges assertions and diagnostics that are associated
        #   (and returns a new instance with the modifications)
        # flatten() condenses the facet data into the key details for each event
        #   (and returns those structures in an arrayref)
        is(
            $events->squash_info->flatten(),
            [
                {
                    causes_failure => 0,

                    name => 'pass',
                    pass => 1,

                    trace_file => 'xxx.t',
                    trace_line => 5,
                },
                {
                    causes_failure => 1,

                    name => 'fail',
                    pass => 0,

                    trace_file => 'xxx.t',
                    trace_line => 6,

                    # There can be more than one diagnostics message so this is
                    # always an array when present.
                    diag => ["Failed test 'fail'\nat xxx.t line 6."],
                },
                {
                    causes_failure => 0,

                    name => 'fixme',
                    pass => 0,

                    trace_file => 'xxx.t',
                    trace_line => 7,

                    # There can be more than one diagnostics message or todo
                    # reason, so these are always an array when present.
                    todo => ['broken'],

                    # Diag message was turned into a note since the assertion was
                    # TODO
                    note => ["Failed test 'fixme'\nat xxx.t line 7."],
                },
                {
                    causes_failure => 0,

                    plan => 3,

                    trace_file => 'xxx.t',
                    trace_line => 8,
                },
            ],
            "Flattened events look like we expect"
        );

    See [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) for a full description of what "flatten()" provides for
    each event.

## METHODS
    Please note that no methods modify the original instance unless asked to do so.

  CONSTRUCTION
    $events = [Test2::API::InterceptResult](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult/markdown)->new(@EVENTS)
    $events = [Test2::API::InterceptResult](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult/markdown)->new_from_ref(\@EVENTS)
        These create a new instance of [Test2::API::InterceptResult](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult/markdown) from the given events.

        In the first form a new blessed arrayref is returned. In the 'new_from_ref' form the
        reference you pass in is directly blessed.

        Both of these will throw an exception if called in void context. This is mainly important
        for the 'filtering' methods listed below which normally return a new instance, they throw an
        exception in such cases as it probably means someone meant to filter the original in place.

    $clone = $events->clone()
        Make a clone of the original events. Note that this is a deep copy, the entire structure is
        duplicated. This uses "dclone" from Storable to achieve the deep clone.

  NORMALIZATION
    @events = $events->event_list
        This returns all the events in list-form.

    $hub = $events->hub
        This returns a new [Test2::Hub](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AHub/markdown) instance that has processed all the events contained in the
        instance. This gives you a simple way to inspect the state changes your events cause.

    $state = $events->state
        This returns a summary of the state of a hub after processing all the events.

            {
                count        => 2,      # Number of assertions made
                failed       => 1,      # Number of test failures seen
                is_passing   => 0,      # Boolean, true if the test would be passing
                                        # after the events are processed.

                plan         => 2,      # Plan, either a number, undef, 'SKIP', or 'NO PLAN'
                follows_plan => 1,      # True if there is a plan and it was followed.
                                        # False if the plan and assertions did not
                                        # match, undef if no plan was present in the
                                        # event list.

                bailed_out   => undef,  # undef unless there was a bail-out in the
                                        # events in which case this will be a string
                                        # explaining why there was a bailout, if no
                                        # reason was given this will simply be set to
                                        # true (1).

                skip_reason  => undef,  # If there was a skip_all this will give the
                                        # reason.
            }

    $new = $events->upgrade
    $events->upgrade(in_place => $BOOL)
        Note: This normally returns a new instance, leaving the original unchanged. If you call it
        in void context it will throw an exception. If you want to modify the original you must pass
        in the "in_place => 1" option. You may call this in void context when you ask to modify it
        in place. The in-place form returns the instance that was modified so you can chain methods.

        This will create a clone of the list where all events have been converted into
        [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) instances. This is extremely helpful as
        [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) provide a much better interface for working with events.
        This allows you to avoid thinking about legacy event types.

        This also means your tests against the list are not fragile if the tool you are testing
        randomly changes what type of events it generates (IE Changing from [Test2::Event::Ok](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AEvent%3A%3AOk/markdown) to
        [Test2::Event::Pass](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AEvent%3A%3APass/markdown), both make assertions and both will normalize to identical (or close
        enough) [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) instances.

        Really you almost always want this, the only reason it is not done automatically is to make
        sure the "intercept()" tool is backwards compatible.

    $new = $events->squash_info
    $events->squash_info(in_place => $BOOL)
        Note: This normally returns a new instance, leaving the original unchanged. If you call it
        in void context it will throw an exception. If you want to modify the original you must pass
        in the "in_place => 1" option. You may call this in void context when you ask to modify it
        in place. The in-place form returns the instance that was modified so you can chain methods.

        Note: All events in the new or modified instance will be converted to
        [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) instances. There is no way to avoid this, the squash
        operation requires the upgraded event class.

        [Test::More](https://www.chedong.com/phpMan.php/perldoc/Test%3A%3AMore/markdown) and many other legacy tools would send notes, diags, and assertions as seperate
        events. A subtest in [Test::More](https://www.chedong.com/phpMan.php/perldoc/Test%3A%3AMore/markdown) would send a note with the subtest name, the subtest
        assertion, and finally a diagnostics event if the subtest failed. This method will normalize
        things by squashing the note and diag into the same event as the subtest (This is different
        from putting them into the subtest, which is not what happens).

  FILTERING
    Note: These normally return new instances, leaving the originals unchanged. If you call them in
    void context they will throw exceptions. If you want to modify the originals you must pass in
    the "in_place => 1" option. You may call these in void context when you ask to modify them in
    place. The in-place forms return the instance that was modified so you can chain methods.

   %PARAMS
    These all accept the same 2 optional parameters:

    in_place => $BOOL
        When true the method will modify the instance in place instead of returning a new instance.

    args => \@ARGS
        If you wish to pass parameters into the event method being used for filtering, you may do so
        here.

   METHODS
    $events->grep($CALL, %PARAMS)
        This is essentially:

            [Test2::API::InterceptResult](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult/markdown)->new(
                grep { $_->$CALL( @{$PARAMS{args}} ) } $self->event_list,
            );

        Note: that $CALL is called on an upgraded version of the event, though the events returned
        will be the original ones, not the upgraded ones.

        $CALL may be either the name of a method on [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown), or a
        coderef.

    $events->asserts(%PARAMS)
        This is essentially:

            $events->grep(has_assert => @{$PARAMS{args}})

        It returns a new instance containing only the events that made assertions.

    $events->subtests(%PARAMS)
        This is essentially:

            $events->grep(has_subtest => @{$PARAMS{args}})

        It returns a new instance containing only the events that have subtests.

    $events->diags(%PARAMS)
        This is essentially:

            $events->grep(has_diags => @{$PARAMS{args}})

        It returns a new instance containing only the events that have diags.

    $events->notes(%PARAMS)
        This is essentially:

            $events->grep(has_notes => @{$PARAMS{args}})

        It returns a new instance containing only the events that have notes.

    $events->errors(%PARAMS)
        Note: Errors are NOT failing assertions. Failing assertions are a different thing.

        This is essentially:

            $events->grep(has_errors => @{$PARAMS{args}})

        It returns a new instance containing only the events that have errors.

    $events->plans(%PARAMS)
        This is essentially:

            $events->grep(has_plan => @{$PARAMS{args}})

        It returns a new instance containing only the events that set the plan.

    $events->causes_fail(%PARAMS)
    $events->causes_failure(%PARAMS)
        These are essentially:

            $events->grep(causes_fail    => @{$PARAMS{args}})
            $events->grep(causes_failure => @{$PARAMS{args}})

        Note: "causes_fail()" and "causes_failure()" are both aliases for eachother in events, so
        these methods are effectively aliases here as well.

        It returns a new instance containing only the events that cause failure.

  MAPPING
    These methods ALWAYS return an arrayref.

    Note: No methods on [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) alter the event in any way.

    Important Notes about Events:

    [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) was tailor-made to be used in event-lists. Most methods that
    are not applicable to a given event will return an empty list, so you normally do not need to
    worry about unwanted "undef" values or exceptions being thrown. Mapping over event methods is an
    entended use, so it works well to produce lists.

    Exceptions to the rule:

    Some methods such as "causes_fail" always return a boolean true or false for all events. Any
    method prefixed with "the_" conveys the intent that the event should have exactly 1 of
    something, so those will throw an exception when that condition is not true.

    $arrayref = $events->map($CALL, %PARAMS)
        This is essentially:

            [ map { $_->$CALL(@{ $PARAMS{args} }) } $events->upgrade->event_list ];

        $CALL may be either the name of a method on [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown), or a
        coderef.

    $arrayref = $events->flatten(%PARAMS)
        This is essentially:

            [ map { $_->flatten(@{ $PARAMS{args} }) } $events->upgrade->event_list ];

        It returns a new list of flattened structures.

        See [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) for details on what "flatten()" returns.

    $arrayref = $events->briefs(%PARAMS)
        This is essentially:

            [ map { $_->briefs(@{ $PARAMS{args} }) } $events->upgrade->event_list ];

        It returns a new list of event briefs.

        See [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) for details on what "brief()" returns.

    $arrayref = $events->summaries(%PARAMS)
        This is essentially:

            [ map { $_->summaries(@{ $PARAMS{args} }) } $events->upgrade->event_list ];

        It returns a new list of event summaries.

        See [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) for details on what "summary()" returns.

    $arrayref = $events->subtest_results(%PARAMS)
        This is essentially:

            [ map { $_->subtest_result(@{ $PARAMS{args} }) } $events->upgrade->event_list ];

        It returns a new list of event summaries.

        See [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) for details on what "subtest_result()" returns.

    $arrayref = $events->diag_messages(%PARAMS)
        This is essentially:

            [ map { $_->diag_messages(@{ $PARAMS{args} }) } $events->upgrade->event_list ];

        It returns a new list of diagnostic messages (strings).

        See [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) for details on what "diag_messages()" returns.

    $arrayref = $events->note_messages(%PARAMS)
        This is essentially:

            [ map { $_->note_messages(@{ $PARAMS{args} }) } $events->upgrade->event_list ];

        It returns a new list of notification messages (strings).

        See [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) for details on what "note_messages()" returns.

    $arrayref = $events->error_messages(%PARAMS)
        This is essentially:

            [ map { $_->error_messages(@{ $PARAMS{args} }) } $events->upgrade->event_list ];

        It returns a new list of error messages (strings).

        See [Test2::API::InterceptResult::Event](https://www.chedong.com/phpMan.php/perldoc/Test2%3A%3AAPI%3A%3AInterceptResult%3A%3AEvent/markdown) for details on what "error_messages()" returns.

## SOURCE
    The source code repository for Test2 can be found at <http://github.com/Test-More/test-more/>.

## MAINTAINERS
    Chad Granum <<exodist@cpan.org>>

## AUTHORS
    Chad Granum <<exodist@cpan.org>>

## COPYRIGHT
    Copyright 2020 Chad Granum <<exodist@cpan.org>>.

    This program is free software; you can redistribute it and/or modify it under the same terms as
    Perl itself.

    See <http://dev.perl.org/licenses/>