Test2::Mock(3perl)     Perl Programmers Reference Guide     Test2::Mock(3perl)


NAME
       Test2::Mock - Module for managing mocked classes and instances.

DESCRIPTION
       This module lets you add and override methods for any package
       temporarily. When the instance is destroyed it will restore the package
       to its original state.

SYNOPSIS
           use Test2::Mock;
           use MyClass;

           my $mock = Test2::Mock->new(
               track => $BOOL, # enable call tracking if desired
               class => 'MyClass',
               override => [
                   name => sub { 'fred' },
                   ...
               ],
               add => [
                   is_mocked => sub { 1 }
                   ...
               ],
               ...
           );

           # Unmock the 'name' sub
           $mock->restore('name');

           ...

           $mock = undef; # Will remove all the mocking

CONSTRUCTION
METHODS
       $mock = Test2::Mock->new(class => $CLASS, ...)
           This will create a new instance of Test2::Mock that manages mocking
           for the specified $CLASS.

           Any "Test2::Mock" method can be used as a constructor argument,
           each should be followed by an arrayref of arguments to be used
           within the method. For instance the add() method:

               my $mock = Test2::Mock->new(
                   class => 'AClass',
                   add => [foo => sub { 'foo' }],
               );

           is identical to this:

               my $mock = Test2::Mock->new(
                   class => 'AClass',
               );
               $mock->add(foo => sub { 'foo' });

       $mock->track($bool)
           Turn tracking on or off. Any sub added/overridden/set when tracking
           is on will log every call in a hash retrievable via
           "$mock->tracking". Changing the tracking toggle will not affect
           subs already altered, but will affect any additional alterations.

       $hashref = $mock->sub_tracking
           The tracking data looks like this:

               {
                   sub_name => [
                       {sub_name => $sub_name, sub_ref => $mock_subref, args => [... copy of @_ from the call ... ]},
                       ...,
                       ...,
                   ],
               }

           Unlike call_tracking, this lists all calls by sub, so you can
           choose to only look at the sub specific calls.

           Please note: The hashref items with the subname and args are shared
           with call_tracking, modifying one modifies the other, so copy
           first!

       $arrayref = $mock->call_tracking
           The tracking data looks like this:

               [
                   {sub_name => $sub_name, sub_ref => $mock_subref, args => [... copy of @_ from the call ... ]},
                   ...,
                   ...,
               ]

           Unlike sub_tracking this lists all calls to any mocked sub, in the
           order they were called. To filter by sub use sub_tracking.

           Please note: The hashref items with the subname and args are shared
           with sub_tracking, modifying one modifies the other, so copy first!

       $mock->clear_sub_tracking()
       $mock->clear_sub_tracking(\@subnames)
           Clear tracking data. With no arguments ALL tracking data is
           cleared. When arguments are provided then only those specific keys
           will be cleared.

       $mock->clear_call_tracking()
           Clear all items from call_tracking.

       $mock->add('symbol' => ..., 'symbol2' => ...)
       $mock->override('symbol1' => ..., 'symbol2' => ...)
       $mock->set('symbol1' => ..., 'symbol2' => ...)
           add() and override() are the primary ways to add/modify methods for
           a class. Both accept the exact same type of arguments. The
           difference is that "override" will fail unless the symbol you are
           overriding already exists, "add" on the other hand will fail if the
           symbol does already exist.

           set() was more recently added for cases where you may not know if
           the sub already exists. These cases are rare, and set should be
           avoided (think of it like 'no strict'). However there are valid use
           cases, so it was added.

           Note: Think of override as a push operation. If you call override
           on the same symbol multiple times it will track that. You can use
           restore() as a pop operation to go back to the previous mock.
           "reset" can be used to remove all the mocking for a symbol.

           Arguments must be a symbol name, with optional sigil, followed by a
           new specification of the symbol. If no sigil is specified then '&'
           (sub) is assumed. A simple example of overriding a sub:

               $mock->override(foo => sub { 'overridden foo' });
               my $val = $class->foo; # Runs our override
               # $val is now set to 'overridden foo'

           You can also simply provide a value and it will be wrapped in a sub
           for you:

               $mock->override( foo => 'foo' );

           The example above will generate a sub that always returns the
           string 'foo'.

           There are three *special* values that can be used to generate
           accessors:

               $mock->add(
                   name => 'rw',   # Generates a read/write accessor
                   age  => 'ro',   # Generates a read only accessor
                   size => 'wo',   # Generates a write only accessor
               );

           If you want to have a sub that actually returns one of the three
           special strings, or that returns a coderef, you can use a hashref
           as the spec:

               my $ref = sub { 'my sub' };
               $mock->add(
                   rw_string => { val => 'rw' },
                   ro_string => { val => 'ro' },
                   wo_string => { val => 'wo' },
                   coderef   => { val => $ref }, # the coderef method returns $ref each time
               );

           You can also override/add other symbol types, such as hash:

               package Foo;
               ...

               $mock->add('%foo' => {a => 1});

               print $Foo::foo{a}; # prints '1'

           You can also tell mock to deduce the symbol type for the
           add/override from the reference, rules are similar to glob
           assignments:

               $mock->add(
                   -foo => sub { 'foo' },     # Adds the &foo sub to the package
                   -foo => { foo => 1 },      # Adds the %foo hash to the package
                   -foo => [ 'f', 'o', 'o' ], # Adds the @foo array to the package
                   -foo => \"foo",            # Adds the $foo scalar to the package
               );

       $mock->restore($SYMBOL)
           Restore the symbol to what it was before the last override. If the
           symbol was recently added this will remove it. If the symbol has
           been overridden multiple times this will ONLY restore it to the
           previous state. Think of "override" as a push operation, and
           "restore" as the pop operation.

       $mock->reset($SYMBOL)
           Remove all mocking of the symbol and restore the original symbol.
           If the symbol was initially added then it will be completely
           removed.

       $mock->orig($SYMBOL)
           This will return the original symbol, before any mocking. For
           symbols that were added this will return undef.

       $mock->current($SYMBOL)
           This will return the current symbol.

       $mock->reset_all
           Remove all added symbols, and restore all overridden symbols to
           their originals.

       $mock->add_constructor($NAME => $TYPE)
       $mock->override_constructor($NAME => $TYPE)
           This can be used to inject constructors. The first argument should
           be the name of the constructor. The second argument specifies the
           constructor type.

           The "hash" type is the most common, all arguments are used to
           create a new hash that is blessed.

               hash => sub  {
                   my ($class, %params) = @_;
                   return bless \%params, $class;
               };

           The "array" type is similar to the hash type, but accepts a list
           instead of key/value pairs:

               array => sub {
                   my ($class, @params) = @_;
                   return bless \@params, $class;
               };

           The "ref" type takes a reference and blesses it. This will modify
           your original input argument.

               ref => sub {
                   my ($class, $params) = @_;
                   return bless $params, $class;
               };

           The "ref_copy" type will copy your reference and bless the copy:

               ref_copy => sub {
                   my ($class, $params) = @_;
                   my $type = reftype($params);

                   return bless {%$params}, $class
                       if $type eq 'HASH';

                   return bless [@$params], $class
                       if $type eq 'ARRAY';

                   croak "Not sure how to construct a '$class' from '$params'";
               };

       $mock->before($NAME, sub { ... })
           This will replace the original sub $NAME with a new sub that calls
           your custom code just before calling the original method. The
           return from your custom sub is ignored. Your sub and the original
           both get the unmodified arguments.

       $mock->after($NAME, sub { ... })
           This is similar to before, except your callback runs after the
           original code.  The return from your callback is ignored.

       $mock->around($NAME, sub { ... })
           This gives you the chance to wrap the original sub:

               $mock->around(foo => sub {
                   my $orig = shift;
                   my $self = shift;
                   my (@args) = @_;

                   ...
                   $self->$orig(@args);
                   ...

                   return ...;
               });

           The original sub is passed in as the first argument, even before
           $self. You are responsible for making sure your wrapper sub returns
           the correct thing.

       $mock->autoload
           This will inject an "AUTOLOAD" sub into the class. This autoload
           will automatically generate read-write accessors for any sub called
           that does not already exist.

       $mock->block_load
           This will prevent the real class from loading until the mock is
           destroyed. This will fail if the class is already loaded. This will
           let you mock a class completely without loading the original
           module.

       $pm_file = $mock->file
           This returns the relative path to the file for the module. This
           corresponds to the %INC entry.

       $bool = $mock->purge_on_destroy($bool)
           When true, this will cause the package stash to be completely
           obliterated when the mock object falls out of scope or is otherwise
           destroyed. You do not normally want this.

       $stash = $mock->stash
           This returns the stash for the class being mocked. This is the
           equivalent of:

               my $stash = \%{"${class}\::"};

           This saves you from needing to turn off strict.

       $class = $mock->class
           The class being mocked by this instance.

       $p = $mock->parent
           If you mock a class twice the first instance is the parent, the
           second is the child. This prevents the parent from being destroyed
           before the child, which would lead to a very unpleasant situation.

       $c = $mock->child
           Returns the child mock, if any.

SOURCE
       The source code repository for Test2-Suite can be found at
       <https://github.com/Test-More/Test2-Suite/>.

MAINTAINERS
       Chad Granum <exodist@cpan.org>

AUTHORS
       Chad Granum <exodist@cpan.org>

COPYRIGHT
       Copyright 2018 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 <https://dev.perl.org/licenses/>

perl v5.40.0                      2024-09-01                Test2::Mock(3perl)