NAME

Test::ExpectAndCheck - expect/check-style unit testing with object methods

SYNOPSIS

   use Test::More;
   use Test::ExpectAndCheck;

   my ( $controller, $puppet ) = Test::ExpectAndCheck->create;

   {
      $controller->expect( act => 123, 45 )
         ->returns( 678 );

      is( $puppet->act( 123, 45 ), 678, '$puppet->act returns result' );

      $controller->check_and_clear( '->act' );
   }

   done_testing;

DESCRIPTION

This package creates objects that assist in writing unit tests with mocked object instances. Each mocked "puppet" instance will expect to receive a given list of method calls. Each method call is checked that it received the right arguments, and will return a prescribed result. At the end of each test, each object is checked to ensure all the expected methods were called.

METHODS

create

   ( $controller, $puppet ) = Test::ExpectAndCheck->create;

Objects are created in "entangled pairs" by the create method. The first object is called the "controller", and is used by the unit testing script to set up what method calls are to be expected, and what their results shall be. The second object is the "puppet", the object to be passed to the code being tested, on which the expected method calls are (hopefully) invoked. It will have whatever interface is implied by the method call expectations.

expect

   $exp = $controller->expect( $method, @args )

Specifies that the puppet will expect to receive a method call of the given name, with the given arguments.

The argument values are compared using "cmp_deeply" in Test::Deep. Values can be specified literally, or using any of the "Special Comparisons" defined by Test::Deep.

The test script can call the "returns" or "throws" methods on the expectation to set what the result of invoking this method will be.

check_and_clear

   $controller->check_and_clear( $name );

Checks that by now, every expected method has been called, and emits a new test output line via Test::Builder. Regardless, the expectations are also cleared out ready for the start of the next test.

EXPECTATIONS

Each value returned by the "expect" method is an "expectation", an object that represents one expected method call, the arguments it should receive, and the return value it should provide.

returns

   $exp->returns( @result )

Sets the result that will be returned by this method call.

throws

   $exp->throws( $e )

Sets the exception that will be thrown by this method call.

AUTHOR

Paul Evans <leonerd@leonerd.org.uk>