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A GUIDE TO WRITING TESTS FOR MODULE::BUILD

This document provides tips on writing new tests for Module::Build. Please note that many existing tests were written prior to these guidelines and have many different styles. Please don't copy/paste old tests by rote without considering better ways to test. See sample.t for a starter test file.

TEST FILE PREAMBLE

Every Module::Build test should begin with the same preamble to ensure that the test library is set properly and that the correct version of Module::Build is being tested.

  use strict;
  use lib 't/lib';
  use MBTest tests => 2; # or 'no_plan'

  blib_load('Module::Build');

The MBTest module is in t/lib/ and subclasses Test::More. When loaded it cleans up several environment variables that could cause problems, tweaks @INC and exports several helper functions. See that module for details.

CREATING A TEST DISTRIBUTION

The DistGen module in t/lib/ should be used to create sample distributions for testing. It provides numerous helpful methods to create a skeleton distribution, add files, change files, and so on. Run perldoc on t/lib/DistGen.pm to see the documentation.

  # CREATE A TEST DISTRIBUTION

  use DistGen;

  # create dist object in a temp directory
  my $dist = DistGen->new;

  # enter the test distribution directory before further testing
  $dist->chdir_in;

  # generate the skeleton files
  $dist->regen;

GETTING A MODULE::BUILD OBJECT

From inside the test distribution, you can get the Module::Build object configured in Build.PL using the new_from_context method on the dist object. This is just like Module::Build's new_from_context except it passes quiet => 1 to avoid sending output to the terminal. Use the Module::Build object to test the programmatic API.

  my $mb = $dist->new_from_context( quiet => 1 );
  isa_ok( $mb, "Module::Build" );
  is( $mb->dist_name, "Simple", "dist_name is 'Simple'" );

TESTING THE COMMAND LINE API

The command line API is tested by running subprocesses, not via a Module::Build object. The DistGen object has helper methods for running Build.PL and Build and passing arguments on the command line.

  $dist->run_build_pl( '--quiet' );
  $dist->run_build( 'test' );

TYPICAL TESTING CYCLE

The typical testing cycle is to generate or modify a test distribution, either through the DistGen object or directly in the filesystem, then regenerate the distribution and test it (or run command line tests and observe the result.)

  # Modify the distribution

  $dist->change_build_pl(
    {
      module_name   => $dist->name,
      license       => 'artistic',
    }
  );
  $dist->regen;

  # Get a new build object and test it

  $mb = $dist->new_from_context;
  is( $mb->license, "artistic", "saw 'artistic' license" );

COPYRIGHT

This documentation is Copyright (C) 2009 by David Golden. You can redistribute it and/or modify it under the same terms as Perl 5.10.0.