Test::Roo(3) Composable, reusable tests with roles and Moo

VERSION

version 1.004

SYNOPSIS

Define test behaviors and required fixtures in a role:


# t/lib/ObjectCreation.pm
package ObjectCreation;
use Test::Roo::Role; # loads Moo::Role and Test::More
requires 'class'; # we need this fixture
test 'object creation' => sub {
my $self = shift;
require_ok( $self->class );
my $obj = new_ok( $self->class );
};
1;

Provide fixtures and run tests from the .t file: 

    # t/test.t
    use Test::Roo; # loads Moo and Test::More
    use lib 't/lib';
    # provide the fixture
    has class => (
        is      => 'ro',
        default => sub { "Digest::MD5" },
    );
    # specify behaviors to test
    with 'ObjectCreation';
    # give our subtests a pretty label
    sub _build_description { "Testing " . shift->class }
    # run the test with default fixture
    run_me;
    # run the test with different fixture
    run_me( { class => "Digest::SHA1" } );
    done_testing;

Result: 

    $ prove -lv t
    t/test.t ..
            ok 1 - require Digest::MD5;
            ok 2 - The object isa Digest::MD5
            1..2
        ok 1 - object creation
        1..1
    ok 1 - Testing Digest::MD5
            ok 1 - require Digest::SHA1;
            ok 2 - The object isa Digest::SHA1
            1..2
        ok 1 - object creation
        1..1
    ok 2 - Testing Digest::SHA1
    1..2
    ok
    All tests successful.
    Files=1, Tests=2,  0 wallclock secs ( 0.02 usr  0.01 sys +  0.06 cusr  0.00 csys =  0.09 CPU)
    Result: PASS

DESCRIPTION

This module allows you to compose Test::More tests from roles. It is inspired by the excellent Test::Routine module, but uses Moo instead of Moose. This gives most of the benefits without the need for Moose as a test dependency.

Test files are Moo classes. You can define any needed test fixtures as Moo attributes. You define tests as method modifiers --- similar in concept to "subtest" in Test::More, but your test method will be passed the test object for access to fixture attributes. You may compose any Moo::Role into your test to define attributes, require particular methods, or define tests.

This means that you can isolate test behaviors into roles which require certain test fixtures in order to run. Your main test file will provide the fixtures and compose the roles to run. This makes it easy to reuse test behaviors.

For example, if you are creating tests for Awesome::Module, you could create the test behaviors as Awesome::Module::Test::Role and distribute it with your module. If another distribution subclasses Awesome::Module, it can compose the Awesome::Module::Test::Role behavior for its own tests.

No more copying and pasting tests from a super class! Superclasses define and share their tests. Subclasses provide their own fixtures and run the tests.

USAGE

Importing Test::Roo also loads Moo (which gives you strictures with fatal warnings and other goodies) and makes the current package a subclass of Test::Roo::Class.

Importing also loads Test::More. No test plan is used. The "done_testing" function must be used at the end of every test file. Any import arguments are passed through to Test::More's "import" method.

See also Test::Roo::Role for test role usage.

Creating fixtures

You can create fixtures with normal Moo syntax. You can even make them lazy if you want: 

    has fixture => (
        is => 'lazy'
    );
    sub _build_fixture { ... }

This becomes really useful with Test::Roo::Role. A role could define the attribute and require the builder method to be provided by the main test class.

Composing test roles

You can use roles to define units of test behavior and then compose them into your test class using the "with" function. Test roles may define attributes, declare tests, require certain methods and anything else you can regularly do with roles. 

    use Test::Roo;
    with 'MyTestRole1', 'MyTestRole2';

See Test::Roo::Role and the Test::Roo::Cookbook for details and examples.

Setup and teardown

You can add method modifiers around the "setup" and "teardown" methods and these will be run before tests begin and after tests finish (respectively). 

    before  setup     => sub { ... };
    after   teardown  => sub { ... };

You can also add method modifiers around "each_test", which will be run before and after every individual test. You could use these to prepare or reset a fixture. 

    has fixture => ( is => 'lazy, clearer => 1, predicate => 1 );
    after  each_test => sub { shift->clear_fixture };

Roles may also modify "setup", "teardown", and "each_test", so the order that modifiers will be called will depend on when roles are composed. Be careful with "each_test", though, because the global effect may make composition more fragile.

You can call test functions in modifiers. For example, you could confirm that something has been set up or cleaned up. 

    before each_test => sub { ok( ! shift->has_fixture ) };

Running tests

The simplest way to use Test::Roo with a single .t file is to let the "main" package be the test class and call "run_me" in it: 

    # t/test.t
    use Test::Roo; # loads Moo and Test::More
    has class => (
        is      => 'ro',
        default => sub { "Digest::MD5" },
    );
    test 'load class' => sub {
        my $self = shift;
        require_ok( $self->class );
    }
    run_me;
    done_testing;

Calling "run_me(@args)" is equivalent to calling "__PACKAGE__->run_tests(@args)" and runs tests for the current package.

You may specify an optional description or hash reference of constructor arguments to customize the test object: 

    run_me( "load MD5" );
    run_me( { class => "Digest::MD5" } );
    run_me( "load MD5", { class => "Digest::MD5" } );

See Test::Roo::Class for more about the "run_tests" method.

Alternatively, you can create a separate package (in the test file or in a separate .pm file) and run tests explicitly on that class. 

    # t/test.t
    package MyTest;
    use Test::Roo;
    use lib 't/lib';
    has class => (
        is       => 'ro',
        required => 1,
    );
    with 'MyTestRole';
    package main;
    use strictures;
    use Test::More;
    for my $c ( qw/Digest::MD5 Digest::SHA/ ) {
        MyTest->run_tests("Testing $c", { class => $c } );
    }
    done_testing;

EXPORTED FUNCTIONS

Loading Test::Roo exports subroutines into the calling package to declare and run tests.

test

    test $label => sub { ... };

The "test" function adds a subtest. The code reference will be called with the test object as its only argument.

Tests are run in the order declared, so the order of tests from roles will depend on when they are composed relative to other test declarations.

top_test

    top_test $label => sub { ... };

The "top_test" function adds a ``top level'' test. Works exactly like ``test'' except it will not start a subtest. This is especially useful in very simple testing situations where the extra subtest level is just noise.

So for example the following test 

    # t/test.t
    use Test::Roo;
    has class => (
        is       => 'ro',
        required => 1,
    );
    top_test basic => sub {
        my $self = shift;
        require_ok($self->class);
        isa_ok($self->class->new, $self->class);
    };
    for my $c ( qw/Digest::MD5 Digest::SHA/ ) {
        run_me("Testing $c", { class => $c } );
    }
    done_testing;

produces the following TAP 

    t/test.t ..
        ok 1 - require Digest::MD5;
        ok 2 - The object isa Digest::MD5
        1..2
    ok 1 - Testing Digest::MD5
        ok 1 - require Digest::SHA1;
        ok 2 - The object isa Digest::SHA1
        1..2
    ok 2 - Testing Digest::SHA1
    1..2
    ok
    All tests successful.
    Files=1, Tests=2,  0 wallclock secs ( 0.02 usr  0.01 sys +  0.06 cusr  0.00 csys =  0.09 CPU)
    Result: PASS

run_me

    run_me;
    run_me( $description );
    run_me( $init_args   );
    run_me( $description, $init_args );

The "run_me" function calls the "run_tests" method on the current package and passes all arguments to that method. It takes a description and/or a hash reference of constructor arguments.

DIFFERENCES FROM TEST::ROUTINE

While this module was inspired by Test::Routine, it is not a drop-in replacement. Here is an overview of major differences:
  • Test::Roo uses Moo; Test::Routine uses Moose
  • Loading Test::Roo makes the importing package a class; in Test::Routine it becomes a role
  • Loading Test::Roo loads Test::More; Test::Routine does not
  • In Test::Roo, "run_test" is a method; in Test::Routine it is a function and takes arguments in a different order
  • In Test::Roo, all role composition must be explicit using "with"; in Test::Routine, the "run_tests" command can also compose roles
  • In Test::Roo, test blocks become method modifiers hooked on an empty method; in Test::Routine, they become methods run via introspection
  • In Test::Roo, setup and teardown are done by modifying "setup" and "teardown" methods; in Test::Routine they are done by modifying "run_test"

SUPPORT

Bugs / Feature Requests

Please report any bugs or feature requests through the issue tracker at <https://github.com/dagolden/Test-Roo/issues>. You will be notified automatically of any progress on your issue.

Source Code

This is open source software. The code repository is available for public review and contribution under the terms of the license.

<https://github.com/dagolden/Test-Roo> 

  git clone https://github.com/dagolden/Test-Roo.git

AUTHOR

David Golden <[email protected]>

CONTRIBUTORS

COPYRIGHT AND LICENSE

This software is Copyright (c) 2013 by David Golden.

This is free software, licensed under: 

  The Apache License, Version 2.0, January 2004

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