1Test::Routine::Manual::UDseemro(C3o)ntributed Perl DocumTeenstta:t:iRoonutine::Manual::Demo(3)
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6 Test::Routine::Manual::Demo - a walkthrough, in code, of Test::Routine
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9 version 0.028
10
12 This module has the same support period as perl itself: it supports
13 the two most recent versions of perl. (That is, if the most recently
14 released version is v5.40, then this module should work on both v5.40
15 and v5.38.)
16 Although it may work on older versions of perl, no guarantee is made
18 that the minimum required version will not be increased. The version
19 may be increased for any reason, and there is no promise that patches
20 will be accepted to lower the minimum required perl.
21
23 t/demo/01-demo.t
24 #!/bin/env perl
25 use strict;
26 use warnings;
27 # This test is both a test and an example of how Test::Routine works! Welcome
29 # to t/01-demo.t, I will be your guide, rjbs.
30 {
32 # This block defines the HashTester package. It's a Test::Routine, meaning
33 # it's a role. We define state that the test will need to keep and any
34 # requirements we might have.
35 #
36 # Before we can run this test, we'll need to compose the role into a class so
37 # that we can make an instance.
38 package HashTester;
39 use Test::Routine;
40 # We import stuff from Test::More because, well, who wants to re-write all
42 # those really useful test routines that exist out there? Maybe somebody,
43 # but not me.
44 use Test::More;
45 # ...but then we use namespace::autoclean to get rid of the routines once
47 # we've bound to them. This is just standard Moose practice, anyway, right?
48 use namespace::autoclean;
49 # Finally, some state! Every test will get called as method on an instance,
51 # and it will have this attribute. Here are some points of interest:
52 #
53 # - We're giving this attribute a builder, so it will try to get built with a
54 # call to $self->build_hash_to_test -- so each class that composes this
55 # role can provide means for these attributes (fixtures) to be generated as
56 # needed.
57 #
58 # - We are not adding "requires 'build_hash_to_test'", because then we can
59 # apply this role to Moose::Object and instantiate it with a given value
60 # in the constructor. There will be an example of this below. This lets
61 # us re-use these tests in many variations without having to write class
62 # after class.
63 #
64 # - We don't use lazy_build because it would create a clearer. If someone
65 # then cleared our lazy_build fixture, it could not be re-built in the
66 # event that we'd gotten it explicitly from the constructor!
67 #
68 # Using Moose attributes for our state and fixtures allows us to get all of
69 # their powerful behaviors like types, delegation, traits, and so on, and
70 # allows us to decompose shared behavior into roles.
71 #
72 has hash_to_test => (
73 is => 'ro',
74 isa => 'HashRef',
75 builder => 'build_hash_to_test',
76 );
77 # Here, we're just declaring an actual test that we will run. This sub will
79 # get installed as a method with a name that won't get clobbered easily. The
80 # method will be found later by run_tests so we can find and execute all
81 # tests on an instance.
82 #
83 # There is nothing magical about this method! Calling this method is
84 # performed in a Test::More subtest block. A TAP plan can be issued with
85 # "plan", and we can issue TODO or SKIP directives the same way. There is
86 # none of the return-to-skip magic that we find in Test::Class.
87 #
88 # The string after "test" is used as the method name -- which means we're
89 # getting a method name with spaces in it. This can be slightly problematic
90 # if you try to use, say, ::, in a method name. For the most part, it works
91 # quite well -- but look at the next test for an example of how to give an
92 # explicit description.
93 test "only one key in hash" => sub {
94 my ($self) = @_;
95 my $hash = $self->hash_to_test;
97 is(keys %$hash, 1, "we have one key in our test hash");
99 is(2+2, 4, "universe still okay");
100 };
101 # The only thing of note here is that we're passing a hashref of extra args
103 # to the test method constructor. "desc" lets us set the test's description,
104 # which is used in the test output, so we can avoid weird method names being
105 # installed. Also note that we order tests more or less by order of
106 # definition, not by name or description.
107 test second_test => { desc => "Test::Routine demo!" } => sub {
108 pass("We're running this test second");
109 pass("...notice that the subtest's label is the 'desc' above");
110 pass("...and not the method name!");
111 };
112 }
113 {
115 # This package is one fixture against which we can run the HashTester
116 # routine. It has the only thing it needs: a build_hash_to_test method.
117 # Obviously real examples would have more to them than this.
118 package ProcessHash;
119 use Moose;
120 with 'HashTester';
121 use namespace::autoclean;
123 sub build_hash_to_test { return { $$ => $^T } }
125 }
126 # Now we're into the body of the test program: where tests actually get run.
128 # We use Test::Routine::Util to get its "run_tests" routine, which runs the
130 # tests on an instance, building it if needed.
131 use Test::Routine::Util;
132 # We use Test::More to get done_testing. We don't assume that run_tests is the
134 # entire test, because that way we can (as we do here) run multiple test
135 # instances, and can intersperse other kinds of sanity checks amongst the
136 # Test::Routine-style tests.
137 use Test::More;
138 is(2+2, 4, "universe still makes sense") or BAIL_OUT("PANIC!");
140 # The first arg is a description for the subtest that will be run. The second,
142 # here, is a class that will be instantiated and tested.
143 run_tests('ProcessHash class' => 'ProcessHash');
144 # Here, the second argument is an instance of a class to test.
146 run_tests('ProcessHash obj' => ProcessHash->new({ hash_to_test => { 1 => 0 }}));
147 # We could also just supply a class name and a set of args to pass to new.
149 # The below is very nearly equivalent to the above:
150 run_tests('ProcessHash new' => ProcessHash => { hash_to_test => { 1 => 0 }});
151 # ...and here, the second arg is not a class or instance at all, but the
153 # Test::Routine role (by name). Since we know we can't instantiate a role,
154 # run_tests will try to compose it with Moose::Object. Then the args are used
155 # as the args to ->new on the new class, as above. This lets us write
156 # Test::Routines that can be tested with the right state to start with, or
157 # Test::Routines that need to be composed with testing fixture classes.
158 run_tests(
159 'HashTester with given state',
160 HashTester => {
161 hash_to_test => { a => 1 },
162 },
163 );
164 # There's one more interesting way to run out tests, but it's demonstrated in
166 # 02-simple.t instead of here. Go check that out.
167 # ...and we're done!
169 done_testing;
170 t/demo/02-simple.t
172 # Welcome to part two of the Test::Routine demo. This is showing how you can
173 # write quick one-off tests without having to write a bunch of .pm files or
174 # (worse?) embed packages in bare blocks in the odious way that 01-demo.t did.
175 #
176 # First off, we use Test::Routine. As it did before, this turns the current
177 # package (main!) into a Test::Routine role. It also has the pleasant
178 # side-effect of turning on strict and warnings.
179 use Test::Routine;
180 # Then we bring in the utils, because we'll want to run_tests later.
182 use Test::Routine::Util;
183 # And, finally, we bring in Test::More so that we can use test assertions, and
185 # namespace::autoclean to clean up after us.
186 use Test::More;
187 use namespace::autoclean;
188 # We're going to give our tests some state. It's nothing special.
190 has counter => (
191 is => 'rw',
192 isa => 'Int',
193 default => 0,
194 );
195 # Then another boring but useful hunk of code: a method for our test routine.
197 sub counter_is_even {
198 my ($self) = @_;
199 return $self->counter % 2 == 0;
200 }
201 # Then we can write some tests, just like we did before. Here, we're writing
203 # several tests, and they will be run in the order in which they were defined.
204 # You can see that they rely on the state being maintained.
205 test 'start even' => sub {
206 my ($self) = @_;
207 ok($self->counter_is_even, "we start with an even counter");
208 $self->counter( $self->counter + 1);
210 };
211 test 'terminate odd' => sub {
213 my ($self) = @_;
214 ok(! $self->counter_is_even, "the counter is odd, so state was preserved");
216 pass("for your information, the counter is " . $self->counter);
217 };
218 # Now we can run these tests just by saying "run_me" -- rather than expecting a
220 # class or role name, it uses the caller. In this case, the calling package
221 # (main!) is a Test::Routine, so the runner composes it with Moose::Object,
222 # instantiating it, and running the tests on the instance.
223 run_me;
224 # Since each test run gets its own instance, we can run the test suite again,
226 # possibly to verify that the test suite is not destructive of some external
227 # state.
228 run_me("second run");
229 # And we can pass in args to use when constructing the object to be tested.
231 # Given the tests above, we can pick any starting value for "counter" that is
232 # even.
233 run_me({ counter => 192 });
234 # ...and we're done!
236 done_testing;
237 # More Test::Routine behavior is demonstrated in t/03-advice.t and t/04-misc.t
239 # Go have a look at those!
240 t/demo/03-advice.t
242 use Test::Routine;
243 use Test::Routine::Util;
244 use Test::More;
245 use namespace::autoclean;
247 # xUnit style testing has the idea of setup and teardown that happens around
249 # each test. With Test::Routine, we assume that you will do most of this sort
250 # of thing in your BUILD, DEMOLISH, and attribute management. Still, you can
251 # easily do setup and teardown by applying method modifiers to the "run_test"
252 # method, which your Test::Routine uses to run each test. Here's a simple
253 # example.
254 # We have the same boring state that we saw before. It's just an integer that
256 # is carried over between tests.
257 has counter => (
258 is => 'rw',
259 isa => 'Int',
260 lazy => 1,
261 default => 0,
262 clearer => 'clear_counter',
263 );
264 # The first test changes the counter's value and leaves it changed.
266 test test_0 => sub {
267 my ($self) = @_;
268 is($self->counter, 0, 'start with counter = 0');
270 $self->counter( $self->counter + 1);
271 is($self->counter, 1, 'end with counter = 1');
272 };
273 # The second test assumes that the value is the default, again. We want to
275 # make sure that before each test, the counter is reset, but we don't want to
276 # tear down and recreate the whole object, because it may have other, more
277 # expensive resources built.
278 test test_1 => sub {
279 my ($self) = @_;
280 is($self->counter, 0, 'counter is reset between tests');
282 };
283 # ...so we apply a "before" modifier to each test run, calling the clearer on
285 # the counter. When next accessed, it will re-initialize to zero. We could
286 # call any other code we want here, and we can compose numerous modifiers
287 # together onto run_test.
288 #
289 # If you want to clear *all* the object state between each test... you probably
290 # want to refactor.
291 before run_test => sub { $_[0]->clear_counter };
292 run_me;
294 done_testing;
295 t/demo/04-misc.t
297 use Test::Routine;
298 use Test::Routine::Util;
299 use Test::More;
300 use namespace::autoclean;
302 # One thing that the previous examples didn't show was how to mark tests as
304 # "skipped" or "todo." Test::Routine makes -no- provisions for these
305 # directives. Instead, it assumes you will use the entirely usable mechanisms
306 # provided by Test::More.
307 # This is a normal test. It is neither skipped nor todo.
309 test boring_ordinary_tests => sub {
310 pass("This is a plain old boring test that always passes.");
311 pass("It's here just to remind you what they look like.");
312 };
313 # To skip a test, we just add a "skip_all" plan. Because test methods get run
315 # in subtests, this skips the whole subtest, but nothing else.
316 test sample_skip_test => sub {
317 plan skip_all => "these tests don't pass, for some reason";
318 is(6, 9, "I don't mind.");
320 };
321 # To mark a test todo, we just set our local $TODO variable. Because the test
323 # is its own block, this works just like it would in any other Test::More test.
324 test sample_todo_test => sub {
325 local $TODO = 'demo of todo';
326 is(2 + 2, 5, "we can bend the fabric of reality");
328 };
329 run_me;
331 done_testing;
332 t/demo/05-multiple.t
334 #!/bin/env perl
335 use strict;
336 use warnings;
337 use Test::Routine::Util;
339 use Test::More;
340 # One of the benefits of building our sets of tests into roles instead of
342 # classes is that we can re-use them in whatever combination we want. We can
343 # break down sets of tests into bits that can be re-used in different cases.
344 # With classes, this would lead to multiple inheritance or other monstrosities.
345 # Here's a first Test::Routine. We use it to make sure that one of our
347 # fixture's attributes is a numeric id.
348 {
349 package Test::ThingHasID;
350 use Test::Routine;
351 use Test::More;
352 requires 'id';
354 test thing_has_numeric_id => sub {
356 my ($self) = @_;
357 my $id = $self->id;
359 like($id, qr/\A[0-9]+\z/, "the thing's id is a string of ascii digits");
360 };
361 }
362 # A second one ensures that the thing has an associated directory that
364 # looks like a unix path.
365 {
366 package Test::HasDirectory;
367 use Test::Routine;
368 use Test::More;
369 requires 'dir';
371 test thing_has_unix_dir => sub {
373 my ($self) = @_;
374 my $dir = $self->dir;
376 like($dir, qr{\A(?:/\w+)+/?\z}, "thing has a unix-like directory");
377 };
378 }
379 # We might have one class that is only expected to pass one test:
381 {
382 package JustHasID;
383 use Moose;
384 has id => (
386 is => 'ro',
387 default => sub {
388 my ($self) = @_;
389 return Scalar::Util::refaddr($self);
390 },
391 );
392 }
393 # ...and another class that should pass both:
395 {
396 package UnixUser;
397 use Moose;
398 has id => (is => 'ro', default => 501);
400 has dir => (is => 'ro', default => '/home/users/rjbs');
401 }
402 # So far, none of this is new, it's just a slightly different way of factoring
404 # things we've seen before. In t/01-demo.t, we wrote distinct test roles and
405 # classes, and we made our class compose the role explicitly. This can be
406 # a useful way to put these pieces together, but we also might want to write
407 # all these classes and roles as unconnected components and compose them only
408 # when we're ready to run our tests. When we do that, we can tell run_tests
409 # what to put together.
410 #
411 # Here, we tell it that we can test JustHasID with Test::ThingHasID:
412 run_tests(
413 "our JustHasID objects have ids",
414 [ 'JustHasID', 'Test::ThingHasID' ],
415 );
416 # ...but we can run two test routines against our UnixUser class
418 run_tests(
419 "unix users have dirs and ids",
420 [ 'UnixUser', 'Test::ThingHasID', 'Test::HasDirectory' ],
421 );
422 # We can still use the "attributes to initialize an object," and when doing
425 # that it may be that we don't care to run all the otherwise applicable tests,
426 # because they're not interesting in the scenario we're creating. For
427 # example...
428 run_tests(
429 "a trailing slash is okay in a directory",
430 [ 'UnixUser', 'Test::HasDirectory' ],
431 { dir => '/home/meebo/' },
432 );
433 # ...and we're done!
435 done_testing;
436
438 Ricardo Signes <rjbs@semiotic.systems>
439
441 This software is copyright (c) 2010 by Ricardo Signes.
442 This is free software; you can redistribute it and/or modify it under
444 the same terms as the Perl 5 programming language system itself.
445perl v5.34.0 2021-07-23 Test::Routine::Manual::Demo(3)