Convert tests to using subtests

[kraih]

Not a particularly hard task, but converting all tests is a lot of work. We want to go from:

# Promisify
is ref Mojo::Promise->resolve('foo'), 'Mojo::Promise', 'right class';
$promise = Mojo::Promise->reject('foo');
is ref $promise, 'Mojo::Promise', 'right class';
@errors = ();
$promise->catch(sub { push @errors, @_ })->wait;
is_deeply \@errors, ['foo'], 'promise rejected';
$promise = Mojo::Promise->resolve('foo');
is refaddr(Mojo::Promise->resolve($promise)), refaddr($promise), 'same object';
$promise = Mojo::Promise->resolve('foo');
isnt refaddr(Mojo::Promise->new->resolve($promise)), refaddr($promise),
  'different object';
$promise = Mojo::Promise->reject('foo');
is refaddr(Mojo::Promise->resolve($promise)), refaddr($promise), 'same object';
@errors = ();
$promise->catch(sub { push @errors, @_ })->wait;
is_deeply \@errors, ['foo'], 'promise rejected';
$promise  = Mojo::Promise->reject('foo');
$promise2 = Mojo::Promise->reject($promise);
isnt refaddr($promise2), refaddr($promise), 'different object';
@errors = ();
$promise2->catch(sub { push @errors, @_ })->wait;
is_deeply \@errors, ['foo'], 'promise rejected';

to:

subtest 'Promisify' => sub {
  is ref Mojo::Promise->resolve('foo'), 'Mojo::Promise', 'right class';

  $promise = Mojo::Promise->reject('foo');
  is ref $promise, 'Mojo::Promise', 'right class';
  @errors = ();
  $promise->catch(sub { push @errors, @_ })->wait;
  is_deeply \@errors, ['foo'], 'promise rejected';

  $promise = Mojo::Promise->resolve('foo');
  is refaddr(Mojo::Promise->resolve($promise)), refaddr($promise),
    'same object';

  $promise = Mojo::Promise->resolve('foo');
  isnt refaddr(Mojo::Promise->new->resolve($promise)), refaddr($promise),
    'different object';

  $promise = Mojo::Promise->reject('foo');
  is refaddr(Mojo::Promise->resolve($promise)), refaddr($promise),
    'same object';
  @errors = ();
  $promise->catch(sub { push @errors, @_ })->wait;
  is_deeply \@errors, ['foo'], 'promise rejected';

  $promise  = Mojo::Promise->reject('foo');
  $promise2 = Mojo::Promise->reject($promise);
  isnt refaddr($promise2), refaddr($promise), 'different object';
  @errors = ();
  $promise2->catch(sub { push @errors, @_ })->wait;
  is_deeply \@errors, ['foo'], 'promise rejected';
};

Block comments become the subtest description, and then we add a blank line in between unrelated test cases within the subtest. Here is another example.

[kraih]

And you don't have to convert all tests at once, one PR per test file should be fine.

[kraih]

We've converted promise.t in its entirety first, so there is an example for what's expected.

[kraih]

And cgi.t has been converted so there's an example for a test with lite app.

[kraih]

Since we keep linking to the issue, it is probably worth mentioning that all new code should always use subtests. Even if the test file it is added to has not been converted yet.