Tests stylesheets-override and stylesheets-remove.
function testStylesheets() {
theme_enable(array(
'test_basetheme',
'test_subtheme',
));
config('system.theme')
->set('default', 'test_subtheme')
->save();
$base = drupal_get_path('theme', 'test_basetheme');
// Unlike test_basetheme (and the original module CSS), the subtheme decides
// to put all of its CSS into a ./css subdirectory. All overrides and
// removals are expected to be based on a file's basename and should work
// nevertheless.
$sub = drupal_get_path('theme', 'test_subtheme') . '/css';
$this
->drupalGet('theme-test/info/stylesheets');
$this
->assertRaw("{$base}/base-add.css");
$this
->assertRaw("{$base}/base-override.css");
$this
->assertNoRaw("base-remove.css");
$this
->assertRaw("{$sub}/sub-add.css");
$this
->assertRaw("{$sub}/sub-override.css");
$this
->assertRaw("{$sub}/base-add.sub-override.css");
$this
->assertRaw("{$sub}/base-remove.sub-override.css");
$this
->assertNoRaw("sub-remove.css");
$this
->assertNoRaw("base-add.sub-remove.css");
$this
->assertNoRaw("base-override.sub-remove.css");
}