Confirms that placeholders in paths work correctly.
public function testControllerPlaceholders() {
$value = $this
->randomName();
$this
->drupalGet('router_test/test3/' . $value);
$this
->assertRaw($value, 'The correct string was returned because the route was successful.');
// Confirm that the page wrapping is being added, so we're not getting a
// raw body returned.
$this
->assertRaw('</html>', 'Page markup was found.');
// In some instances, the subrequest handling may get confused and render
// a page inception style. This test verifies that is not happening.
$this
->assertNoPattern('#</body>.*</body>#s', 'There was no double-page effect from a misrendered subrequest.');
}