--- /dev/null
+<?php
+
+namespace Drupal\block\Tests;
+
+use Drupal\Component\Utility\Crypt;
+use Drupal\simpletest\WebTestBase;
+
+
+/**
+ * Tests form in block caching.
+ *
+ * @group block
+ */
+class BlockFormInBlockTest extends WebTestBase {
+
+ /**
+ * Modules to install.
+ *
+ * @var array
+ */
+ public static $modules = ['block', 'block_test', 'test_page_test'];
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function setUp() {
+ parent::setUp();
+
+ // Enable our test block.
+ $this->drupalPlaceBlock('test_form_in_block');
+ }
+
+ /**
+ * Test to see if form in block's redirect isn't cached.
+ */
+ public function testCachePerPage() {
+ $form_values = ['email' => 'test@example.com'];
+
+ // Go to "test-page" and test if the block is enabled.
+ $this->drupalGet('test-page');
+ $this->assertResponse(200);
+ $this->assertText('Your .com email address.', 'form found');
+
+ // Make sure that we're currently still on /test-page after submitting the
+ // form.
+ $this->drupalPostForm(NULL, $form_values, t('Submit'));
+ $this->assertUrl('test-page');
+ $this->assertText(t('Your email address is @email', ['@email' => 'test@example.com']));
+
+ // Go to a different page and see if the block is enabled there as well.
+ $this->drupalGet('test-render-title');
+ $this->assertResponse(200);
+ $this->assertText('Your .com email address.', 'form found');
+
+ // Make sure that submitting the form didn't redirect us to the first page
+ // we submitted the form from after submitting the form from
+ // /test-render-title.
+ $this->drupalPostForm(NULL, $form_values, t('Submit'));
+ $this->assertUrl('test-render-title');
+ $this->assertText(t('Your email address is @email', ['@email' => 'test@example.com']));
+ }
+
+ /**
+ * Test the actual placeholders
+ */
+ public function testPlaceholders() {
+ $this->drupalGet('test-multiple-forms');
+
+ $placeholder = 'form_action_' . Crypt::hashBase64('Drupal\Core\Form\FormBuilder::prepareForm');
+ $this->assertText('Form action: ' . $placeholder, 'placeholder found.');
+ }
+
+}