Add required fields and validation checks.

tests/src/Functional/SettingsTest.php

@@ -70,11 +70,39 @@ public function testSettingsForm(): void {
     // Check the values in fields.
     $this->drupalGet(Url::fromRoute('collabora-online.settings'));
     $assert_session->fieldValueEquals('Collabora Online server URL', 'http://collaboraserver.com/');
+    // Slash is removed at the end of Wopi URL.
     $assert_session->fieldValueEquals('WOPI host URL', 'http://wopihost.com');
     $assert_session->fieldValueEquals('JWT private key ID', 'a_random_token');
     $assert_session->fieldValueEquals('Access Token Expiration (in seconds)', '3600');
     $assert_session->fieldValueEquals('Disable TLS certificate check for COOL.', '1');
     $assert_session->fieldValueEquals('Allow COOL to use fullscreen mode.', '');
+
+    // Check required fields, set empty values and check errors displayed.
+    $this->drupalGet(Url::fromRoute('collabora-online.settings'));
+    $assert_session->fieldExists('Collabora Online server URL')->setValue('');
+    $assert_session->fieldExists('WOPI host URL')->setValue('');
+    $assert_session->fieldExists('JWT private key ID')->setValue('');
+    $assert_session->fieldExists('Access Token Expiration (in seconds)')->setValue('');
+    $assert_session->fieldExists('Disable TLS certificate check for COOL.')->uncheck();
+    $assert_session->fieldExists('Allow COOL to use fullscreen mode.')->uncheck();
+    $assert_session->buttonExists('Save configuration')->press();
+    $assert_session->statusMessageContains('Collabora Online server URL field is required.', 'error');
+    $assert_session->statusMessageContains('WOPI host URL field is required.', 'error');
+    $assert_session->statusMessageContains('JWT private key ID field is required.', 'error');
+    $assert_session->statusMessageContains('Access Token Expiration (in seconds) field is required.', 'error');
+    $assert_session->statusMessageNotContains('The configuration options have been saved.', 'status');
+
+    // Check validation for fields.
+    $this->drupalGet(Url::fromRoute('collabora-online.settings'));
+    // Set invalid value for URL fields.
+    $assert_session->fieldExists('Collabora Online server URL')->setValue('/internal');
+    $assert_session->fieldExists('WOPI host URL')->setValue('any-other-value');
+    // Set invalid values for numeric field.
+    $assert_session->fieldExists('Access Token Expiration (in seconds)')->setValue('text');
+    $assert_session->buttonExists('Save configuration')->press();
+    $assert_session->statusMessageContains('The URL /internal is not valid.', 'error');
+    $assert_session->statusMessageContains('The URL any-other-value is not valid.', 'error');
+    $assert_session->statusMessageNotContains('Access Token Expiration (in seconds) must be a number.', 'status');
   }
 
 }