Resolve #2910445 "Add a warning"

Closes #2910445

tests/src/Functional/ReadOnlyConfigTest.php

@@ -141,4 +141,24 @@ class ReadOnlyConfigTest extends ReadOnlyConfigTestBase {
     $this->assertSession()->pageTextContains($this->message);
   }
 
+  /**
+   * Test the status page to ensure the correct message is displayed.
+   *
+   * @see https://www.drupal.org/project/config_readonly/issues/2910445
+   */
+  public function testModuleStatusPage() {
+    // Verify if we can successfully access file system route.
+    $status_url = Url::fromRoute('system.status');
+    $this->drupalGet($status_url);
+    $this->assertSession()->statusCodeEquals(200);
+    // Status page displays REQUIREMENT_WARNING because read-only is disabled.
+    $this->assertSession()->pageTextContains("The Config Read-only module is enabled but not active.");
+
+    // Switch forms to read-only.
+    $this->turnOnReadOnlySetting();
+    $this->drupalGet($status_url);
+    // Status page displays REQUIREMENT_INFO because read-only is enabled.
+    $this->assertSession()->pageTextContains("The Config Read-only module is enabled and active.");
+  }
+
 }