Adds an assertFocused method

src/Api/Concerns/MakesElementAssertions.php

@@ -13,6 +13,50 @@
  */
 trait MakesElementAssertions
 {
+    /**
+     * Assert that the given element is focused.
+     */
+    public function assertFocused(string $selector): Webpage
+    {
+        $selector = $this->guessLocator($selector)->selector();
+
+        $escapedSelector = json_encode($selector);
+
+        $isFocused = $this->page->evaluate("
+            () => {
+                const element = document.querySelector({$escapedSelector});
+                const focusedElement = document.activeElement;
+                return element && focusedElement ? element === focusedElement : false;
+            }
+        ");
+
+        expect($isFocused)->toBeTrue("Expected element [{$selector}] to be focused on the page [{$this->initialUrl}], but it was not.");
+
+        return $this;
+    }
+
+    /**
+     * Assert that the given element is not focused.
+     */
+    public function assertNotFocused(string $selector): Webpage
+    {
+        $selector = $this->guessLocator($selector)->selector();
+
+        $escapedSelector = json_encode($selector);
+
+        $isNotFocused = $this->page->evaluate("
+            () => {
+                const element = document.querySelector({$escapedSelector});
+                const focusedElement = document.activeElement;
+                return element && focusedElement ? element !== focusedElement : true;
+            }
+        ");
+
+        expect($isNotFocused)->toBeTrue("Expected element [{$selector}] not to be focused on the page [{$this->initialUrl}], but it was.");
+
+        return $this;
+    }
+
     /**
      * Assert that the page title matches the given text.
      */

tests/Browser/Webpage/AssertFocusedTest.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+it('assert an element is focused', function (): void {
+    Route::get('/', fn (): string => <<<'HTML'
+    <div>
+        <input type="text" name="firstname" id="firstname" data-test="firstname" autofocus />
+        <input type="text" name="lastname" id="lastname" data-text="lastname" />
+    </div>
+    HTML);
+
+    $page = visit('/');
+
+    $page->assertFocused('@firstname');
+    $page->assertNotFocused('@lastname');
+});