diff --git a/tests/phpunit/tests/adminbar.php b/tests/phpunit/tests/adminbar.php
index 5a611fd72aac6..c20c9459141ff 100644
--- a/tests/phpunit/tests/adminbar.php
+++ b/tests/phpunit/tests/adminbar.php
@@ -939,4 +939,86 @@ public function test_menu_property_is_defined() {
 		$this->assertTrue( isset( $admin_bar->menu ), 'WP_Admin_Bar::$menu should be set.' );
 		$this->assertSame( array(), $admin_bar->menu, 'WP_Admin_Bar::$menu should be equal to an empty array.' );
 	}
+
+	/**
+	 * Tests that the Shortlink node is not added when shortlink is empty.
+	 *
+	 * @ticket 66223
+	 *
+	 * @covers ::wp_admin_bar_shortlink_menu
+	 */
+	public function test_wp_admin_bar_shortlink_menu_does_not_add_node_when_shortlink_is_empty() {
+		$this->go_to( home_url( '/' ) );
+		$this->assertFalse( is_singular(), 'Precondition: the query should not be singular.' );
+
+		$admin_bar = new WP_Admin_Bar();
+
+		wp_admin_bar_shortlink_menu( $admin_bar );
+
+		$node = $admin_bar->get_node( 'get-shortlink' );
+
+		$this->assertNull( $node, 'The Shortlink node should not be added when shortlink is empty.' );
+	}
+
+	/**
+	 * Tests that the Shortlink node is added when a shortlink exists.
+	 *
+	 * @ticket 66223
+	 *
+	 * @covers ::wp_admin_bar_shortlink_menu
+	 */
+	public function test_wp_admin_bar_shortlink_menu_adds_node_when_shortlink_exists() {
+		$post_id  = self::factory()->post->create();
+		$expected = home_url( '?p=' . $post_id );
+
+		$this->go_to( get_permalink( $post_id ) );
+
+		$admin_bar = new WP_Admin_Bar();
+		wp_admin_bar_shortlink_menu( $admin_bar );
+		$node = $admin_bar->get_node( 'get-shortlink' );
+
+		$this->assertNotNull( $node, 'The Shortlink node should be added when shortlink exists.' );
+		$this->assertSame( $expected, $node->href, 'The node href should be the post shortlink.' );
+		$this->assertSame( 'Shortlink', $node->title, 'The node title should be "Shortlink".' );
+		$this->assertStringContainsString(
+			'value="' . esc_attr( $expected ) . '"',
+			$node->meta['html'],
+			'The node HTML should contain the shortlink as the input value.'
+		);
+		$this->assertStringContainsString(
+			'aria-label="Shortlink"',
+			$node->meta['html'],
+			'The node HTML should contain "Shortlink" as the aria label.'
+		);
+	}
+
+	/**
+	 * Tests that the Shortlink node escapes the shortlink value in the HTML input value.
+	 *
+	 * @ticket 66223
+	 *
+	 * @covers ::wp_admin_bar_shortlink_menu
+	 */
+	public function test_wp_admin_bar_shortlink_menu_escapes_shortlink_in_input_value() {
+		$expected = home_url( '?test="first"&coverage="second"' );
+
+		add_filter(
+			'pre_get_shortlink',
+			static function () {
+				return home_url( '?test="first"&coverage="second"' );
+			}
+		);
+
+		$admin_bar = new WP_Admin_Bar();
+		wp_admin_bar_shortlink_menu( $admin_bar );
+
+		$node = $admin_bar->get_node( 'get-shortlink' );
+
+		$this->assertNotNull( $node, 'The Shortlink node should be added when a shortlink exists.' );
+		$this->assertStringContainsString(
+			'value="' . $expected . '"',
+			$node->meta['html'],
+			'The node HTML should contain the properly escaped shortlink in the input value.'
+		);
+	}
 }