Add unit test coverage for auto_sizes_get_featured_image_attachment_id()

Author: mukeshpanchal27

plugins/auto-sizes/tests/test-improve-calculate-sizes.php

@@ -1487,6 +1487,19 @@ public static function data_post_featured_image_block_alignment(): array {
 		);
 	}
 
+	/**
+	 * Test that auto_sizes_get_featured_image_attachment_id() returns 0 when post_id is not found.
+	 *
+	 * @covers ::auto_sizes_get_featured_image_attachment_id
+	 */
+	public function test_auto_sizes_get_featured_image_attachment_id_returns_zero_for_zero_post_id(): void {
+		$this->assertSame(
+			0,
+			auto_sizes_get_featured_image_attachment_id( 0 ),
+			'Should return 0 when post_id is not found.'
+		);
+	}
+
 	/**
 	 * Filter the theme.json data to include relative layout sizes.
 	 *