tests: adds more tests regarding snapshots multiple

src/Concerns/Testable.php

@@ -62,6 +62,11 @@ trait Testable
      */
     private static ?Closure $__afterAll = null;
 
+    /**
+     * The list of snapshot changes, if any.
+     */
+    private array $__snapshotChanges = [];
+
     /**
      * Resets the test case static properties.
      */
@@ -331,6 +336,24 @@ trait Testable
         return ExceptionTrace::ensure(fn (): mixed => call_user_func_array(Closure::bind($closure, $this, $this::class), $arguments));
     }
 
+    /** @postCondition */
+    protected function __MarkTestIncompleteIfSnapshotHaveChanged(): void
+    {
+        if (count($this->__snapshotChanges) === 0) {
+            return;
+        }
+
+        if (count($this->__snapshotChanges) === 1) {
+            $this->markTestIncomplete($this->__snapshotChanges[0]);
+
+            return;
+        }
+
+        $messages = implode(PHP_EOL, array_map(static fn (string $message): string => '- $message', $this->__snapshotChanges));
+
+        $this->markTestIncomplete($messages);
+    }
+
     /**
      * The printable test case name.
      */