feat(expect): adds toHaveProperty

src/Expectation.php

@@ -156,6 +156,16 @@ final class Expectation
         return $this;
     }
 
+    /**
+     * Assert that the $value contains the property $name.
+     */
+    public function toHaveProperty(string $name): Expectation
+    {
+        Assert::assertTrue(property_exists($this->value, $name));
+
+        return $this;
+    }
+
     /**
      * Asserts that two variables have the same value.
      *