Add test for factory throwing an exception

Author: jsor

tests/React/Promise/LazyPromiseTest.php

@@ -63,4 +63,26 @@ public function shouldReturnPromiseIfFactoryReturnsNull()
         $p = new LazyPromise($factory);
         $this->assertInstanceOf('React\\Promise\\PromiseInterface', $p->then());
     }
+    
+    /** @test */
+    public function shouldReturnRejectedPromiseIfFactoryThrowsException()
+    {
+        $exception = new \Exception();
+        
+        $factory = $this->createCallableMock();
+        $factory
+            ->expects($this->once())
+            ->method('__invoke')
+            ->will($this->throwException($exception));
+
+        $errorHandler = $this->createCallableMock();
+        $errorHandler
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($this->identicalTo($exception));
+
+        $p = new LazyPromise($factory);
+
+        $p->then($this->expectCallableNever(), $errorHandler);
+    }
 }