[8.x] Forget and clear a mocked/spied instance of an object in the co…

…ntainer (#39713)

* Forget and clear a mocked/pied instance of an object in the container

* Style Fix

* Test for forgetMock

* Update InteractsWithContainer.php

Co-authored-by: Taylor Otwell <taylor@laravel.com>

src/Illuminate/Foundation/Testing/Concerns/InteractsWithContainer.php

@@ -77,6 +77,19 @@ protected function spy($abstract, Closure $mock = null)
         return $this->instance($abstract, Mockery::spy(...array_filter(func_get_args())));
     }
 
+    /**
+     * Instruct the container to forget a previously mocked / spied instance of an object.
+     *
+     * @param  string  $abstract
+     * @return $this
+     */
+    protected function forgetMock($abstract)
+    {
+        $this->app->forgetInstance($abstract);
+
+        return $this;
+    }
+
     /**
      * Register an empty handler for Laravel Mix in the container.
      *

tests/Foundation/Testing/Concerns/InteractsWithContainerTest.php

@@ -27,4 +27,25 @@ public function testWithMixRestoresOriginalHandlerAndReturnsInstance()
         $this->assertSame($handler, resolve(Mix::class));
         $this->assertSame($this, $instance);
     }
+
+    public function testForgetMock()
+    {
+        $this->mock(IntanceStub::class)
+            ->shouldReceive('execute')
+            ->once()
+            ->andReturn('bar');
+
+        $this->assertSame('bar', $this->app->make(IntanceStub::class)->execute());
+
+        $this->forgetMock(IntanceStub::class);
+        $this->assertSame('foo', $this->app->make(IntanceStub::class)->execute());
+    }
+}
+
+class IntanceStub
+{
+    public function execute()
+    {
+        return 'foo';
+    }
 }