In one embodiment, a script executes code on a testing device to automatically control a control device. A media player on the control device interacts with a video streaming service. The testing device receives events from the control device based on the control device being controlled by the script to perform actions. The actions performed by the control device results in the events being asynchronously sent to the testing device. The events is then stored in the event buffer. The script initiates a wait for routine that waits for a target event to occur before execution of the script can continue and receives the events from the event buffer where the events are stored in the event buffer. The script then analyzes the events to determine if the target event occurred to allow the script to continue execution.