phpspec / prophecy

     *

     * @throws \Prophecy\Exception\InvalidArgumentException

     */

    public function will($promise)

    {

        if (is_callable($promise)) {

            $promise = new Promise\CallbackPromise($promise);

        }

        if (!$promise instanceof Promise\PromiseInterface) {

            throw new InvalidArgumentException(sprintf(

                'Expected callable or instance of PromiseInterface, but got %s.',

                gettype($promise)

            ));

        }

        $this->bindToObjectProphecy();

        $this->promise = $promise;

        return $this;

    }

    /**

     * Sets return promise to the prophecy.

     *

     * @throws \Prophecy\Exception\InvalidArgumentException

     */

    public function should($prediction)

    {

        if (is_callable($prediction)) {

            $prediction = new Prediction\CallbackPrediction($prediction);

        }

        if (!$prediction instanceof Prediction\PredictionInterface) {

            throw new InvalidArgumentException(sprintf(

                'Expected callable or instance of PredictionInterface, but got %s.',

                gettype($prediction)

            ));

        }

        $this->bindToObjectProphecy();

        $this->prediction = $prediction;

        return $this;

    }

    /**

     * Sets call prediction to the prophecy.