I am trying to mock the LaravelScoutBuilder class in one of my Pest tests with Mockery. The goal is to force the throwing of an exception to test my fallback code:

Controller

try {
    return self::search($term)->get();
} catch (Exception $e) {
   //Want to test code here is working well
}

The static search method eventually calls the following from within the LaravelScout package:

LaravelScoutBuilder

public static function search($query = '', $callback = null)
    {
        return app(static::$scoutBuilder ?? Builder::class, [
            'model' => new static,
            'query' => $query,
            'callback' => $callback,
            'softDelete' => static::usesSoftDelete() && config('scout.soft_delete', false),
        ]);
    }

Because the Builder::class is resolved using the app helper, I think I can mock it using the following in my tests:

Pest Test

$this->instance(LaravelScoutBuilder::class,
    Mockery::mock(LaravelScoutBuilder::class, function (MockInterface $mock) {
        $mock
            ->makePartial()
            ->shouldReceive('get')
            ->andThrow(new Exception('Search error'));
    })
);

However, the normal Builder class is used by my controller so the exception is never thrown and my code is not tested.

If I dump(app(static::$scoutBuilder ?? Builder::class)) without the constructor arguments then I do get an instance of the mocked class. But as the arguments in the array are passed I get an instance of the original class instead.

What do I need to change in my mock to get the behaviour I want? I have tried both with and without makePartial() with no change.