ErrorException: mb_strlen() expects parameter 1 to be string, object given

/** @test */
public function a_job_is_indexed_to_algolia()
{
$this->withoutExceptionHandling();
        Event::fake();
        Mail::fake();
        Mail::assertNothingSent();
        Search::assertEmpty();
        Storage::fake('media');

        $user = factory(User::class)->create();

        $job = $this->actingAs($user)
            ->post('/jobs', $this->validParams(['document' => UploadedFile::fake()->image('lumber.jpg')]))
            ->assertRedirect('/searchjobs');

	// The error occurs with the 'document' above

	Search::assertSynced($job);

Was wondering if anyone had tried to test using the Spatie Media-Library?

The challenge is sending a Laravel Scout toSearchableArray() index to algolia with $job details and the thumbnail path. If the media-library saved a path in the $job table this would be easy. However, that package uses separate Media table.

This package Sti3bas / laravel-scout-array-driver helps determine if the searchableArray() has been synced among many other handy assertions.

From what I gather above the error is expecting a 'document' file name. However, I'm at a loss with how to test creating a job and uploading a file.

Here's the controller which creates the job:

// JobsController.php
// validation
// saving job object

        // below takes job_id, stores media/documents which the path can later be retrieved and synced to Algolia
        foreach ($request->input('document', []) as $file) {
            $job->addMedia(storage_path('medialibrary/temp/' . $file))
                ->preservingOriginal()
                ->toMediaCollection('document', 'media');
        }