[8.x] Add model support for database assertions

[nuernbergerA]

Hey Guys!

A good thing when working with Eloquent, you never ever have to care about the table name.
But when it comes to testing there are some nice assertions assertDatabase*()

Currently, I have to "hardcode" the table name in my tests (which makes it hard to rename a model and its table name later) $this->assertDatabaseCount('users', 5);

Wouldnt it be great to just pass the model?
This PR adds exactly this!

$this->assertDatabaseCount('users', 5);
$this->assertDatabaseCount(Users::class, 5);
$this->assertDatabaseCount(new User, 5);

I know we could also resolve the connection from the model but this could be done in a follow-up PR.

Cheers Adrian

[Wulfheart]

This would be really helpful.

[bhushan]

Yes for sure, imagine in the model i have used custom table name, i dont have to remember it if it fetches automatically in the test based on class

[Wulfheart]

Does this also support things like assertDatabaseHas and assertDatabaseMissing?

[bhushan]

Yes @Wulfheart .. check PR ..