Potential issue with model factories (Refactoring for speed)

[sileence]

I really enjoyed this lesson and I've been doing something similar, however I've spotted a potential issue when working with model factories: some of them might create new registers in the database, i.e.:

$factory->define(App\Message::class, function (Faker\Generator $faker) {
    return [
        'message' => $faker->sentence,
        'user_id' => function () {
            return factory(\App\User::class)->create()->id;
        },
    ];
});

What happens there? Should I assign a fake ID to avoid the creation of the user object?

[sileence]

That's exactly what the closure does @liefie, you don't need the ternary operator. But back to square one: we don't have an ID if we don't store the code in the database.

[liefie]

Learn something new every day!

I understand your question now, you're creating the user, but not creating the Message as you're going to call factory()->make();

Perhaps adding a state?

allowing $user->messages()->save(factory(App\Message::class)->make();, factory(App\Message::class)->make() and factory(App\Message::class)->states('withUser')->create();

$factory->define(App\Message::class, function (Faker\Generator $faker) {
    return [
        'message' => $faker->sentence,
    ];
});

factory->state(\App\Message::class, 'withUser', function(\Faker\Generator $faker) {
    return [
        'user_id' => function () {
            return factory(\App\User::class)->create()->id;
        },
    ];
});

[sileence]

That could be, although I don't like the extra effort. I'm thinking in sending a Pull request to Laravel that could solve this in another way, if another solution doesn't exist yet.

Maybe you could do:

$factory->define(App\Message::class, function (Faker\Generator $faker) {
    return [
        'message' => $faker->sentence,
        'user' => function () {
            return factory(\App\User::class)->create();
        },
    ];
});

Maybe if make() is called then all the relationships will be "made" as well instead of "created"

For now I'm just not using factories but manually calling new Message

[adamwathan]

If you are using create to create a Message, you'll likely want the User created as well, since a Message isn't really "valid" without an associated User, especially if you are enforcing foreign key constraints.

However, if you're using make to build an in-memory Message that doesn't need to be saved to the database for the purposes of the test, you can pass in an arbitrary user_id or create a state like @liefie suggested:

$message = factory(Message::class)->make(['user_id' => 0]);

...or using a state, you could do something like:

$factory->state(Message::class, 'stubbed', function () {
    return ['user_id' => 0];
});

$message = factory(Message::class)->states('stubbed')->make();

[sileence]

Thank you @adamwathan and @liefie. As I mentioned above I'm thinking in a built-in solution for Laravel, does that make sense?

[adamwathan]

@sileence I wrote a factory package many years ago that solved the problem the way you are proposing but haven't really maintained it since Laravel got it's own factories:

https://github.com/adamwathan/faktory#relationships-and-build-strategies

It's tricky to get it to always behave exactly as if the relationships were saved, so I haven't bothered with the approach much and instead just create what I need in the test database.

I wrote about a similar approach you can sometimes use here though:

https://adamwathan.me/2016/08/04/stubbing-eloquent-relations-for-faster-tests/

[sileence]

I'll see if I can come up with something, otherwise I'll follow your previous advice about the states!