hasOneThrough failing during numerous model testing on MySQL

[JasonTheAdams]

• Laravel Version: 5.8.19
• PHP Version: 7.3.2
• Database Driver & Version: MySQL 8.0.15

Description:

I'm having a very strange issue wherein testing a hasOneThrough relationship is passing when I run the test individually, but when I run it as a suite of other tests it fails. To be clear, the suite is a bunch of unit tests that for model classes. Each test class uses the RefreshDatabase trait, so no two tests should affect one another.

Steps To Reproduce:

Here is my test:

    public function testShouldRetrieveCampaign()
    {
        $user     = factory(User::class)->create();
        $team     = factory(Team::class)->create(['owner_id' => $user->id]);
        $campaign = factory(Campaign::class)->create(['team_id' => $team->id]);
        $donation = factory(Donation::class)->create(['user_id' => $user->id, 'campaign_id' => $campaign->id]);
        $comment  = factory(DonationComment::class)->create(['donation_id' => $donation->id]);

        $this->assertTrue($comment->donation->campaign->is($campaign)); // works
        $this->assertTrue($comment->campaign->is($campaign)); // fails
    }

Couple very important things to note here:

• When the test is run individually it passes; it only fails when I run all the model tests.
• See the "works" and "fails" lines in the test. The "works" line works every time and is simply retrieving the middle model explicitly. The "fails" line is using a hasOneThrough eloquent relationship is the proper test. This is critical as it means that it's the hasOneThrough that's the issue.

[JasonTheAdams]

I just updated to Laravel 5.8.32 to see if this has been fixed between versions, and unfortunately the problem persists.

[staudenmeir]

Please create a fresh Laravel installation, add the code necessary to reproduce the issue and upload it to GitHub.

[JasonTheAdams]

@staudenmeir Will do. Few more notes on my current repo.

I stopped any previous tests from running. So long as this class' tests were the first, they worked fine. I added one test in a previous class with a simple $this->assertTrue(true) and it worked fine. But then I added the following:

public function testBreakage()
{
  factory(User::class)->create()
}

This caused the test to fail wherein the DonationComment accesses the User as a hasOneThrough. So it seems as though something about has a pre-existing model of the same kind that's trying to be retrieved via hasOneThrough causes it to fail.

But here's another interesting detail: This only seems to be an issue between test classes, as I'm creating users in the same class as the failing one, but when I run all tests within the test class then everything passes.

So the problem can currently be described as: When another test class creates a model that is the same as the model being retrieved via hasOneThrough, it causes that relationship to break.

---

Lastly, I'll note that I haven't seen this issue occur in production code, only in the tests.

[driesvints]

Hey there,

Can you first please try one of the support channels below? If you can actually identify this as a bug, feel free to report back and I'll gladly help you out and re-open this issue.

• Laracasts Forums
• Laravel.io Forums
• StackOverflow
• Discord
• Larachat
• IRC

Thanks!

[JasonTheAdams]

@driesvints Please reopen this issue. I've reproduced the bug in a fresh Laravel installation with minimal setup: https://github.com/JasonTheAdams/laravel-hasonethrough-bug

[driesvints]

@JasonTheAdams can you please try a support channel from above first?

[JasonTheAdams]

@driesvints Could you please provide some direction as to what I should get support for? I've reproduced the bug in a minimal state. Should I get some others to test it out and confirm it? I'm just not sure what you're asking me to do.

[driesvints]

@JasonTheAdams we haven't had reports of this up until now which is why I suspect there's something amis in your app that's causing this. Maybe letting others also reproduce it first can definitely help in confirming the bug.

[JasonTheAdams]

@driesvints I appreciate your suspicion and it makes sense. I reached out on Discord and I'll try to get some other folks to look at it. If you have 10 minutes, the repo I made is very bare bones, so if I am doing something odd it should be quickly obvious.

[driesvints]

@JasonTheAdams just a small fyi: if you ever run in a situation again where you need to create a repo to show a bug try to commit the skeleton first and then all your changes which reproduce the bug. That really helps to find out what's amis.

[driesvints]

@jason not 100% sure but your Donation doesn't has a relationship to the user so not sure how that would work in the first place?

[JasonTheAdams]

@driesvints Yeah, good call on committing the skeleton first. I'll keep that in mind in the future.

The donation table has a relationship, and the hasOneThrough doesn't require a middle model relationship as it just creates a double-join query under the hood. The donation table does have a user_id column, which is used for the join.

I did just learn one fun fact from someone on Discord — which I verified — the issue goes away when I run the tests using SQLite. Otherwise I've been using MySQL 8.0.15, which leads me to believe that's where the issue is.

[JasonTheAdams]

I'm really not even sure where to go by this point. I just tested MySQL 5.7.26 and the issue happened there as well. It doesn't seem to occur with hasManyThrough, either. 😕

[JasonTheAdams]

@driesvints Have any recommendations on how to proceed? I've reproduced the problem on vanilla Laravel and have narrowed it down to MySQL in some form (since SQLite works).

[staudenmeir]

The relationship is incorrect:

class Comment extends Model
{
    public function user()
    {
        return $this->hasOneThrough(
            User::class, Donation::class, 'id', 'id', 'donation_id', 'user_id'
        );
    }
}

Take a look at the executed query with the original relationship: The test only "worked" because the user and the donation have the same id.

[JasonTheAdams]

@staudenmeir Are you kidding!?

Oh man... thank you. I can't believe all of this was the result of me just not using the method properly and getting stuck behind a terrible coincidence.

I sincerely thank you for taking the time to point me in the right direction. I shall now eat my big piece of humble pie and move onto the next task.

[driesvints]

@JasonTheAdams this is the reason why you should try a support channel first. Don't get me wrong, we're happy to help but a lot of these things can be solved by help from the community. If we had to provide support for every single issue a community member has than we would be doing support for that 24/7 😅

Anyway, glad you found it 👍