Laravel bail: stop validation on the first failure

Laravel ships with a deep set of validation rules, and most of the time they’re all you need. But the docs don’t surface everything — now and then the feature you want is sitting right there in the source, just undocumented. This is the story of one of those, and how it ended up in the framework.

The bug my tests didn’t catch

I had a user_id field with what looked like sensible rules: it had to be present, an integer, and unique in the users table.

$this->validate($request, [
    'user_id' => 'required|integer|unique:users,user_id',
]);

It worked in my own testing. Then QA typed letters into the field and got a database error instead of a clean validation message.

Here’s why. By default Laravel runs every rule on an attribute and collects all the failures. So with a non-integer value, required passed, integer failed — and unique still ran anyway, firing a SELECT against a column the schema only allows integers in. The query blew up before validation could return a tidy message. My first instinct was a custom rule to work around it.

The one-word fix

What I actually wanted was for validation to stop at the first failure on that attribute, so a broken value never reaches the unique query. At the time the clean way to do that wasn’t in the documentation — so I built it and opened a pull request against Laravel. It was merged, and shipped in Laravel 5.2 as the bail rule:

$this->validate($request, [
    'user_id' => 'bail|required|integer|unique:users,user_id',
]);

With bail first, the moment required or integer fails, Laravel stops and never runs unique — no stray query, no database error. Two things to remember:

• Order matters. Rules run top to bottom, so put the cheap, structural checks (required, integer) before the ones that hit the database (unique, exists).
• bail is per-attribute. It only short-circuits the field it’s on; other fields still validate normally.

Still true today

Ten years on, bail is still the idiomatic answer, and it reads even better with the array syntax most Laravel code uses now:

use Illuminate\Validation\Rule;

$request->validate([
    'user_id' => ['bail', 'required', 'integer', Rule::unique('users', 'user_id')],
]);

That’s the whole trick — one small rule that turns a leaky “run everything” pass into a clean “stop when it breaks” one. It’s also a nice reminder that the frameworks we lean on every day are just code, and open enough to fix when they come up short.

Love Laravel. Keep coding.

— JJ