Start server function validator only supports the ValidatorFn shape (so things like Zod don't work as expected)

[marbemac]

Which project does this relate to?

Start

Describe the bug

On the Start v1.81.7, the server function validator middleware does not actually support the options described by its typings.

It accepts AnyValidator (https://github.com/TanStack/router/blob/main/packages/react-router/src/validators.ts#L62-L67).

However, the actual implementation assumes the validator is the ValidatorFn shape (https://github.com/TanStack/router/blob/main/packages/start/src/client/createServerFn.ts#L325-L330).

Looks like nextMiddleware.options.validator in that createServerFn.ts has the any type - any ways to cleanup the types in there as well? If nextMiddleware.options.validator were set to AnyValidator, the issue would have been surfaced right away.

Your Example Website or App

NA

Steps to Reproduce the Bug or Issue

Attempt to use zod, or zod + @tanstack/zod-adapter, with a server function validator and it'll throw.

Expected behavior

The server function validator supports the validator shapes described in @tanstack/zod-adapter.

Screenshots or Videos

No response

Platform

• OS: mac
• Browser: chrome

Additional context

No response

[schiller-manuel]

do you have a minimal example that we can use to debug this?

[marbemac]

@schiller-manuel looks like router already has a validateSearch function that handles the various validator shapes, but it's not exported. Could maybe re-use that?

Re example - can use the @tanstack/zod-adapter in any of the examples. I reproduced it by changing https://github.com/TanStack/router/blob/main/examples/react/start-basic-react-query/app/utils/posts.tsx#L28 to .validator(zodValidator(z.string())) (and add zod + @tanstack/zod-adapter to the package.json of course). Then fire up the example and navigate to the post route.

[schiller-manuel]

thanks.
yes we will probably reuse this from router.
if you want, you can also create a PR for this

[marbemac]

Happy to - will open it shortly. Just wanted to confirm ya'll are OK exporting and re-using that function from router - exporting it kind of makes it part of the "public" api surface in a way.

[schiller-manuel]

exporting it does not really mean it is public API IMO. it's public when we add API docs (which we don't do here)

[tannerlinsley]

I just pushed a "mostly" fix for this, but as we've been discussing the adoption of the "Standard Validation" schema internally, it might need to be massaged for backwards compatibility.

[marbemac]

Ah ok I see you copied over the validateSearch code rather than re-use from router - is intent over time for the validation interface to remain consistent across router and start? If so, maybe re-use rather than copy so that they don't diverge and to make that connection clear?

Either way, the pushed change did resolve the issue :).

There's a type error though that will likely block the build process.

[marbemac]

Getting familiar with the typings for functions / middleware's will take me longer than I have right now, but just one more pitch to somehow get things like nextMiddleware.options.validator typed correctly if possible - even though it's internal, would help to catch this kind of issue in the future especially as there is so much code churn happening in Start atm. I know ya'll have a lot on your plate though and it's prob low priority which is ok.

[tannerlinsley]

Yeah, I'm currently upgrading TanStack.com to this new version, so I feel the same pain. @chorobin is on vaycay, but is the most familiar with this code. I'm sure he can whip up a proper fix when he gets back. Let's let him rest. To your other question, yes, the plan is to support the standard validation schema format and also provide some fallback adapters that not only work across Start and Router, but also Form, etc.

[tannerlinsley]

Also, if you know how to fix the types, be my guest and PR. It's a high priority, but I just have so much on my plate right now I need to personally defer.

[marbemac]

Sounds good! Re the types I'll see if I can take a look but at first glance it looks like there's a high up front cost just to get familiar with the approach to types in router/start. Might not have enough time today, but perhaps in the next few days.

[schiller-manuel]

is this resolved with the latest releases?

[marbemac]

Yes, but Tanner mentioned "I'm sure he can whip up a proper fix when he gets back" so I wasn't sure if the current fix is temporary.

[schiller-manuel]

ok then let's keep this open until @chorobin is back

[schiller-manuel]

@chorobin told me to close this