Cannot create multiple errors response when generate Document

[huyhoang160593]

So the thing it in the doc there are mention to create custom response here https://github.com/RobinTail/express-zod-api#response-customization. But you can only create 1 schema for 1 negative response, but if I want to create multiple errors like 400 for validate and 401 for authorization, there is no way to define that. How can I utilize the custom response to have multiple entries of error in the same result handler?

[RobinTail]

Hello @huyhoang160593
The cause for a negative response is an Error.
Every error has a reason, which is is supposed to be expressed in its message property.
Surely, there can be custom errors that extend Error with additional properties and metadata.
You can create a schema for a negative response that covers those scenarios.

Consider discriminated union schema for that purpose:

const negativeResponseSchema = z.discriminatedUnion("cause", [
  z.object({ cause: z.literal("validation"), message: z.string() }),
  z.object({ cause: z.literal("authorization"), details: z.object({ ...}) }),
]);

However, the generated documentation currently is designed for a single negative schema that does not depend on particular faulty status code. It's purpose was to illustrate what the negative payload could be, but not to differentiate between 400 and 401.

This could probably be improved later, but so far a nice way is not yet invented.

[RobinTail]

@huyhoang160593 , would you be interested in helping me to test the feature #1431 ?

[RobinTail]

but the typescript is not so happy about the code

I checked it, @huyhoang160593
This is because you have mixed syntax in your Result Handler:

• Your getNegativeResponse returns an array (the featured syntax),
• While your getPositiveResponse (which appears to me a bit overcomplicated) returns different schemas (not array, previous syntax).

Those syntaxes can not be mixed, because overloads was the only way to introduce the feature.

So, in order to resolve the issue, those methods should both return EITHER arrays OR not arrays.
When I wrapped each of your return statements of getPositiveResponse with [{ schema: ... }], that fixed the issue:

Try it yourself and thank you for informing me.

[RobinTail]

Good news, @huyhoang160593 .
I think I found a way to improve my implementation to enable mixing like in your case.

[RobinTail]

@huyhoang160593 , I published version 16.2.0-beta2, please try it with your code as is — it should work.
Now it checks programmatically if the array of possible response schemas is not empty.
Please let me know how it works. Thank you

[huyhoang160593]

@RobinTail omg thank you for the hard work, I'm very appreciate it, this work wonderfully in my repo now

[RobinTail]

Great, I'm glad to read it, @huyhoang160593 .
Thank you as well for participating in the testing.
I could not came up with such use cases myself.
I'm going to await for one more test of this version by Dan Clayton in discussion #1193, and then make a stable release.

[RobinTail]

For those looking for a solution to the same problem,
the feature is available in version 16.2.0 🚀 — see Changelog for details.