Add support for nested ZodEffects

[sassanh]

Relevant: #1319

This extends what was done in #1319 so that it works when multiple refinements are added, for example:

const schema = z
  .object({
    username: z.string().min(4),
    password: z.string().min(8),
    confirmPassword: z.string().min(8),
  })
  .refine((form) => form.password === form.confirmPassword, {
    message: "Passwords don't match",
    path: ["confirmPassword"],
  })
  .refine((form) => form.password !== form.username, {
    message: "Password is the same as the username",
    path: ["password"],
  });

@piotrpospiech can you kindly take a look?
Do you think we can have it in version 4? It doesn't look like a new feature.

[piotrpospiech]

Hi @sassanh, thanks for the contribution! It seems we can add it to the upcoming 4 or 4.x version. I will come back with detailed answer and review next week.

[piotrpospiech]

Hi @sassanh, great job with this pull request. Thanks for your input and adding new tests for the chained refine and superRefine functions.

Once those minor adjustments are made, we’ll be glad to proceed with the merge.

[piotrpospiech]

Suggested change

	schema: ZodObject<T> | NestedZodEffect<ZodObject<T>>;
	schema: ZodObject<T> | ZodEffects<ZodSchema>

We decided we don't want to create a special type with depth limit to handle this. ZodEffects<ZodSchema> will allow nested ZodEffects type. It will be easier to understand, maintain and we don't want to hardcode specific depth limit.

The downside is that it ZodSchema allows any zod type. This is something that we need to accept.

Wrong type is still checked using invariant function in the runtime.

[sassanh]

Hi @piotrpospiech, thanks for taking the time to review this!

I've made the changes you suggested in the comments. However, regarding your decision to avoid introducing a new type, I wanted to clarify that it does have a trade-off. The error objects returned by bridge.getValidator()(...) will be of type any.

Personally, I use Zod because it perfectly aligns with type hints. If I weren't using Zod, I'd use Yup, which is already supported by many libraries.