Allow runtimeValidation with custom mutators by passing Zod schema

[Inv1x]

Description

When using a custom mutator, runtimeValidation is completely bypassed (Code source).

Current behavior

override.fetch.runtimeValidation is ignored when custom mutator is passed

Proposed behavior

override.fetch.runtimeValidation is used and can be passed to custom mutator

Proposed solution

Pass the Zod schema as an additional parameter to the custom mutator:

// Current mutator signature
export const httpClient = async <T>(url: string, options?: RequestInit): Promise<T>

// Proposed: add optional schema parameter
export const httpClient = async <T>(
  url: string,
  options?: RequestInit,
  schema?: ZodSchema<T>
): Promise<T> => {
  const response = await fetch(...)
  const data = await response.json()
  return schema ? schema.parse(data) : data
}

This would allow users who need custom auth/headers/error handling to still benefit from runtime validation.

[melloware]

cc @soartec-lab since you just added this feature

[soartec-lab]

@Inv1x If you use a custom mutator, wouldn't it be better to parse it within the custom mutator?

[Inv1x]

@soartec-lab not sure, sounds like a bigger boilerplate and overhead on passing schemas related to specific API call