Support for ZodIntersection (and maybe ZodUnion?)

[solomonhawk]

Similar to #25, if your schema is a z.intersection(schema1, schema2) or z.union([...schemas]), it won't work with the hook.

As you know, these schemas can get pretty complicated. In the case of intersection there are 2 branches of other zod types to collect fields from. Here's an initial stab that seems to work ok for my use case but could definitely be improved:

function getShapeFromZodType(schema: ZodType, shape: any = {}) {
  if (schema instanceof ZodObject) {
    for (const key of Object.keys(schema.shape)) {
      shape[key] = schema.shape[key]
    }

    return shape
  }

  if (schema instanceof ZodEffects) {
    return getShapeFromZodType(schema._def.schema, shape)
  }

  if (schema instanceof ZodIntersection) {
    return {
      ...getShapeFromZodType(schema._def.left, shape),
      ...getShapeFromZodType(schema._def.right, shape),
    }
  }
}

export function useFormInputProps(schema: ZodType) {
  const shape = getShapeFromZodType(schema)

  return function props(key: string) {
    const def = shape[key]
    if (!def) {
      throw new Error(`no such key: ${key}`)
    }
    return getInputProps(key, def)
  }
}

[kiliman]

Yes, my schema support really only handled the stuff I used or added due to other user requests.

I should go back and see if I can figure out a more general way to handle any zod schema.

[solomonhawk]

Unions are an interesting case - I don't think we can reasonably extract input props from any union, given the associated schemas could have conflicting rules.

We can handle Discriminated Unions but it requires passing in data (the current value of the discriminant). I actually have an implementation of this that works.