zod: Prisma XOR with Zod > 3.21.1 not working

We encounterd a bug when using generated prisma types with versions greater than 3.21.1.

You can reproduce the issue in the following repo: https://github.com/chrishoermann/zod-prisma-types-bug

As you can read in the following discussion we first thought it was an issue with prisma, but after digging around and finding that the suspected type has been this way for a long time now @njdowdy found that this is a zod issue that happend somwhere in 3.21.2

Discussed in https://github.com/colinhacks/zod/discussions/2171

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^{Originally posted by chrishoermann March 9, 2023} I’ve built a generator for prisma (zod-prisma-types) that throws a type error since prisma updated their XOR type in 4.11:

  type Without<T, U> = { [P in Exclude<keyof T, keyof U>]?: never };

  /**
   * XOR is needed to have a real mutually exclusive union type
   * https://stackoverflow.com/questions/42123407/does-typescript-support-mutually-exclusive-types
   */
  type XOR<T, U> =
    T extends object ?
    U extends object ?
      (Without<T, U> & U) | (Without<U, T> & T)
    : U : T

before this type update the following zod schema worked without problems:

export const UserCreateInputSchema: z.ZodType<Prisma.UserCreateInput> = z.object({
  id: z.string().cuid().optional(),
  email: z.string().email({ message: "Invalid email address" }),
  name: z.string().min(1).max(100).optional().nullable(),
  role: z.union([ z.lazy(() => UserCreateroleInputSchema),z.lazy(() => RoleSchema).array() ]).optional(),
  enum: z.lazy(() => AnotherEnumSchema).optional(),
  scalarList: z.union([ z.lazy(() => UserCreatescalarListInputSchema),z.string().array() ]).optional(),
  posts: z.lazy(() => PostCreateNestedManyWithoutAuthorInputSchema).optional(),
  profile: z.lazy(() => ProfileCreateNestedOneWithoutUserInputSchema).optional(),
  location: z.lazy(() => LocationCreateNestedOneWithoutUserInputSchema).optional(),
}).strict();

export const UserUncheckedCreateInputSchema: z.ZodType<Prisma.UserUncheckedCreateInput> = z.object({
  id: z.string().cuid().optional(),
  email: z.string().email({ message: "Invalid email address" }),
  name: z.string().min(1).max(100).optional().nullable(),
  role: z.union([ z.lazy(() => UserCreateroleInputSchema),z.lazy(() => RoleSchema).array() ]).optional(),
  enum: z.lazy(() => AnotherEnumSchema).optional(),
  scalarList: z.union([ z.lazy(() => UserCreatescalarListInputSchema),z.string().array() ]).optional(),
  lat: z.number(),
  lng: z.number(),
  posts: z.lazy(() => PostUncheckedCreateNestedManyWithoutAuthorInputSchema).optional(),
  profile: z.lazy(() => ProfileUncheckedCreateNestedOneWithoutUserInputSchema).optional(),
}).strict();

export const UserCreateArgsSchema: z.ZodType<Prisma.UserCreateArgs> = z.object({
  select: UserSelectSchema.optional(),
  include: UserIncludeSchema.optional(),
  data: z.union([ UserCreateInputSchema,UserUncheckedCreateInputSchema ]),
}).strict()

so a simple union was sufficient to satisfy typescript. in Prisma 4.11 typescript now throws the following error because, as I see it, the Without<...> type can not be satisfied with a union anymore:

Type 'ZodObject<{ select: ZodOptional<ZodType<UserSelect, ZodTypeDef, UserSelect>>; include: ZodOptional<ZodType<UserInclude, ZodTypeDef, UserInclude>>; data: ZodUnion<...>; }, "strict", ZodTypeAny, { ...; }, { ...; }>' is not assignable to type 'ZodType<UserCreateArgs, ZodTypeDef, UserCreateArgs>'.
  The types of '_type.data' are incompatible between these types.
    Type '(UserCreateInput | UserUncheckedCreateInput) & (UserCreateInput | UserUncheckedCreateInput | undefined)' is not assignable to type '(Without<UserCreateInput, UserUncheckedCreateInput> & UserUncheckedCreateInput) | (Without<...> & UserCreateInput)'.
      Type 'UserCreateInput & UserUncheckedCreateInput' is not assignable to type '(Without<UserCreateInput, UserUncheckedCreateInput> & UserUncheckedCreateInput) | (Without<...> & UserCreateInput)'.
        Type 'UserCreateInput & UserUncheckedCreateInput' is not assignable to type 'Without<UserUncheckedCreateInput, UserCreateInput> & UserCreateInput'.
          Type 'UserCreateInput & UserUncheckedCreateInput' is not assignable to type 'Without<UserUncheckedCreateInput, UserCreateInput>'.
            Types of property 'lat' are incompatible.
              Type 'number' is not assignable to type 'undefined'.

I’m currently a bit stuck on how to solve this issue because I don’t really know how to implement the Without<...> type especially because the z.ZodType<...> does not provide the object helper methods that would have been my first guess on how to approach this. Any help is appreciated.

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