Yup: Question: Concat with Typescript

[sngreg]

I am looking to to do something similar to the below code, but running into a typescript issue and was wondering if anyone has seen this or solved this?

const common = yup.object().shape({
  firstName: yup.string().required(),
});

const person = yup
  .object()
  .shape({
    lastName: yup.string().required(),
  })
  .concat(common);

Here is the issue that looks like it is based on types. Removing the .concat(common) solves this. In a real life example, the common schema would be concat to multiple schemas

No overload matches this call.
  Overload 1 of 2, '(schema: ObjectSchema<Shape<object | undefined, { lastName: string; }>>): ObjectSchema<Shape<object | undefined, { lastName: string; }>>', gave the following error.
    Argument of type 'ObjectSchema<Shape<object | undefined, { firstName: string; }>>' is not assignable to parameter of type 'ObjectSchema<Shape<object | undefined, { lastName: string; }>>'.
      Types of property 'fields' are incompatible.
        Type '{ firstName: Schema<string>; } | undefined' is not assignable to type '{ lastName: Schema<string>; } | undefined'.
          Property 'lastName' is missing in type '{ firstName: Schema<string>; }' but required in type '{ lastName: Schema<string>; }'.
  Overload 2 of 2, '(schema: ObjectSchema<object>): ObjectSchema<object & { lastName: string; }>', gave the following error.
    Argument of type 'ObjectSchema<Shape<object | undefined, { firstName: string; }>>' is not assignable to parameter of type 'ObjectSchema<object>'.
      Types of property 'fields' are incompatible.
        Type '{ firstName: Schema<string>; } | undefined' is not assignable to type 'object'.
          Type 'undefined' is not assignable to type 'object'.  TS2769

    13 |     lastName: yup.string().required(),
    14 |   })
  > 15 |   .concat(common);

I appreciate any time people take to look into this or provide a path forward.

[async3619]

add .required() method call.

I think Yup's type definition will add undefined as a intersection type since you didn't specify given object would always be not-null.

so below would be an answer code for your problem:

const common = yup.object().shape({
  firstName: yup.string().required(),
}).required(); // <--

const person = yup
    .object()
    .shape({
      lastName: yup.string().required(),
    })
    .required() // <--
    .concat(common);

[sngreg]

@async3619 - That worked great. I appreciate the quick response!

Closing out this question :)