Optional props with exactOptionalPropertyTypes=true

// 3rdparty type, cannot be changed
interface Foobar {
    foo: number,

    // due to exactOptionalPropertyTypes=true, undefined cannot be assigned
    bar?: string

    // there can be a lots of other optional props here
}

declare const input: Foobar;

const optional = 'foo' as string | undefined;

// This works, but what if there are many more optional types
const result = optional ? { ...input, bar: optional } : input;

// Maybe a new helper for Struct???
const result1 = Struct.setOptional(input, 'bar', optional);

// With pipe many optional props can be handled properly
const result2 = pipe(input, Struct.setOptional('bar', optional));

const FooBarSchema = Schema.Struct({
    foo: Schema.Number,
    bar: Schema.optional(Schema.String, { exact: true, as: 'Option' })
});

// { foo: number; bar?: string; }
type Encoded = Schema.Schema.Encoded<typeof FooBarSchema>

// { foo: number; bar: Option<string>; }
type Decoded = Schema.Schema.Type<typeof FooBarSchema>