Getters/setters are required when their corresponding type permits undefined, cannot be marked optional

[SelyankinFyodor]

Bug Report

It requires filed which is a getter and setter for optional filed in return value

🔎 Search Terms

getters setters existential type

🕗 Version & Regression Information

typescript version: 4.3.5

⏯ Playground Link

Playground link with relevant code

💻 Code

class innerProps {
    optfield1?: number;
    optfield2?: string;
}

class outerProp {
    __innerProps__?: innerProps;
    get innerProps(): innerProps | undefined {
        return this.__innerProps__;
    }
    set innerProps(value: innerProps | undefined) {
        this.__innerProps__ = value;
    }
    anotherOptionalProp?: number;
}

function failedFunc(): outerProp {
    return {anotherOptionalProp: 1};
}

🙁 Actual behavior

error: a required field is missing, although it is optional

🙂 Expected behavior

the returned object does not conflict with the declared type

[jcalz]

Aw, I got excited when I saw "existential type" but this issue has nothing to do with them.

although it is optional

The innerProps property is not optional. It must be present even if its value is undefined. There's currently no way to mark accessor properties as optional (see #14417) so there's no simple way to fix this code to make it behave the way you want. The code you wrote is working as intended, and if you're looking for a way to make innerProps optional then this is probably a duplicate of #14417.

_{😔 I want existential types so much}

[DanielRosenwasser]

It doesn't really make sense to distinguish a missing getter from | undefined because that get accessor will always be installed. You might be better off mirroring the type of your class and using optional properties.

[typescript-bot]

This issue has been marked 'Working as Intended' and has seen no recent activity. It has been automatically closed for house-keeping purposes.