type ChildUpdateFields within type UpdateData does not play nicely with nested interfaces

[ianspryn]

Describe your environment

• Operating System version: MacOS Monterey 12.6
• Firebase SDK version: 11.19.0
• Firebase Product: Firebase Admin
• Node.js version: 16.15.0
• NPM version: 8.5.5

Describe the problem

Steps to reproduce:

Create a simple environment to work with:

> npm init # go through the init steps
> npm install typescript # currently 4.9.4
> npm install firebase-admin # currently 11.4.0

Relevant Code:

Create a typescript file with the following:

interface UserSuccess {
    name: {
        first: string;
        last: string;
    };
}

interface UserFail {
    name: Name;
}

interface Name {
    first: string;
    last: string;
}

Note how both UserSuccess and UserFail are technically identical in structure.

When using the UpdateData type, you are able to traverse interface objects to update a specific field within Firebase. For example, something like this: docRef.update({ "name.first": "John" });

However, when working with an interface that has a nested Interface object, UpdateData, or more specifically, ChildUpdateFields within UpdateData, fails to generate the new expected type whenever there are interfaces with other interfaces.

Success:

const user: FirebaseFirestore.UpdateData<UserSuccess> = {
    "name.first": "John",
};

The IDE even shows a list of helpful and expected suggestions:

Failure:

const user: FirebaseFirestore.UpdateData<UserFail> = {
    "name.first": "John", // ERROR
};

This produces the following error:

Type '{ "name.first": string; }' is not assignable to type '{ name?: FieldValue | { first?: string | FieldValue | undefined; last?: string | FieldValue | undefined; } | undefined; }'.
  Object literal may only specify known properties, and '"name.first"' does not exist in type '{ name?: FieldValue | { first?: string | FieldValue | undefined; last?: string | FieldValue | undefined; } | undefined; }'.

Secondly, the IDE does not show the intersected keys like above in the success state.

Possible Solution

Look at the ChildUpdateFields type.

 export type ChildUpdateFields<K extends string, V> =
    V extends Record<string, unknown>
      ? AddPrefixToKeys<K, UpdateData<V>>
      : never;

Change unknown to any:

 export type ChildUpdateFields<K extends string, V> =
    V extends Record<string, any>
        ? AddPrefixToKeys<K, UpdateData<V>>
        : never;

Suddenly, all problems described above are fixed. On top of that, the IDE also shows helpful and expected suggestions.

UserFail now behaves the same as UserSuccess:

const user: FirebaseFirestore.UpdateData<UserFail> = {
    "name.first": "John", // no more errors
};

Proper suggestions are listed in the IDE:

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[lahirumaramba]

Hi @ianspryn, Cloud Firestore support is provided by the @google-cloud/firestore library. Therefore the easiest and most efficient way to get Firestore issues resolved is by directly reporting them at the nodejs-firestore GitHub repo.

I think this will be better addressed on the nodejs-firestore repo, instead of here.

Thanks!

[LaysDragon]

Bump into this issue too,with complex class definition its a problem unable to use dot notation with nested interface :/

[cherylEnkidu]

Hi @LaysDragon , the issue is fully aware by the team and is working on fix.