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Feature request: enforce generic types when passed to `ReactFireOptions`

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
45/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
firebase, react, typescript
Domain
frontend

Research direction

Start by searching the TypeScript sources for the ReactFireOptions interface and the occurrences of {[key: string]: unknown}. Update the option types so explicit generics constrain initialData and startWithValue, replace the applicable index signatures with Record<string, unknown>, and verify that mismatched generic values are rejected while untyped options remain usable.

Written by the indexing model from the issue text.

Description

v5
Enforce generic types when passed to ReactFireOptions, update various types

Hey guys, will try to keep this short. Right now ReactFireOptions is generic on T but the type of initialData, which should be only of_ type T is of type T | any.

export interface ReactFireOptions<T = unknown> {
  idField?: string;
  initialData?: T | any;
  /**
   * @deprecated use initialData instead
   */
  startWithValue?: T | any;
  suspense?: boolean;
}

The result of this is that the generic parameter is useless, as we don't get any type enforcement on initialData. For example, this is fine:

interface MyInterface {
    thing: string;
}

const foo: ReactFireOptions<MyInterface> = {
    initialData: {
        thing: 2 // no complaints
    }
}

My suggestion is to change ReactFireOptions to this:

export interface ReactFireOptions<T = any> {
  idField?: string;
  initialData?: T;
  /**
   * @deprecated use initialData instead
   */
  startWithValue?: T;
  suspense?: boolean;
}

This still allows users to pass whatever they want to initialData when not supplying a generic type, but will cause Typescript to complain when using a generic type and the value passed to initialData does not match the provided type.

interface MyInterface {
    thing: string;
}

const foo: ReactFireOptions<MyInterface> = {
    initialData: {
        thing: 2 // complains, "Type 'number' is not assignable to type 'string'."
    }
}

Additionally, there are a few places using { [key: string]: unknown }, which can be expressed more clearly with Record<string, unknown>.

I have a branch with the following changes but I can't push it as I don't have permissions. Not sure if I need to ask for them somewhere.

Cheers! Great project, and I'm finding it very useful.

Dominant language
TypeScript
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Forks
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Avg merge
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Merged PRs (30d)
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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

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