(eslint-plugin): Propose updater-explicit-type-parameter ComponentStore rule

[LayZeeDK]

Which @ngrx/* package(s) are relevant/related to the feature request?

eslint-plugin

Information

I would like to suggest/contribute a ComponentStore ESLint rule. It would be an opt-in rule as it is a stylistic choices. What do you think?

updater-explicit-type-parameter

Updater should have a type parameter.

• Type: suggestion
• Fixable: No
• Suggestion: Yes
• Requires type checking: No
• Configurable: No

Rule Details

To have consistent code, we should explicitly add a type parameter.

Examples of incorrect code for this rule:

Value parameter type

interface MoviesState {
  movies: Movie[];
}

class MoviesStore extends ComponentStore<MoviesState> {
  readonly addMovie = this.updater((state, movie: Movie): MoviesState => ({
                    // ⚠ no type parameter passed
    movies: [...state.movies, movie],
  }));
}

No value parameter type

interface MoviesState {
  movies: Movie[];
}

class MoviesStore extends ComponentStore<MoviesState> {
  readonly addMovie = this.updater((state, movie): MoviesState => ({
                    // ⚠ no type parameter passed
    movies: [...state.movies, movie],
  }));
}

Examples of correct code for this rule:

Value parameter type

interface MoviesState {
  movies: Movie[];
}

class MoviesStore extends ComponentStore<MoviesState> {
  readonly addMovie = this.updater<Movie>((state, movie: Movie): MoviesState => ({
                    // ✅ type parameter passed
    movies: [...state.movies, movie],
  }));
}

No value parameter type

interface MoviesState {
  movies: Movie[];
}

class MoviesStore extends ComponentStore<MoviesState> {
  readonly addMovie = this.updater<Movie>((state, movie): MoviesState => ({
                    // ✅ type parameter passed
    movies: [...state.movies, movie],
  }));
}

Describe any alternatives/workarounds you're currently using

Without a lint rule enforcing one style, a codebase could have different variations of updater type definitions.

I would be willing to submit a PR to fix this issue

• Yes
• No