Style Guide

Model

export interface Gizmo {
  readonly description: string;
  readonly id: string;
  readonly name: string;
}

Action

// tslint:disable:max-classes-per-file
import { Action } from "@ngrx/store";

import { Gizmo } from "./gizmo.model";

export enum GizmoActionTypes {
  //
  DATABASE_DELETE_ITEM = "[Gizmo] (Database) Delete Item",
  DATABASE_LISTEN_FOR_ADDED_ITEMS = "[Gizmo] (Database) Listen For Added Items"
}

export class DatabaseDeleteItem implements Action {
  public readonly type = GizmoActionTypes.DATABASE_DELETE_ITEM;

  constructor(public payload: { id: string; userId: string }) {}
}

export class DatabaseListenForAddedItems implements Action {
  public readonly type = GizmoActionTypes.DATABASE_LISTEN_FOR_ADDED_ITEMS;
}

export type GizmoActions = DatabaseDeleteItem | DatabaseListenForAddedItems;

https://angular.io/guide/styleguide#interfaces

Do name an interface using upper camel case.

Consider naming an interface without an I prefix.

Consider using a class instead of an interface for services and declarables (components, directives, and pipes).

Consider using an interface for data models.

Why? TypeScript guidelines discourage the I prefix.

Why? A class alone is less code than a class-plus-interface.

Why? A class can act as an interface (use implements instead of extends).

Why? An interface-class can be a provider lookup token in Angular dependency injection.