create-lazy-effect.ts

import {Action, ActionCreator} from '@ngrx/store';
import {AbstractType, InjectionToken, Type} from '@angular/core';
import {Observable} from 'rxjs';

declare type DispatchType<T> = T extends {
    dispatch: infer U;
}
    ? U
    : true;
declare type ObservableType<T, OriginalType> = T extends false ? OriginalType : Action;
declare type InjectionType<T> = Type<T> | InjectionToken<T> | AbstractType<T>;

export interface LazyEffectConfig {
    /**
     * Determines if the action emitted by the effect is dispatched to the store.
     * If false, effect does not need to return type `Observable<Action>`.
     */
    dispatch?: boolean;
    /**
     * Determines if the effect will be resubscribed to if an error occurs in the main actions stream.
     */
    useEffectsErrorHandler?: boolean;
}

export function createLazyEffect<
    C extends LazyEffectConfig,
    DT extends DispatchType<C>,
    OT extends ObservableType<DT, OT>,
    R extends Observable<OT>,
    AC extends ActionCreator[],
    DEP1,
    DEP2,
    DEP3,
    DEP4,
    DEP5,
    DEP6,
    DEP7,
    DEP8,
    DEP9,
    V = ReturnType<AC[number]>
>(
    config: {
        actions: AC;
        effect: (action$: Observable<V>, ...dependencies: [DEP1, DEP2, DEP3, DEP4, DEP5, DEP6, DEP7, DEP8, DEP9]) => R;
        dependencies: Partial<
            [
                InjectionType<DEP1>,
                InjectionType<DEP2>,
                InjectionType<DEP3>,
                InjectionType<DEP4>,
                InjectionType<DEP5>,
                InjectionType<DEP6>,
                InjectionType<DEP7>,
                InjectionType<DEP8>,
                InjectionType<DEP9>,
            ]
        >;
    } & Partial<C>,
): any {
    return config;
}