Any reason to keep "@types/core-js" defined in "dependencies" section? It breaks AngularCompilerPlugin with TypeScript-based webpack config

[vladimiry]

Case

Failed to compile Angular project using AngularCompilerPlugin from @ngtools/webpack module having rxdb dependency added.

I go with TypeScript-based webpack configs files, most developers don't, so they don't notice this issue. For example, Angular CLI still goes with JS based configs. I also have no tsconfig.json=>compilerOptions.skipLibCheck option enabled. So a workaround is to enable skipLibCheck compilation option, which disables declaration files checking.

Issue

node_modules/@types/core-js/index.d.ts pollutes a global declarations scope. This is ok if you add this development time dependency explicitly as a developer. But this project leaves no choice having @types/core-js defined as a runtime dependency (dependencies section).

Info

• Environment: irrelevant
• Adapter: irrelevant
• Stack: (Typescript, Angular)

Here is error stack trace output:

ERROR in node_modules/@angular-devkit/core/src/utils/partially-ordered-set.d.ts(21,5): error TS2416: Property 'forEach' in type 'PartiallyOrderedSet<T>' is not assignable to the same property in base type 'Set<T>'.
  Type '(callbackfn: (value: T, value2: T, set: PartiallyOrderedSet<T>) => void, thisArg?: any) => void' is not assignable to type '(callbackfn: (value: T, value2: T, set: Set<T>) => void, thisArg?: any) => void'.
    Types of parameters 'callbackfn' and 'callbackfn' are incompatible.
      Types of parameters 'set' and 'set' are incompatible.
        Type 'PartiallyOrderedSet<T>' is not assignable to type 'Set<T>'.
          Property 'toJSON' is missing in type 'PartiallyOrderedSet<T>'.

There is such code in /node_modules/@angular-devkit/core/src/utils/partially-ordered-set.d.ts

export declare class PartiallyOrderedSet<T> implements Set<T> {
    private _items;
    protected _checkCircularDependencies(item: T, deps: Set<T>): void;
    clear(): void;
    has(item: T): boolean;
    readonly size: number;
    forEach(callbackfn: (value: T, value2: T, set: PartiallyOrderedSet<T>) => void, thisArg?: any): void;
    /**
     * Returns an iterable of [v,v] pairs for every value `v` in the set.
     */
    entries(): IterableIterator<[T, T]>;
    /**
     * Despite its name, returns an iterable of the values in the set,
     */
    keys(): IterableIterator<T>;
    /**
     * Returns an iterable of values in the set.
     */
    values(): IterableIterator<T>;
    add(item: T, deps?: (Set<T> | T[])): this;
    delete(item: T): boolean;
    [Symbol.iterator](): IterableIterator<T>;
    readonly [Symbol.toStringTag]: 'Set';
}

PartiallyOrderedSet implements the Set interface, but there is no toJSON method implemented, while node_modules/@types/core-js/index.d.ts forces toJSON to be implemented.

So is there any reason why @types/core-js is put as a runtime dependency, rather than dev dependency (devDependencies section)?

[pubkey]

Hi @vladimiry Thanks for pointing this out. I do not see a reason why we need @types/core-js in the dependencies. I can also not remember why I added it :)

[vladimiry]

Thanks for a fast response. Would like to see @types/core-js moved to devDependencies section or removed then.