ConstructorParameters is not working for private constructors (and protected constructors)

TypeScript Version: 3.4
Search Terms: ConstructorParameters, private constructor

Code

class Foo
{ public constructor(a: number, b: boolean, c: string) { } }

class Bar
{ private constructor(a: number, b: boolean, c: string) { } }

type FooCtorArgs = ConstructorParameters<typeof Foo>;
type BarCtorArgs = ConstructorParameters<typeof Bar>;

Expected behavior:
BarCtorArgs is [number, boolean, string].

Actual behavior:
Error in line 8:
Type 'typeof Bar' does not satisfy the constraint 'new (...args: any) => any'. Cannot assign a 'private' constructor type to a 'public' constructor type.

Playground Link: https://www.typescriptlang.org/play/#src=class%20Foo%0D%0A%7B%20public%20constructor(a%3A%20number%2C%20b%3A%20boolean%2C%20c%3A%20string)%20%7B%20%7D%20%7D%0D%0A%0D%0Aclass%20Bar%0D%0A%7B%20private%20constructor(a%3A%20number%2C%20b%3A%20boolean%2C%20c%3A%20string)%20%7B%20%7D%20%7D%0D%0A%0D%0Atype%20FooCtorArgs%20%3D%20ConstructorParameters%3Ctypeof%20Foo%3E%3B%0D%0Atype%20BarCtorArgs%20%3D%20ConstructorParameters%3Ctypeof%20Bar%3E%3B

Use Case

Convenient factory pattern to mimic asynchronous object construction.

class Component
{
    public static async create(...args: ConstructorParameters<typeof Component>)
    {
        const component = new Component(...args);
        await component.initialize();
        return component;
    }

    private constructor(a: number, b: boolean, c: string)
    { /* stuff */ }

    private async initialize()
    { /* asynchronous setup */ }
}

Ideas for Solution

Allow visibility modifiers in interfaces. Yes, if you use an interface to outline the visible properties of an object to a user this makes no sense, but why not allow interfaces to be a flexible tool to specify internal rules of implementations? I think this problem could be solved, if the ConstructorParameters type could be defined like the following:

type ConstructorParameters<T extends {private new (...args: any[]): any}> = T extends new (...args: infer P) => any ? P : never;

Which is of course no allowed at the moment.

Commencez par la reproduction liée dans Playground et par le comportement de TypeScript 3.4 pour ConstructorParameters appliqué aux constructeurs private et protected. Identifiez les points d’entrée pertinents du compilateur et des tests de régression, puis établissez un comportement qui infère le tuple d’arguments du constructeur sans assouplir les vérifications de visibilité ; le travail est terminé lorsque l’exemple est vérifié par le système de types avec le tuple attendu et que la couverture empêche les régressions.