TypeScript right adapt constructor

[little-alei]

🔍 Search Terms

I have implemented a function JavaAdapter to inherit classes and return instantiated objects. Now I'm creating a declaration for it.

type ProxyMethods<T extends object> = { [K in keyof T]?: T[K] } | {};

declare function JavaAdapter<T, K extends ProxyMethods<T>, Args>(
  className: new (...args: Args) => T,
  override: K,
  ...args: Args
): K & T;

In most cases, it works fine. However, when the inherited object has multiple constructor functions with different parameter counts, it cannot accurately match, for example:

JavaAdapter(
  android.widget.Button,
  {
    setOnClickListener(view) {
      console.log(view);
    },
  },
  activity,
  // new android.util.AttributeSet()
);

This usage is correct and matches one of the constructor functions, but TypeScript prompts "Expected 4 arguments, but got 3." It works only when I add new android.util.AttributeSet(). The partial declaration of android.widget.Button is as follows:

declare module android {
  export module widget {
    class Button {
      public setOnClickListener(view: this): void;
      public constructor(context: android.content.Context);
      public constructor(context: android.content.Context, attribute: android.util.AttributeSet);
    }
  }
}

Besides changing to constructor(context: android.content.Context, attribute?: android.util.AttributeSet);, can TypeScript better adapt?

✅ Viability Checklist

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
• This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

⭐ Suggestion

TypeScript matches correctly based on parameters

📃 Motivating Example

Enhance the user experience of typescript

💻 Use Cases

1. What do you want to use this for?
2. What shortcomings exist with current approaches?
3. What workarounds are you using in the meantime?

[jcalz]

Looks like a duplicate of #35501 (marked “closed” but not actually fixed) or one of the similar issues related to it.

[RyanCavanaugh]

The repro has a bunch of unbound identifiers, can you post something that's self-contained?