Add a code action to implement (overwritten) method from base class

Search Terms

implement, inherited, method

Suggestion

When implementing a method that is defined in a class's base class or in external type declarations, it would be helpful if we didn't have to type out the method signature that is already known to TypeScript.

Use Cases

Overwriting methods in inherited classes. Here's an example for implementing a custom winston transport.

TypeScript knows the method signature, but I have to type it out manually, potentially making a mistake along the way.

Examples

import * as Transport from "winston-transport";

export class SpyTransport extends Transport {
	log| // cursor here!
}

VSCode should offer a code action implement method "log" from base class "Transport". After invoking it, the code should look like this:

import * as Transport from "winston-transport";

export class SpyTransport extends Transport {
	public log(info: any, next: () => void): any {
		throw new Error("not implemented!");
	}
}

For reference, the type declarations look as follows:

declare class TransportStream extends stream.Writable {
  public format?: logform.Format;
  public level?: string;
  public silent?: boolean;
  public handleExceptions?: boolean;

  constructor(opts?: TransportStream.TransportStreamOptions);

  public log?(info: any, next: () => void): any;
  public logv?(info: any, next: () => void): any;
  public close?(): void;
}

Checklist

My suggestion meets these guidelines:

• 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, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

Start by locating the TypeScript or VSCode code-action entry point that handles inherited or unimplemented methods. Use the issue's TransportStream example and declaration as the behavioral reference, and consider the work complete when a code action offers the inherited method and generates its known signature and stub.