IncomingMessage should implement ReadableStream

[andersk]

(Feel free to redirect me if this bug should be reported elsewhere.)

The definition of IncomingMessage (generated from https://github.com/electron/electron/releases/download/v9.1.0/electron-api.json) fails to reflect the documentation’s guarantee that “IncomingMessage implements the Readable Stream interface”:

  class IncomingMessage extends NodeEventEmitter {

    // Docs: http://electronjs.org/docs/api/incoming-message

    /**
     * Emitted when a request has been canceled during an ongoing HTTP transaction.
     */
    on(event: 'aborted', listener: Function): this;
    // …
    // more events
    // …
    removeListener(event: 'error', listener: Function): this;
    headers: Record<string, string[]>;
    httpVersion: string;
    httpVersionMajor: number;
    httpVersionMinor: number;
    statusCode: number;
    statusMessage: string;
  }

So working code like this fails to type check:

import { app, net } from "electron";
import getStream from "get-stream";

app.on("ready", () => {
  const request = net.request({url: "https://example.com"});
  request.on("response", async response => {
    if (true) {
      // error TS2345: Argument of type 'IncomingMessage' is not assignable to parameter of type 'Stream'.
      console.log(await getStream(response));
    } else {
      // error TS2495: Type 'IncomingMessage' is not an array type or a string type.
      for await (const chunk of response) {
        console.log(chunk.toString());
      }
    }
  });
  request.end();
});

[MarshallOfSound]

Refs: https://github.com/electron/electron/issues/22730

[andersk]

Still an issue in Electron 21.1.0, 22.0.0-alpha.3, and 23.0.0-nightly.20221007.

[efattal]

The confusing part is that the docs stands that "IncomingMessage implements the Readable Stream...". So we can expect that the stream is usable like any other ones.