Can't define an extension method on node's https.ClientRequest

Question

I'm getting an error TS2339: Property 'on' does not exist on type 'ClientRequest'. while I'm defining an extension method:

export {};

import {ClientRequest} from 'https';

declare module 'https' {
    class ClientRequest {
        loadData<T>(): Promise<T>;
    }
}

// // eslint-disable-next-line no-extend-native
ClientRequest.prototype.loadData = async function <T>(this: ClientRequest) {
    const result = new Promise<string>((resolve) => {
        let data = '';
        this.on('response', (res) => {
            res.on('data', (chunk) => {
                data += chunk;
            });

            res.on('end', () => {
                resolve(data);
            });
        });
    });
    return JSON.parse(await result) as T;
};

Answer 1

I was importing from the wrong module https instead of http , but TypeScript compiler didn't flag it as an error for some reason. Working code:

export {};

import {ClientRequest} from 'http';

// eslint-disable-next-line max-len
// Check how to import this module, so the extension property is accessible: https://www.typescriptlang.org/docs/handbook/release-notes/typescript-1-8.html#augmenting-globalmodule-scope-from-modules:~:text=%22./observable%22%3B-,import%20%22./map%22%3B,-let%20o%3A

declare module 'http' {
    export interface ClientRequest {
        plan: string;
        data<T>(): Promise<T>;
    }
}

// // eslint-disable-next-line no-extend-native
ClientRequest.prototype.data = async function <T>() {
    const result = new Promise<string>((resolve) => {
        let data = '';
        this.on('response', (res) => {
            res.on('data', (chunk) => {
                data += chunk;
            });

            res.on('end', () => {
                resolve(data);
            });
        });
    });
    return JSON.parse(await result) as T;
};

https://www.typescriptlang.org/docs/handbook/release-notes/typescript-1-8.html#augmenting-globalmodule-scope-from-modules