How to fix TS nock library not intercepting my API call?

Question

I am using node 18 in my Typescript code and nock library https://www.npmjs.com/package/nock for tests.

I have a simple class which makes fetch call to one endpoint and want to test it by mocking the response.

My simplified code is

MagicClient.ts

type Config = {
    baseUrl: string;
};

export default class MagicClient {
    // eslint-disable-next-line no-useless-constructor
    constructor(private readonly config: Config) {}

    public async doMagic(): Promise<Object> {
        const response = await fetch(`${this.config.baseUrl}/do-magic`, {
            method: 'POST',
            headers: {
                Accept: 'application/json',
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({ magic: true }),
        });


        return JSON.parse(await response.text());
    }
}

My test code is

MagicClient.test.ts

import nock from 'nock';

import MagicClient from '../../../src/MagicClient';

describe(MagicClient.name, () => {
    const client = new MagicClient({
        baseUrl: process.env.MAGIC_BASE_URL, 
    });

    beforeEach(() => {
        jest.resetAllMocks();

        nock.cleanAll();
        nock.disableNetConnect();
        nock.enableNetConnect('127.0.0.1');
    });

    afterEach(() => {
        expect(nock.isDone()).toBeTruthy();
    });

    const mockedResponse = {
         success: true,
         magic: 'abc',
    };
    it('calls do magic', () => {
        nock(process.env.MAGIC_BASE_URL)
            .post('/do-magic', { magic: true })
            .reply(200, mockedResponse);

        expect(
            client.doMagic(),
        ).toEqual(mockedResponse);
    });
});

Result is:

Real endpoint is being called! and nock does nothing. I can fully confirm this because I get response from real api endpoint... instead of seeing my mock response

My environment:

node v18.16.0
"jest": "^29.2.0",
"nock": "^13.4.0",

My thoughts:

I think nock.disableNetConnect(); is not working sometimes... as the call is clearly going through the real endpoint in the internet. I have setup the test env process.env.MAGIC_BASE_URL to match a real endpoint, no localhost nothing is a public rest http endpoint and call goes through..

I have another doubt and it might be that nock does not intercept the native fetch...

Any idea why this is not working and how to fix ?

I have other code using nock exactly in the same way that works fine so it is mind blowing.

Answer 1

After deep debugging I figured out nock does not support native fetch

I confirmed that this is the issue because found it reported as well

https://github.com/nock/nock/issues/2397

Solution

I just imported for the time being import fetch from 'node-fetch'; in top of the file and nock worked