Allowing Unmatched Requests in OpenAI Mock API

[chihebnabil]

Hey

Hope that you are doing well

I'm currently working on an OpenAI mock API module using nock to simulate responses. However, I'm encountering an issue where I get ERR_NOCK_NO_MATCH for external API requests. I want to allow these external requests to pass through without dealing with this error.

Here's my current implementation:

const OPEN_AI_BASE_URL = 'https://api.openai.com';
const CHAT_COMPLETIONS_ENDPOINT = '/v1/chat/completions';
const IMAGE_GENERATIONS_ENDPOINT = '/v1/images/generations';

function mockOpenAIResponse(force = false) {
    var env = process.env.NODE_ENV || 'development';
    // Intercept the HTTP call and return the mock response
    if (env === 'development' || force) {
        nock(OPEN_AI_BASE_URL)
            .post(CHAT_COMPLETIONS_ENDPOINT)
            .reply(function (uri, requestBody) {
                return [200, getChatResponce(requestBody)];
            });

        nock(OPEN_AI_BASE_URL)
            .post(IMAGE_GENERATIONS_ENDPOINT)
            .reply(function (uri, requestBody) {
                return [200, getImageResponce(requestBody)];
            });

        // Mocking only the chat completion endpoint, not blocking other requests
        nock.emitter.on('no match', function (req) {
            nock.enableNetConnect(req);
        });
    }
}

I've tried different approaches like using nock.enableNetConnect() after defining mocks, but it doesn't seem to work. How can I modify my code to allow external API requests to pass through and avoid ERR_NOCK_NO_MATCH?

Any help or guidance would be greatly appreciated!

Thanks,

[mastermatt]

You're taking the wrong approach with your "no match" listener. By that point the net-connect check has already happened.
Instead of:

nock.emitter.on('no match', function (req) {
            nock.enableNetConnect(req);
        });

Try:

nock.enableNetConnect(host => host !== "api.openai.com");

This is essentially telling Nock to allow real network connections for any host other than OpenAIs.