Unable to enableNetConnect for localhost (127.0.0.1)

[paulrobertlloyd]

I’ve set up a mock agent to intercept requests to https://api.github.com. However, my program makes calls to the application under test via 127.0.0.1.

Given I don’t want to mock these requests, I have passed 127.0.0.1 to enableNetConnect(), like so:

import { MockAgent, setGlobalDispatcher } from "undici";

const agent = new MockAgent();
agent.disableNetConnect();
agent.enableNetConnect("127.0.0.1");

export const githubAgent = () => {
  const client = agent.get("https://api.github.com");

  client.intercept({
    path: "/repos/user/repo/contents/foo.txt",
    method: "PUT"
  }).reply(201, {
    content: { path: "foo.txt" },
    commit: { message: "Message" },
  }).times(3);

  return client;
};

setGlobalDispatcher(githubAgent());

However, when running my tests, all paths are intercepted. For example, I need to call both http://127.0.0.1:65273/micropub and http://127.0.0.1:65273/token as part of my request chain (the port number is different each time), but the mock agent appears to interpret these as calls as belonging to the same origin in the mock agent, with the following error given:

Mock dispatch not matched for path '/micropub': subsequent request to origin https://api.github.com was not allowed (net.connect is not enabled for this origin)

Full error stack

TypeError: fetch failed
    at Object.processResponse (/Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:199:23)
    at /Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:928:38
    at node:internal/process/task_queues:140:7
    at AsyncResource.runInAsyncScope (node:async_hooks:203:9)
    at AsyncResource.runMicrotask (node:internal/process/task_queues:137:8)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5) {
  cause: MockNotMatchedError: Mock dispatch not matched for path '/micropub': subsequent request to origin https://api.github.com was not allowed (net.connect is not enabled for this origin)
      at MockPool.dispatch (/Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/mock/mock-utils.js:362:19)
      at /Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:1906:79
      at new Promise (<anonymous>)
      at dispatch (/Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:1906:12)
      at httpNetworkFetch (/Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:1718:61)
      at httpNetworkOrCacheFetch (/Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:1423:35)
      at httpFetch (/Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:1011:39)
      at schemeFetch (/Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:875:20)
      at /Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:570:22
      at mainFetch (/Users/paulrobertlloyd/Sites/indiekit/node_modules/undici/lib/fetch/index.js:620:7) {
    code: 'UND_MOCK_ERR_MOCK_NOT_MATCHED'
  }
}

Have I set up the mock agent incorrectly, or is this a bug?

[paulrobertlloyd]

Turns out enableNetConnect looks for an exact match for a given host, and doesn’t ignore the port. As a port is randomly assigned in each test, I used a regex instead:

agent.enableNetConnect(/(?:127\.0\.0\.1:\d{5})/);