Nock fails to intercept requests in tests, but only in --coverage mode

Question

I recently upgraded some packages in a previously-working app and found that changes in Jest made a bunch of tests fail after the upgrade, but ONLY in --coverage mode.

All my Redux API action tests work fine when I run them without the --coverage flag. I am mocking all the API calls with nock in the tests and all the tests that are supposed to mock a successful API response are failing, because nock is failing to intercept the request.

Here's an example of a failing test and the code it's testing:

apiProfileActions.js

import { RSAA } from "redux-api-middleware";
const BASE_URL = process.env.REACT_APP_BASE_URL;

export const GET_PROFILE_REQUEST = "GET_PROFILE_REQUEST";
export const GET_PROFILE_SUCCESS = "GET_PROFILE_SUCCESS";
export const GET_PROFILE_FAILURE = "GET_PROFILE_FAILURE";


export function getProfile(token, userId) {
  return {
    [RSAA]: {
      endpoint: `${BASE_URL}/api/user/${userId}`,
      method: "GET",
      types: [
        GET_PROFILE_REQUEST,
        GET_PROFILE_SUCCESS,
        {
          type: GET_PROFILE_FAILURE,
          payload: (action, state, res) => {
            return res.json().then(data => {
              let message = "Sorry, something went wrong :(";
              if (data && data.message) {
                message = data.message;
              }
              return { message };
            });
          }
        }
      ],
      headers: { Authorization: `Bearer ${token}` }
    }
  };
}

apiProfileActions.test.js

/**
 * @jest-environment node
 */

import nock from "nock";
import { apiMiddleware } from "redux-api-middleware";
import configureMockStore from "redux-mock-store";
import * as actions from "../../store/actions/apiProfileActions";
import * as profileReducer from "../../store/reducers/profile";
const BASE_URL = process.env.REACT_APP_BASE_URL;
console.log(BASE_URL);

const createStore = configureMockStore([apiMiddleware]);
const store = createStore(profileReducer.initialState);
const id = "1234";
const token = "1651a5d6-c2f7-453f-bdc7-13888041add6";

describe("apiProfileActions", () => {
  describe("api actions", () => {
    afterEach(() => {
      nock.cleanAll();
      nock.enableNetConnect();
      // expect at least one expect in async code:
      expect.hasAssertions();
    });

    it("GET_PROFILE: Dispatches success action after successful GET", async () => {
      const response = {
        id,
        name: "Emma Goldman",
        avatar_url: "http://www.example.com/avatar.png"
      };

      nock(`${BASE_URL}`)
        .get(`/api/user/${response.id}`)
        .reply(200, response);

      const expectedResult = {
        payload: undefined,
        type: "GET_PROFILE_SUCCESS",
        meta: undefined
      };

      const result = await store.dispatch(
        actions.getProfile(token, response.id)
      );
      expect(result).toEqual(expectedResult);
    });
  });
});

and here's the console output for the failed test:

● apiProfileActions › api actions › GET_PROFILE: Dispatches success action after successful GET

    expect(received).toEqual(expected) // deep equality

    - Expected  - 2
    + Received  + 3

      Object {
    +   "error": true,
        "meta": undefined,
    -   "payload": undefined,
    -   "type": "GET_PROFILE_SUCCESS",
    +   "payload": [InternalError: [RSAA].ok function failed],
    +   "type": "GET_PROFILE_FAILURE",
      }

      111 |         actions.getProfile(token, response.id)
      112 |       );
    > 113 |       expect(result).toEqual(expectedResult);
          |                      ^
      114 |     });
      115 |
      116 |     it("GET_PROFILE: Dispatches failure action after failed GET", async () => {

      at Object.<anonymous> (src/__tests__/actions/apiProfileActions.test.js:113:22)

so all the tests that are supposed to mock successful api calls are returning failure responses instead, with error message [InternalError: [RSAA].ok function failed], because nock is failing to intercept the request and it's trying to hit the real API endpoint. Again these exact same tests are passing fine if the --coverage flag is off.

I have tried upgrading / downgrading nock and redux-api-middleware but this hasn't make any difference. Any ideas what might have changed to make nock stop working, but only when run in --coverage mode? Or any ideas where to start troubleshooting?