Regression in node axios interception / resolver in 0.38

[tobiasr]

Describe the bug

Using a very simple setup results in intercepted requests not resolving in 0.38 . The same code works fine in 0.36.8 .

Environment

• msw: 0.38.0
• nodejs: 16.14.0
• npm: 8.3.1
• axios: ^0.26.0

To Reproduce

The following test works on msw 0.36.8 but not in 0.38.0, where the intercepted request doesn't resolve which is reported as a jest async timeout "thrown: "Exceeded timeout of 5000 ms for a test.".

import { rest } from 'msw';
import axios from 'axios';
import { setupServer } from 'msw/node';

const handlers = [
  rest.get('http://localhost/the_endpoint', (req, res, ctx) => {
    return res(ctx.status(200));
  }),
];

const server = setupServer(...handlers);

// Enable API mocking before tests.
beforeAll(() => server.listen());

// Reset any runtime request handlers we may add during the tests.
afterEach(() => server.resetHandlers());

// Disable API mocking after the tests are done.
afterAll(() => server.close());

test('mock axios call and return', () => {
  return axios.get('http://localhost/the_endpoint').then(() => {
    expect(true).toBe(true);
  });
})

Expected behavior

Expected behaviour is that the test above passes.

[kettanaito]

Hey, @tobiasr. Thanks for reporting this!

Unfortunately, I can't seem to reproduce the issue using your example above. I've also got some tests for axios.get() which are passing on the latest "interceptors" library.

Could you please create a reproduction repository where I can take a look at this? Thanks.

[textbook]

The example in the post also fails for me:

$  npm i msw@0.36  

added 4 packages, removed 1 package, changed 3 packages, and audited 1445 packages in 3s

157 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities
$ npm t dummy   

> impasse@0.9.0 test
> jest "dummy"

 PASS   server  server/dummy.test.js
  ✓ mock axios call and return (9 ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        0.264 s, estimated 6 s
Ran all test suites matching /dummy/i.
$ npm i msw@0.38

added 1 package, removed 4 packages, changed 3 packages, and audited 1442 packages in 1s

157 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities
$ npm t dummy

> impasse@0.9.0 test
> jest "dummy"

 FAIL   server  server/dummy.test.js (5.283 s)
  ✕ mock axios call and return (5001 ms)

  ● mock axios call and return

    thrown: "Exceeded timeout of 5000 ms for a test.
    Use jest.setTimeout(newTimeout) to increase the timeout value, if this is a long-running test."

      20 | afterAll(() => server.close());
      21 |
    > 22 | test("mock axios call and return", () => {
         | ^
      23 |      return axios.get("http://localhost/the_endpoint").then(() => {
      24 |              expect(true).toBe(true);
      25 |      });

      at Object.<anonymous> (server/dummy.test.js:22:1)
      at TestScheduler.scheduleTests (node_modules/@jest/core/build/TestScheduler.js:333:13)

Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 total
Snapshots:   0 total
Time:        5.307 s
Ran all test suites matching /dummy/i.

This is with Node 16.14.0/NPM 8.3.1 on macOS 12.2.1.

---

I don't know if it's helpful/related, but I was looking at issues with 0.38 because the upgrade from 0.36.8 caused a bunch of my existing tests to fail by timing out - in that case, as well as the timeout, I also see:

    TypeError: Cannot read properties of undefined (reading 'content-encoding')

      at node_modules/@mswjs/interceptors/src/interceptors/ClientRequest/utils/getIncomingMessageBody.ts:20:23
      at Object.getIncomingMessageBody (node_modules/@mswjs/interceptors/src/interceptors/ClientRequest/utils/getIncomingMessageBody.ts:11:10)
      at NodeClientRequest.<anonymous> (node_modules/@mswjs/interceptors/src/interceptors/ClientRequest/NodeClientRequest.ts:188:34)
      at step (node_modules/@mswjs/interceptors/lib/interceptors/ClientRequest/NodeClientRequest.js:48:23)
      at Object.next (node_modules/@mswjs/interceptors/lib/interceptors/ClientRequest/NodeClientRequest.js:29:53)
      at node_modules/@mswjs/interceptors/lib/interceptors/ClientRequest/NodeClientRequest.js:23:71
      at Object.<anonymous>.__awaiter (node_modules/@mswjs/interceptors/lib/interceptors/ClientRequest/NodeClientRequest.js:19:12)
      at NodeClientRequest.<anonymous> (node_modules/@mswjs/interceptors/src/interceptors/ClientRequest/NodeClientRequest.ts:187:68)

[kettanaito]

Oh, I see. This is an issue related to Node 16 moving the "headers" property of the IncomingMessage to its prototype. We're tracking it here: mswjs/interceptors#212. Once it's addressed on the interceptors' side it'll propagate to MSW.

[princefishthrower]

@kettanaito - that issue you mentioned (mswjs/interceptors#212) appears to be merged now into the interceptors library... is it safe to assume the fix has been incorporated in 0.38.2 ? Because I'm still seeing issues with axios.interceptors not being intercepted by msw...