Axios v0.32 compatibility: crash when `config.headers` has null prototype + matcher misses for null-prototype params

[anzhelikakovalchuk]

Hi maintainers 👋

We’re seeing compatibility issues with axios-mock-adapter@2.1.0 when used with axios@0.32.0.

Environment

• axios-mock-adapter: 2.1.0
• axios: 0.32.0

Problem

1) Crash in handle_request.js

handle_request.js assumes config.headers.constructor.name exists:

(config.headers && config.headers.constructor.name === "AxiosHeaders")

With axios 0.32, config.headers can be a null-prototype object, so config.headers.constructor is undefined, causing:
TypeError: Cannot read properties of undefined (reading 'name')

2) Matcher misses (404/no match) for params objects

Some request params objects from axios 0.32 are null-prototype objects.

Deep equality against plain object matcher config (e.g. onGet(url, { params: { include: 'x' } })) can fail even when values are equivalent, causing unexpected no-match/404 behavior.

Minimal repro (crash)

const axios = require('axios');
const MockAdapter = require('axios-mock-adapter');

const mock = new MockAdapter(axios);
mock.onGet('/x').reply(200, { ok: true });

axios.get('/x')
  .then(r => console.log(r.status))
  .catch(e => console.error(e.message));

Observed: Cannot read properties of undefined (reading 'name')
Expected: 200 response from mock adapter.

Suggested fix:
Guard constructor access in handle_request.js:

config.headers &&
config.headers.constructor &&
config.headers.constructor.name === "AxiosHeaders"

[joelwatson]

Subscribing...this breaks for my projects as well :(