Error after upgrade

I am getting following error after upgrading supertest to 6.1.1

Error: Invalid Chai property: stack. Did you mean "same"?
    at Object.proxyGetter [as get] (node_modules/chai/lib/chai/utils/proxify.js:75:17)
    at /home/circleci/project/node_modules/supertest/lib/test.js:81:20

What I can do about it?

[niftylettuce]

PR?

[janthoe]

Given the following example:

await request.get(`/api/v1/myResource`)
      .send()
      .expect(200)
      .expect(res => res.body.should.have.property('id'))

The error described above happens when the chai assertion succeeds. The reason is that the result of the arrow function is the chai assertion proxy. At supertest/lib/test.js#L80:

var err = assertFn(res);
if (err && err.stack) {
    ...
 }

Then using err.stack causes chai to throw the error Invalid Chai property: stack. Since err is expected to be an Error object, from SuperTest assertions or Chai assertions, the check should use instanceof instead:

var err = assertFn(res);
if (err instanceof Error && err.stack) {
    ...
 }