Mocha timing out when test in Promise callback fails - mocha.js

Question

If I have the following module:
module.exports = kontinue => {
Promise.resolve({error:null})
.then(o => {
console.log('promise resolved');
// say something goes wrong here
if(true)
kontinue({error:'promise resolved but something else went wrong'});
else kontinue(o);
})
.catch(error => {
console.log('caught error');
kontinue({error:'promise rejected, or resolved but then continuation threw exception'})
});
};
And the following test:
const assert = require('assert').strict;
const target = require('./the_above_code.js');
it('should not timeout', (done) => {
target((sut) => {
console.log('continuation called');
assert.ok(false); // the test for sut.error === what I expected was failing
done();
});
});
It outputs:
promise resolved
continuation called
caught error
...
Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.
I realise this is because the .catch() is returning a new promise which is not resolving, but that's not what I really want during testing.
How do I test the object a promise resolves to, fail the test if necessary, have Mocha report that failure?
Perhaps there is somewhere else other than in the continuation (which never returns in the code that uses this module) that I can put the tests?
I'm sure monads can reduce the amount of boilerplate code here, but using them surely would violate Kernighan's maxim.