Mocha Chai HTTP post request not working

This does go against database design. Look for descriptions of normalization and relational algebra. It is bad mainly because of the comment you have made "duplicating the rows but this could be error prone, plus making a small change would have to be done on several rows, again buggy."

The idea of relational databases is to act on sets of data and find things by matching on primary and foreign keys and absolutely not to use or think of pointers at all.

If you have common data for each product, then create a product table

create table product (
  product_id int,
  field1 ...,
  field2 ...,
  field3
)
with primary key on product_id

The main table would have fields id, color_id and product_id

if product table looks like

product_id | field1   | field2   | field3  
-----------------------------------------------
1          | value1   | value2   | value3  
2          | valueA   | valueB   | valueC  
3          | valueX   | valueY   | valueZ   

The main table would look like

id | product_id | color_id
--------------------------------
1  | 1          | blue
2  | 1          | red
3  | 1          | green  
4  | 2          | orange
5  | 2          | brown
6  | 3          | pink
7  | 3          | yellow

The issue is caused by this:

.catch((error) => {
  assert.isNotOk(error,'Promise error');
  done();
});

If the assertion fails, it will throw an error. This error will cause done() never to get called, because the code errored out before it. That's what causes the timeout.

The "Unhandled promise rejection" is also caused by the failed assertion, because if an error is thrown in a catch() handler, and there isn't a subsequent catch() handler, the error will get swallowed (as explained in this article). The UnhandledPromiseRejectionWarning warning is alerting you to this fact.

In general, if you want to test promise-based code in Mocha, you should rely on the fact that Mocha itself can handle promises already. You shouldn't use done(), but instead, return a promise from your test. Mocha will then catch any errors itself.

Like this:

it('should transition with the correct event', () => {
  ...
  return new Promise((resolve, reject) => {
    ...
  }).then((state) => {
    assert(state.action === 'DONE', 'should change state');
  })
  .catch((error) => {
    assert.isNotOk(error,'Promise error');
  });
});