Please help debugging test failure and set headers error (Express, Mongoose, Node)

Hi All, all tests are passing up until the PUT section - the PUT updating works when I test it but something in the automated test is throwing errors about not being able to set headers after they are sent to the client.

I’ve thrown in a few console logs to see if I can work out what it’s doing but the errors are being thrown on all of the res.json()s in post and in put.

I’ve read every line of the error codes and can’t make head or tail sense of them … e.g. here:

node:5176) UnhandledPromiseRejectionWarning: Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at ServerResponse.setHeader (_http_outgoing.js:518:11)
    at ServerResponse.header (/home/runner/boilerplate-project-issuetracker/node_modules/express/lib/response.js:771:10)
    at ServerResponse.send (/home/runner/boilerplate-project-issuetracker/node_modules/express/lib/response.js:170:12)
    at ServerResponse.json (/home/runner/boilerplate-project-issuetracker/node_modules/express/lib/response.js:267:15)
    at /home/runner/boilerplate-project-issuetracker/routes/api.js:159:20
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)

Line 159 is one of the res.jsons

Been fiddling for a few hours with different logic steps but nothing seems to make
a) that test pass
or
b) the header errors go away

So I assume they are related!

Any help is hugely appreciated.

Edit: the failing test is:

When the PUT request sent to /api/issues/{projectname} does not include update fields, the return value is { error: 'no update field(s) sent', '_id': _id }. On any other error, the return value is { error: 'could not update', '_id': _id }.

Your project link(s)

solution: https://boilerplate-project-issuetracker.anilsiv.repl.co
https://repl.it/@anilsiv/boilerplate-project-issuetracker#routes/api.js

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36.

Challenge: Issue Tracker

Link to the challenge:

Edit: I’ve managed to surpress the errors by including “return” on the res.json() so that it breaks out of the code block - I expect that was the issue trying to res.json after it had already responded.

But I still can’t get that test to pass! I’ve tried to return the error in many different places and if I send over a valid ID with no fields it returns exactly the json requested from the test! :pensive:

It would really help if the test fail came back with an error message of some sort or if we could see the specific test case - is that possible?