Why is my Node.js code not covered correctly?

I am trying to learn testing and code coverage in Node.js but I keep running into troubles.

I use Mocha for the tests and istanbul (nyc) for the coverage.

I tried to write a simple web server with express that sends a response on get, the response being Hello, World.

code and test

Now to test my server I check two things

• Server sends back 200 (everything is ok)
• Server response when get is Hello, World

The test seems to work fine, if I change the assertions they break and everything seems to work fine, however I cant get the coverage to work properly, it tells me the functions are not covered and I really don't understand what I am doing wrong.

I run nyc mocha index.spec.js to generate the coverage and here it is :

coverage report

See the functions that I thought I tested appear to not be covered and I can't tell if it has to do with my code being asynchronous or my test being plain wrong. I would really appreciate any help on the matter.

via Kevin