Increase Test Coverage

[bravetarget]

Problem or Request

The test coverage for the functions in this app is too low

Solution

Add more unit and integration tests to satisfy at least 50% coverage; ideally 80-100%

Additional context

Most of the tests being ran through health checks are just rendering passes

[michalmikolajczyk]

Do you think we should measure test coverage somehow?

[bravetarget]

@michalmikolajczyk we discussed adding a test coverage module in the past when we were closing similar issues in our other apps. however, i think we concluded it wasn't necessary? although, maybe since this is an open source repository, we could put more effort towards setting that up. i will add this as an optional task for this issue for now

edit: actually, just checked and jest has a built in way to check coverage. passing the argument --collect-coverage will output a report that shows percentage of individual files and all files, pretty nice!

and as for this stencil project we can just run something like:
stencil test --spec --coverage to get a report that includes coverage

[michalmikolajczyk]

that's awesome. We can automate by adding a check to the Travis CI file with a condition to pass only upon coverage > 50%