elm-test | A unit testing framework for Elm | Unit Testing library

Rather than comparing entire chunks of Html msg together, you'll get better results using the Test.Html.Query module (and corresponding Test.Html.Selector and Test.Html.Event modules). This allows you to create more targeted tests (e.g. testing whether a certain element has certain text or a certain class, rather than testing the entirety of the HTML structure). And the test failures do provide much more context to help you debug.

I've built an example on Ellie, here's the basics of what a test might look like:

Thanks to @glennsl I found an solution. The solution is to specify where npm installs package globally. Since the runner that runs the action has no access to the /usr/local/lib npm can't install anything on a global level. The solution (as described here) is to create an folder as a "global" installation folder and configuring npm to use it. It is also necessary to add the new folder to the PATH environment variable.

So my yml file now looks like this