Today I Learned

A Hashrocket project

Viewing your test coverage in Elixir

Curious about test coverage in your Elixir application? Mix.Tasks.Test comes with a handy --cover option.

$ mix test --cover
...
Generating cover results ...

Percentage | Module
-----------|--------------------------
   ...
   100.00% | TilexWeb.PixelController
    75.00% | Mix.Tasks.Deploy
    30.00% | TilexWeb
   ...
-----------|--------------------------
    68.33% | Total

By default it uses a wrapper around OTPs built in cover, however that’s configurable. If you wanted to use something like excoveralls you could:

def project() do
  [
    ...
    test_coverage: [tool: ExCoveralls]
    ...
  ]
end

Other niceties, like color based thresholds, can be found in the docs

Looking for help? Elixir is quickly gaining momentum for web applications that need concurrency, performance, and the ability to connect to many different clients. The developers at Hashrocket are learning along with the rest of the development community that Elixir and Phoenix are viable Rails alternatives for the right application. Check out the source code for Today I Learned, written in Elixir, and contact us if you need help with your Elixir project.