The repository demonstrates how to use the Ruby MiniTest test framework to unit test Helm Charts.
All the boilerplate code with convenience helpers and wrapper is located in test/test_helper.rb.
test/charts/web_spec.rb contains the example unit tests for the Helm Chart chart/web.
We use helm template and jq to run the test, so must make sure you have Helm installed and the JQ development libraries are installed on your workstation.
A couple more details are explain in my blog post Helm Chart Unit Testing