Refactor unit tests to make use of github.com/stretchr/testify

[jannfis]

Is your task related to a problem? Please describe.

Currently, we are using a lot of code in the unit tests for evaluating outcomes in our unit tests, such as reflect.DeepEqual in if/else branch constructs to trigger t.Errorf() and the likes. This makes writing good unit tests quite a burden.

Describe the solution you'd like

Argo CD uses github.com/stretchr/testify for its unit tests, which is a quite flexible and convenient way to describe assertions on the expected test results, which also has nice output on failures.

We should refactor our unit tests to make use of this framework.

Describe alternatives you've considered

None really.

[iam-veeramalla]

Found a nice and well elaborated comparisons of the most popular options: https://bmuschko.com/blog/go-testing-frameworks/

Can we also consider BDD testing options like ginkgo/gomega ? @jannfis

[jannfis]

Thanks for that link, @iam-veeramalla, it's a great summary.

And sure, I think it's a great idea to explore possible other options. I'm only a little opinionated on testify, since its used in other Argo CD sub-projects already and is quite lightweight and very easy to use. But maybe we can pick up a set of certain existing unit tests and try to model them in various frameworks, to see how it will fit. WDYT?

[iam-veeramalla]

@jannfis sure .. That would be great !!

[jannfis]

First chunk of migration to stretchr/testify can be seen in https://github.com/argoproj-labs/argocd-operator/pull/437