Unit Testing

Go is a statically typed language, which makes it easy to write unit tests. The Go standard library provides a testing package that allows you to write tests for your code. The testing package provides a framework for writing tests, and the go test command runs the tests. Other than that there are a lot of libraries and tools available to make testing easier.

Testify - A toolkit with common assertions and mocks that plays nicely with the standard library.
Ginkgo - A BDD-style testing framework for Go.
Gomega - A matcher/assertion library for Ginkgo.
GoDog - A Behavior-Driven Development framework for Go which uses Gherkin.

In oCIS we generally use Ginkgo framework for testing. To keep things consistent, we would encourage you to use the same. In some cases, where you feel the need for a more verbose or more “code oriented” approach, you can also use the testing package from the standard library without ginkgo.

1 Ginkgo

Using a framework like Ginkgo brings many advantages.

Pros

Provides a BDD-style syntax which makes it easier to write reusable and understandable tests
Together with Gomega it provides a powerful and expressive framework with assertions in a natural language
Natural Language Format empowers testing in a way that resembles user interactions with the system
In the context of microservices it is particularly well suited to test individual services and the interactions between them
Offers support for asynchronous testing which makes it easier to test code that involves concurrency
Nested and structured containers and setup capabilities make it easy to organize tests and adhere to the DRY principle
Provides helpful error messages to identify and fix issues
Very usable for Test Driven Development following the “Red, Green, Cleanup, Repeat” workflow.

Cons

Sometimes it can be difficult to get started with
Asynchronous behaviour brings more complexity to tests.
Not compatible with broadly known testify package

Example

As you can see, Ginkgo and Gomega together provide the foundation to write understandable and maintainable tests which can mimic user interaction and the interactions between microservices.

Describe("Public Share Provider", func() {
  Context("When the user has no share permission", func() {
    BeforeEach(func() {
        // downgrade user permissions to have no share permission
        resourcePermissions.AddGrant = false
    })
    It("should return grpc invalid argument", func() {
        req := &link.CreatePublicShareRequest{}

        res, err := provider.CreatePublicShare(ctx, req)
        Expect(err).ToNot(HaveOccurred())
        Expect(res.GetStatus().GetCode()).To(Equal(rpc.Code_CODE_INVALID_ARGUMENT))
        Expect(res.GetStatus().GetMessage()).To(Equal("no share permission"))
    })
})

How to use it in oCIS

2 Testing Package

For smaller straight-forward tests of some packages it might feel more natural to use the testing package that comes with the go standard library.

Unit Testing

1 Ginkgo

Pros

Cons

Example

How to use it in oCIS

2 Testing Package

Pros

Cons

How to use it in ocis