As with many of the basic and intermediate development and deployment requirements you may have, Go comes with a built-in application for handling unit tests.
The basic premise behind testing is that you create your package and then create a testing package to run against the initial application. The following is a very basic example:
mathematics.go
package mathematics
func Square(x int) int {
return x * 3
}
mathematics_test.go
package mathematics
import
(
"testing"
)
func Test_Square_1(t *testing.T) {
if Square(2) != 4 {
t.Error("Square function failed one test")
}
}A simple Go test in that subdirectory will give you the response you're looking for. While this was admittedly simple—and purposefully flawed—you can probably see how easy it is to break apart your code and test it incrementally. This is enough to do very basic unit tests out of the box.
Correcting this would then be fairly simple—the same test would pass on the following code:
func Square(x int) int {
return x * x
}The testing package is somewhat limited; however, as it provides basic pass/fails without the ability to do assertions. There are two third-party packages that can step in and help in this regard, and we'll explore them in the following sections.
GoCheck extends the basic testing package primarily by augmenting it with assertions and verifications. You'll also get some basic benchmarking utility out of it that works a little more fundamentally than anything you'd need to engineer using Go.
Tip
For more details on GoCheck visit http://labix.org/gocheck and install it using go get gopkg.in/check.v1.
Unlike GoCheck, Ginkgo (and its dependency Gomega) takes a different approach to testing, utilizing the behavior-driven development (BDD) model. Behavior-driven development is a general model for making sure your application does what it should at every step, and Ginkgo formalizes that into some easily parseable properties.
BDD tends to complement test-driven development (for example, unit testing) rather than replacement. It seeks to answer a few critical questions about the way people (or other systems) will interact with your application. In that sense, we'll generally describe a process and what we expect from that process in fairly human-friendly terms. The following is a short snippet of such an example:
Describe("receive new remote TCP connection", func() {
Context("user enters a number", func() {
It("should be an integer", func() {
})
})
})This allows testing to be as granular as unit testing, but also expands the way we handle application usage in verbose and explicit behaviors.
If BDD is something you or your organization is interested in, this is a fantastic, mature package for implementing deeper unit testing.
Tip
For more information on Ginkgo go to https://github.com/onsi/ginkgo and install it using go get github.com/onsi/ginkgo/ginkgo.
For more information on dependency, refer to go get github.com/onsi/gomega.