Go is a practical way to test Terraform modules with Terratest. Terratest uses Go’s testing package, so tests can also use other Go libraries. The tradeoff is that a team must learn a new language, but module tests can start as small scripts rather than full applications. section 9.3.1
To get a test running:
- Create a file in the project’s tests directory with a name ending in _test.go. Declare a package, import testing and any other needed packages, then write a test function. section 9.3.1
- In the tests directory, run go mod init with a module name, commonly a repository path. This creates go.mod. Then run go mod tidy to fetch dependencies and create go.sum. section 9.3.1
- Run the test and inspect its result. A passing run reports PASS; a failure identifies the test, source line and assertion mismatch. section 9.3.1
Listing 9.6 Example test in Go
package tests #1
import (
"testing" #2
"github.com/stretchr/testify/assert" #3
)
func TestExample(t *testing.T) { #4
assert.Equal(t, 1, 1) #5
}
This small test shows the package declaration, imports, a test function receiving *testing.T, and an assertion supplied by a third-party library. section 9.3.1
Go also appears when moving from Terraform configuration to provider development: install the Go tools first, and consider an IDE extension such as the VSCode Go extension. For an external-provider wrapper program, choose a language with its deployment environment in mind; the portability and maintenance tradeoffs differ from those of a small test. section 12.2 section 10.4.2
