Go Testing
External
Internal
Overview
Go comes with a lightweight test framework that includes the go test command and the testing package. The tests live in *_test.go files, located in the package directory.
Packages
Test Types in Go
Unit Tests
Also see:
Writing a Unit Test
Write a module as shown here:
For each file containing behavior to test (a.go)
package a
func Reverse(s string) string {
rs := []rune(s)
var result []rune
for i := len(rs) - 1; i >= 0; i-- {
result = append(result, rs[i])
}
return string(result)
}
add a <file-name>_test.go test file. In this case a_test.go. These files are ignored by the compiler and only compiled and executed when go test is run. These files will be excluded from regular package builds. For more details on how go test command handles different files, see:
The test files should be part of the same package. If that is the case, the test has access to unexpected identifiers from the package being tested. It is also possible to declare the test files into a corresponding package with the suffix _test. In this case, the package being tested must be imported explicitly in the test. This is known as "black box" testing. Also see external test packages.
The test files should import testing.
Add individual tests, as functions starting with TestX.., where X... does not start with a lowercase letter, and taking an argument t *testing.T. The function name serves to identify the test routine. Within these functions, use Error, Fail or related methods to signal failure.
func TestX...(t *testing.T) {
...
t.Error("expected this: %q, got that: %q ", ...)
}
package a
import "testing"
func TestReverseEmptyString(t *testing.T) {
expected := ""
result := Reverse("")
if result != expected {
t.Errorf("expected %q, got %q", expected, result)
}
}
func TestReverseOneCharString(t *testing.T) {
expected := "a"
result := Reverse("a")
if result != expected {
t.Errorf("expected %q, got %q", expected, result)
}
}
func TestReverseTwoCharString(t *testing.T) {
expected := "ba"
result := Reverse("ab")
if result != expected {
t.Errorf("expected %q, got %q", expected, result)
}
}
From the module directory, run the tests:
go test
PASS ok example.com/a 0.116s
Integration Tests
We document implementation of integration tests in go. We use this definition of integration test:
We call them *_integration_test.go:
. └─ internal └── mypkg ├── mypkg.go ├── mypkg_test.go └── mypkg_integration_test.go
Code Coverage for Integration Tests
TO PROCESS: https://go.dev/blog/integration-test-coverage
Also see:
System Tests
Benchmarks
Process this: https://pkg.go.dev/testing#hdr-Benchmarks.
Fuzzing
Process this: https://pkg.go.dev/testing#hdr-Fuzzing.
Skipping
Process this: https://pkg.go.dev/testing#hdr-Skipping.
Subtests and Sub-benchmarks
Process this: https://pkg.go.dev/testing#hdr-Subtests_and_Sub_benchmarks.
Main
Process this: https://pkg.go.dev/testing#hdr-Main.
Mocks
Mock support: github.com/golang/mock/mockgen
TO DO
- Integrate see external test packages.
- Testing idiom "Introducing Go" page 96.
- Investigate gotest.tools module.
- Running go test immediately after cloning should succeed without any configuration or any running database. If a database is required, those are integration tests.
- https://about.sourcegraph.com/blog/go/advanced-testing-in-go