02 January 2021
A build tag or a build constraint as described in the build package documentation, is a line comment that begins // +build that lists the conditions under which a file should be included in the package.
You can provide build constraints for one file. The tags can then be passed to the go build command, when building the package, like so
$ go build -tags <tags>
$ go test -tags=integration
Also This will allow us to separate test cases by separating them in different files and then giving each file a special build tag. here is an example:
// main.go file
package main
func main() {
//
}
// Sum ...
func Sum(ar []int) int {
result := 0
for _, v := range ar {
result += v
}
return result
}
// main_unit_test.go file
// +build unit
package main
import (
"testing"
"github.com/franela/goblin"
)
// TestUnitSum test cases
func TestUnitSum(t *testing.T) {
g := goblin.Goblin(t)
g.Describe("#SumFunc", func() {
g.It("It should satisfy all provided test cases", func() {
var tests = []struct {
input []int
wantResult int
}{
{[]int{1, 2, 3, 4, 5}, 15},
{[]int{3, 4, 5}, 12},
{[]int{36, 98, 63, 3628, 2863, 27392, 883929}, 918009},
{[]int{36, 21, 63, 12, 56, 90, 32}, 310},
{[]int{123, 283, 345, 544, 332, 4455, 1233}, 7315},
}
for _, tt := range tests {
g.Assert(Sum(tt.input)).Equal(tt.wantResult)
}
})
})
}
// BenchmarkUnitSum benchmark
func BenchmarkUnitSum(b *testing.B) {
var input []int
for n := 0; n < b.N; n++ {
input = append(input, n)
}
b.Logf("[Unit] Sum function input length %v \n", len(input))
Sum(input)
}
// main_integration_test.go file
// +build integration
package main
import (
"testing"
"github.com/franela/goblin"
)
// TestIntegrationSum test cases
func TestIntegrationSum(t *testing.T) {
// Skip if -short flag exist
if testing.Short() {
t.Skip("skipping test in short mode.")
}
g := goblin.Goblin(t)
g.Describe("#SumFunc", func() {
g.It("It should satisfy all provided test cases", func() {
var tests = []struct {
input []int
wantResult int
}{
{[]int{1, 2, 3, 4, 5}, 15},
{[]int{3, 4, 5}, 12},
{[]int{36, 98, 63, 3628, 2863, 27392, 883929}, 918009},
{[]int{36, 21, 63, 12, 56, 90, 32}, 310},
{[]int{123, 283, 345, 544, 332, 4455, 1233}, 7315},
}
for _, tt := range tests {
g.Assert(Sum(tt.input)).Equal(tt.wantResult)
}
})
})
}
// BenchmarkIntegrationSum benchmark
func BenchmarkIntegrationSum(b *testing.B) {
// Skip if -short flag exist
if testing.Short() {
b.Skip("skipping test in short mode.")
}
var input []int
for n := 0; n < b.N; n++ {
input = append(input, n)
}
b.Logf("[Integration] Sum function input length %v \n", len(input))
Sum(input)
}
$ go test -tags=unit -bench=. -benchmem -v -cover ./...
$ go test -tags=integration -bench=. -benchmem -v -cover ./...
Another way of separating our tests is the -run flag. This flag takes a regexp as a value, which then the test command uses in order for it to run only the tests whose name matches against it. so we can use it with the above example after removing the build flag
// main.go file
package main
func main() {
//
}
// Sum ...
func Sum(ar []int) int {
result := 0
for _, v := range ar {
result += v
}
return result
}
// main_unit_test.go file
package main
import (
"testing"
"github.com/franela/goblin"
)
// TestUnitSum test cases
func TestUnitSum(t *testing.T) {
g := goblin.Goblin(t)
g.Describe("#SumFunc", func() {
g.It("It should satisfy all provided test cases", func() {
var tests = []struct {
input []int
wantResult int
}{
{[]int{1, 2, 3, 4, 5}, 15},
{[]int{3, 4, 5}, 12},
{[]int{36, 98, 63, 3628, 2863, 27392, 883929}, 918009},
{[]int{36, 21, 63, 12, 56, 90, 32}, 310},
{[]int{123, 283, 345, 544, 332, 4455, 1233}, 7315},
}
for _, tt := range tests {
g.Assert(Sum(tt.input)).Equal(tt.wantResult)
}
})
})
}
// BenchmarkUnitSum benchmark
func BenchmarkUnitSum(b *testing.B) {
var input []int
for n := 0; n < b.N; n++ {
input = append(input, n)
}
b.Logf("[Unit] Sum function input length %v \n", len(input))
Sum(input)
}
// main_integration_test.go file
package main
import (
"testing"
"github.com/franela/goblin"
)
// TestIntegrationSum test cases
func TestIntegrationSum(t *testing.T) {
// Skip if -short flag exist
if testing.Short() {
t.Skip("skipping test in short mode.")
}
g := goblin.Goblin(t)
g.Describe("#SumFunc", func() {
g.It("It should satisfy all provided test cases", func() {
var tests = []struct {
input []int
wantResult int
}{
{[]int{1, 2, 3, 4, 5}, 15},
{[]int{3, 4, 5}, 12},
{[]int{36, 98, 63, 3628, 2863, 27392, 883929}, 918009},
{[]int{36, 21, 63, 12, 56, 90, 32}, 310},
{[]int{123, 283, 345, 544, 332, 4455, 1233}, 7315},
}
for _, tt := range tests {
g.Assert(Sum(tt.input)).Equal(tt.wantResult)
}
})
})
}
// BenchmarkIntegrationSum benchmark
func BenchmarkIntegrationSum(b *testing.B) {
// Skip if -short flag exist
if testing.Short() {
b.Skip("skipping test in short mode.")
}
var input []int
for n := 0; n < b.N; n++ {
input = append(input, n)
}
b.Logf("[Integration] Sum function input length %v \n", len(input))
Sum(input)
}
$ go test -run=Integration -bench=. -benchmem -v -cover ./...
$ go test -run=Unit -bench=. -benchmem -v -cover ./...