Adding test to main

cmd/installer/main.go

@@ -6,6 +6,10 @@ import (
 	"github.com/wavesoftware/serverless-installer/internal/cli"
 )
 
+var exit func(int) = func(exitcode int) {
+	os.Exit(exitcode)
+}
+
 func main() {
-	os.Exit(cli.NewRunner().Run())
+	exit(cli.NewRunner().Run())
 }

cmd/installer/main_test.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMain(t *testing.T) {
+	// given
+	oldExit := exit
+	oldArgs := os.Args
+	defer func() {
+		exit = oldExit
+		os.Args = oldArgs
+	}()
+	exitcode := ^int(0)
+	exit = func(received int) {
+		exitcode = received
+	}
+	os.Args = []string{"cmd", "--help"}
+
+	// when
+	main()
+
+	assert.Equal(t, 0, exitcode)
+}