Add golang implementation for karma tests (#919)

* Provide golang based karma step

cmd/karmaExecuteTests_test.go

@@ -0,0 +1,65 @@
+package cmd
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type mockRunner struct {
+	dir   []string
+	calls []execCall
+}
+
+type execCall struct {
+	exec   string
+	params []string
+}
+
+func (m *mockRunner) Dir(d string) {
+	m.dir = append(m.dir, d)
+}
+
+func (m *mockRunner) RunExecutable(e string, p ...string) error {
+	if e == "fail" {
+		return fmt.Errorf("error case")
+	}
+	exec := execCall{exec: e, params: p}
+	m.calls = append(m.calls, exec)
+	return nil
+}
+
+func TestRunKarma(t *testing.T) {
+	t.Run("success case", func(t *testing.T) {
+		opts := karmaExecuteTestsOptions{ModulePath: "./test", InstallCommand: "npm install test", RunCommand: "npm run test"}
+
+		e := mockRunner{}
+		err := runKarma(opts, &e)
+
+		assert.NoError(t, err, "error occured but no error expected")
+
+		assert.Equal(t, e.dir[0], "./test", "install command dir incorrect")
+		assert.Equal(t, e.calls[0], execCall{exec: "npm", params: []string{"install", "test"}}, "install command/params incorrect")
+
+		assert.Equal(t, e.dir[1], "./test", "run command dir incorrect")
+		assert.Equal(t, e.calls[1], execCall{exec: "npm", params: []string{"run", "test"}}, "run command/params incorrect")
+
+	})
+
+	t.Run("error case install command", func(t *testing.T) {
+		opts := karmaExecuteTestsOptions{ModulePath: "./test", InstallCommand: "fail install test", RunCommand: "npm run test"}
+
+		e := mockRunner{}
+		err := runKarma(opts, &e)
+		assert.Error(t, err, "error expected but none occcured")
+	})
+
+	t.Run("error case run command", func(t *testing.T) {
+		opts := karmaExecuteTestsOptions{ModulePath: "./test", InstallCommand: "npm install test", RunCommand: "fail run test"}
+
+		e := mockRunner{}
+		err := runKarma(opts, &e)
+		assert.Error(t, err, "error expected but none occcured")
+	})
+}