add command test

command_test.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+
+func TestGetFn(t *testing.T) {
+
+	c := newCommand()
+
+	c.define("sample", func() {})
+
+	f, err := c.getFn("sample")
+	if err != nil {
+		t.Error(err)
+	}
+
+	assert.NotNil(t, f)
+
+	f, err = c.getFn("x")
+	assert.Error(t, err)
+}