diff --git a/validator_test.go b/validator_test.go
new file mode 100644
index 0000000..0b3e2fd
--- /dev/null
+++ b/validator_test.go
@@ -0,0 +1,41 @@
+package validator
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_msg(t *testing.T) {
+	tests := []struct {
+		name        string
+		method      string
+		msg         string
+		expectedMsg string
+	}{
+		{
+			name:        "test not exists method will result a panic",
+			method:      "qwert",
+			msg:         "",
+			expectedMsg: "method message does not exist",
+		},
+		{
+			name:        "test empty string method will result a panic",
+			method:      "",
+			msg:         "",
+			expectedMsg: "method message does not exist",
+		},
+		{
+			name:        "test empty space string method will result a panic",
+			method:      " ",
+			msg:         "",
+			expectedMsg: "method message does not exist",
+		},
+	}
+
+	v := New()
+
+	for _, test := range tests {
+		assert.PanicsWithError(t, test.expectedMsg, func() { v.msg(test.method, test.msg) })
+	}
+}