make originator unmarshalable (#77)

v1/types.go

@@ -521,6 +521,20 @@ func (o Originator) MarshalText() ([]byte, error) {
 	return nil, ErrInvalidOriginator
 }
 
+// UnmarshalText unmarshals originator from text to the value.
+func (o *Originator) UnmarshalText(text []byte) error {
+	switch string(text) {
+	case "customer":
+		*o = OriginatorCustomer
+		return nil
+	case "channel":
+		*o = OriginatorChannel
+		return nil
+	}
+
+	return ErrInvalidOriginator
+}
+
 type TransportErrorCode string
 
 const (

v1/types_test.go

@@ -98,6 +98,37 @@ func TestOriginator(t *testing.T) {
 	})
 
 	t.Run("MarshalJSON_Invalid", OriginatorMarshalJSONInvalid)
+
+	t.Run("UnmarshalText_Valid", func(t *testing.T) {
+		cases := []struct {
+			value Originator
+			text  []byte
+		}{
+			{1, []byte("customer")},
+			{2, []byte("channel")},
+		}
+		for _, c := range cases {
+			var o Originator
+			err := o.UnmarshalText(c.text)
+			assert.NoError(t, err)
+			assert.Equal(t, c.value, o)
+		}
+	})
+
+	t.Run("UnmarshalText_Invalid", func(t *testing.T) {
+		var o Originator
+		err := o.UnmarshalText([]byte{})
+		assert.Empty(t, o)
+		assert.Equal(t, err, ErrInvalidOriginator)
+	})
+
+	t.Run("UnmarshalJSON_Invalid", func(t *testing.T) {
+		var o Originator
+		err := json.Unmarshal([]byte("\"unknown\""), &o)
+		assert.Empty(t, o)
+		assert.Error(t, err)
+		assert.Equal(t, ErrInvalidOriginator, err)
+	})
 }
 
 func TestTransportErrorResponse(t *testing.T) {