Refactor error handling

parser/errors.go

@@ -0,0 +1,24 @@
+package parser
+
+type ParseError struct {
+	Type    ParseErrorType
+	Message string
+	Raw     string
+}
+
+type ParseErrorType string
+
+const (
+	ErrInvalidPrefix     ParseErrorType = "invalid url prefix"
+	ErrInvalidStruct     ParseErrorType = "invalid struct"
+	ErrInvalidPort       ParseErrorType = "invalid port number"
+	ErrCannotParseParams ParseErrorType = "cannot parse query parameters"
+	ErrInvalidBase64     ParseErrorType = "invalid base64"
+)
+
+func (e *ParseError) Error() string {
+	if e.Message != "" {
+		return string(e.Type) + ": " + e.Message + " \"" + e.Raw + "\""
+	}
+	return string(e.Type)
+}