v0.0.455 add proper json/bson marshalling to exerr [severity|type|category]

exerr/dataCategory.go

@@ -0,0 +1,89 @@
+package exerr
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/bson/bsoncodec"
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"reflect"
+)
+
+type ErrorCategory struct{ Category string }
+
+var (
+	CatWrap    = ErrorCategory{"Wrap"}    // The error is simply wrapping another error (e.g. when a grpc call returns an error)
+	CatSystem  = ErrorCategory{"System"}  // An internal system error (e.g. connection to db failed)
+	CatUser    = ErrorCategory{"User"}    // The user (the API caller) did something wrong (e.g. he has no permissions to do this)
+	CatForeign = ErrorCategory{"Foreign"} // A foreign error that some component threw (e.g. an unknown mongodb error), happens if we call Wrap(..) on an non-bmerror value
+)
+
+func (e *ErrorCategory) UnmarshalJSON(bytes []byte) error {
+	return json.Unmarshal(bytes, &e.Category)
+}
+
+func (e ErrorCategory) MarshalJSON() ([]byte, error) {
+	return json.Marshal(e.Category)
+}
+
+func (e *ErrorCategory) UnmarshalBSONValue(bt bsontype.Type, data []byte) error {
+	if bt == bson.TypeNull {
+		// we can't set nil in UnmarshalBSONValue (so we use default(struct))
+		// Use mongoext.CreateGoExtBsonRegistry if you need to unmarsh pointer values
+		// https://stackoverflow.com/questions/75167597
+		// https://jira.mongodb.org/browse/GODRIVER-2252
+		*e = ErrorCategory{}
+		return nil
+	}
+	if bt != bson.TypeString {
+		return errors.New(fmt.Sprintf("cannot unmarshal %v into String", bt))
+	}
+	var tt string
+	err := bson.RawValue{Type: bt, Value: data}.Unmarshal(&tt)
+	if err != nil {
+		return err
+	}
+	*e = ErrorCategory{tt}
+	return nil
+}
+
+func (e ErrorCategory) MarshalBSONValue() (bsontype.Type, []byte, error) {
+	return bson.MarshalValue(e.Category)
+}
+
+func (e ErrorCategory) DecodeValue(dc bsoncodec.DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if val.Kind() == reflect.Ptr && val.IsNil() {
+		if !val.CanSet() {
+			return errors.New("ValueUnmarshalerDecodeValue")
+		}
+		val.Set(reflect.New(val.Type().Elem()))
+	}
+
+	tp, src, err := bsonrw.Copier{}.CopyValueToBytes(vr)
+	if err != nil {
+		return err
+	}
+
+	if val.Kind() == reflect.Ptr && len(src) == 0 {
+		val.Set(reflect.Zero(val.Type()))
+		return nil
+	}
+
+	err = e.UnmarshalBSONValue(tp, src)
+	if err != nil {
+		return err
+	}
+
+	if val.Kind() == reflect.Ptr {
+		val.Set(reflect.ValueOf(&e))
+	} else {
+		val.Set(reflect.ValueOf(e))
+	}
+
+	return nil
+}
+
+//goland:noinspection GoUnusedGlobalVariable
+var AllCategories = []ErrorCategory{CatWrap, CatSystem, CatUser, CatForeign}