Add option to handle scream snake case enums.

README.md

@@ -53,7 +53,17 @@ See [contrib/tools/workflowcheck](contrib/tools/workflowcheck) for a tool to det
 ## Contributing
 We'd love your help in making the Temporal Go SDK great. Please review our [contribution guidelines](CONTRIBUTING.md).
 
-## Go build and run tags
+## Go SDK upgrading past v1.25.1
+
+Go SDK version v1.26.0 switched from using https://github.com/gogo/protobuf to https://github.com/golang/protobuf. While this migration is mostly internal there are a few user visible changes to be aware of:
+
+### Change in types
+
+* `time.Time` in proto structs will now be [timestamppb.Timestamp](https://pkg.go.dev/google.golang.org/protobuf@v1.31.0/types/known/timestamppb#section-documentation)
+* `time.Duration` will now be [durationpb.Duration](https://pkg.go.dev/google.golang.org/protobuf/types/known/durationpb)
+* V2-generated structs embed locks, so you cannot dereference them.
+
+### Invalid UTF-8
 
 Prior to SDK version v1.26.0 our protobuf code generator allowed invalid UTF-8 data to be stored as proto strings. This isn't actually allowed by the proto3 spec, so if you're using our SDK and think you may store arbitrary binary data in our strings you should set `-tags protolegacy` when building against our SDK.
 
@@ -67,5 +77,47 @@ If you see an error like `grpc: error unmarshalling request: string field contai
 
 If you're unsure then you should specify it anyways as there's no harm in doing so unless you relied on the protobuf compiler to ensure all strings were valid UTF-8.
 
+### Incompatible proto/json encoding
+
+Proto enums will, when formatted to JSON, now be in SCREAMING_SNAKE_CASE rather than PascalCase.
+    * If trying to deserialize old JSON with PascalCase to proto use [go.temporal.io/api/temporalproto]
+
+If users used Temporal proto types in their Workflows, such as for activity output, users may need to modify the default data converter to handle these payloads.
+``` go
+	converter.NewProtoJSONPayloadConverterWithOptions(converter.ProtoJSONPayloadConverterOptions{
+		LegacyTemporalProtoCompat: true,
+	}),
+```
+
+While upgrading from Go SDK version `< 1.26.0` to a version `>= 1.26.0` users may want to also bias towards using 
+proto binary to avoid any potential incompatibilities due to having clients serialize messages with incompatible `proto/json` format.
+
+On clients running Go SDK `< 1.26.0`
+``` go
+converter.NewCompositeDataConverter(
+		converter.NewNilPayloadConverter(),
+		converter.NewByteSlicePayloadConverter(),
+		converter.NewProtoPayloadConverter(),
+		converter.NewProtoJSONPayloadConverterWithOptions(),
+		converter.NewJSONPayloadConverter(),
+	)
+```
+
+On clients running Go SDK `>= 1.26.0`
+
+``` go
+converter.NewCompositeDataConverter(
+		converter.NewNilPayloadConverter(),
+		converter.NewByteSlicePayloadConverter(),
+		converter.NewProtoPayloadConverter(),
+		converter.NewProtoJSONPayloadConverterWithOptions(converter.ProtoJSONPayloadConverterOptions{
+			LegacyTemporalProtoCompat: true,
+		}),
+		converter.NewJSONPayloadConverter(),
+	)
+```
+
+Note: Payloads encoded with `proto/binary` will not be readable in the Temporal web UI. 
+
 ## License
 MIT License, please see [LICENSE](LICENSE) for details.

converter/proto_json_payload_converter.go

@@ -33,17 +33,19 @@ import (
 	gogojsonpb "github.com/gogo/protobuf/jsonpb"
 	gogoproto "github.com/gogo/protobuf/proto"
 	commonpb "go.temporal.io/api/common/v1"
+	"go.temporal.io/api/temporalproto"
 	"google.golang.org/protobuf/encoding/protojson"
 	"google.golang.org/protobuf/proto"
 )
 
 // ProtoJSONPayloadConverter converts proto objects to/from JSON.
 type ProtoJSONPayloadConverter struct {
-	gogoMarshaler         gogojsonpb.Marshaler
-	gogoUnmarshaler       gogojsonpb.Unmarshaler
-	protoMarshalOptions   protojson.MarshalOptions
-	protoUnmarshalOptions protojson.UnmarshalOptions
-	options               ProtoJSONPayloadConverterOptions
+	gogoMarshaler                 gogojsonpb.Marshaler
+	gogoUnmarshaler               gogojsonpb.Unmarshaler
+	protoMarshalOptions           protojson.MarshalOptions
+	protoUnmarshalOptions         protojson.UnmarshalOptions
+	temporalProtoUnmarshalOptions temporalproto.CustomJSONUnmarshalOptions
+	options                       ProtoJSONPayloadConverterOptions
 }
 
 // ProtoJSONPayloadConverterOptions represents options for `NewProtoJSONPayloadConverterWithOptions`.
@@ -64,6 +66,10 @@ type ProtoJSONPayloadConverterOptions struct {
 
 	// EmitUnpopulated specifies whether to emit unpopulated fields.
 	EmitUnpopulated bool
+
+	// LegacyTemporalProtoCompat will allow enums serialized as SCREAMING_SNAKE_CASE.
+	// Useful for backwards compatibility when migrating a proto message from gogoproto to standard protobuf.
+	LegacyTemporalProtoCompat bool
 }
 
 var (
@@ -73,10 +79,11 @@ var (
 // NewProtoJSONPayloadConverter creates new instance of `ProtoJSONPayloadConverter`.
 func NewProtoJSONPayloadConverter() *ProtoJSONPayloadConverter {
 	return &ProtoJSONPayloadConverter{
-		gogoMarshaler:         gogojsonpb.Marshaler{},
-		gogoUnmarshaler:       gogojsonpb.Unmarshaler{},
-		protoMarshalOptions:   protojson.MarshalOptions{},
-		protoUnmarshalOptions: protojson.UnmarshalOptions{},
+		gogoMarshaler:                 gogojsonpb.Marshaler{},
+		gogoUnmarshaler:               gogojsonpb.Unmarshaler{},
+		protoMarshalOptions:           protojson.MarshalOptions{},
+		protoUnmarshalOptions:         protojson.UnmarshalOptions{},
+		temporalProtoUnmarshalOptions: temporalproto.CustomJSONUnmarshalOptions{},
 	}
 }
 
@@ -99,6 +106,9 @@ func NewProtoJSONPayloadConverterWithOptions(options ProtoJSONPayloadConverterOp
 		protoUnmarshalOptions: protojson.UnmarshalOptions{
 			DiscardUnknown: options.AllowUnknownFields,
 		},
+		temporalProtoUnmarshalOptions: temporalproto.CustomJSONUnmarshalOptions{
+			DiscardUnknown: options.AllowUnknownFields,
+		},
 		options: options,
 	}
 }
@@ -193,7 +203,11 @@ func (c *ProtoJSONPayloadConverter) FromPayload(payload *commonpb.Payload, value
 
 	var err error
 	if isProtoMessage {
-		err = c.protoUnmarshalOptions.Unmarshal(payload.GetData(), protoMessage)
+		if c.options.LegacyTemporalProtoCompat {
+			err = c.temporalProtoUnmarshalOptions.Unmarshal(payload.GetData(), protoMessage)
+		} else {
+			err = c.protoUnmarshalOptions.Unmarshal(payload.GetData(), protoMessage)
+		}
 	} else if isGogoProtoMessage {
 		err = c.gogoUnmarshaler.Unmarshal(bytes.NewReader(payload.GetData()), gogoProtoMessage)
 	}