feat: support client headers request

currently support client custom headers and convert to metadata.MD for grpc.

jrpc/server.go

@@ -3,6 +3,9 @@ package jrpc
 import (
 	"context"
 	"encoding/json"
+	"github.com/creachadair/jrpc2"
+	"google.golang.org/grpc/metadata"
+	"io"
 	"net"
 	"net/http"
 	"time"
@@ -22,6 +25,11 @@ type Server struct {
 	handler http.Handler
 }
 
+type paramsAndHeaders struct {
+	Headers metadata.MD     `json:"headers,omitempty"`
+	Params  json.RawMessage `json:"params"`
+}
+
 // NewServer create json rpc server
 func NewServer() *Server {
 	sv := new(Server)
@@ -58,9 +66,43 @@ func (s *Server) RegisterServices(svs ...Service) {
 			hd[m] = handler.New(h)
 		}
 	}
-	s.handler = jhttp.NewBridge(hd, nil)
+	s.handler = jhttp.NewBridge(hd, &jhttp.BridgeOptions{
+		ParseRequest: func(req *http.Request) ([]*jrpc2.ParsedRequest, error) {
+			body, err := io.ReadAll(req.Body)
+			if err != nil {
+				return nil, err
+			}
+			prs, err := jrpc2.ParseRequests(body)
+			if err != nil {
+				return nil, err
+			}
+
+			// Decorate the incoming request parameters with the headers.
+			for _, pr := range prs {
+				w, err := json.Marshal(paramsAndHeaders{
+					Headers: headersToMetadata(req),
+					Params:  pr.Params,
+				})
+				if err != nil {
+					return nil, err
+				}
+				pr.Params = w
+			}
+			return prs, nil
+		},
+	})
 }
 
 func (s *Server) httpHandler(w http.ResponseWriter, r *http.Request) {
 	s.handler.ServeHTTP(w, r)
 }
+
+func headersToMetadata(r *http.Request) metadata.MD {
+	headersMap := make(map[string]string)
+	for key, values := range r.Header {
+		if len(values) > 0 {
+			headersMap[key] = values[0]
+		}
+	}
+	return metadata.New(headersMap)
+}

jrpc/server_test.go

@@ -21,10 +21,16 @@ func (ms *MockService) Methods() map[string]method {
 }
 
 func (ms *MockService) testMethod(ctx context.Context, message json.RawMessage) (any, error) {
+	var ph paramsAndHeaders
+	if err := json.Unmarshal(message, &ph); err != nil {
+		return nil, err
+	}
+
 	var params map[string]string
-	if err := json.Unmarshal(message, &params); err != nil {
+	if err := json.Unmarshal(ph.Params, &params); err != nil {
 		return nil, err
 	}
+
 	return map[string]string{"response": "Hello " + params["name"]}, nil
 }
 
@@ -34,15 +40,19 @@ func TestServer(t *testing.T) {
 	mockService := &MockService{}
 	server.RegisterServices(mockService)
 
-	// Create a listener for the server
 	listener, err := net.Listen("tcp", "127.0.0.1:0")
 	assert.NoError(t, err, "Failed to create listener")
 
+	serverStarted := make(chan struct{})
+
 	go func() {
-		err = server.Serve(listener)
+		close(serverStarted)
+		err := server.Serve(listener)
 		assert.Error(t, err, "Server failed to serve")
 	}()
 
+	<-serverStarted
+
 	requestBody, err := json.Marshal(map[string]any{
 		"jsonrpc": "2.0",
 		"id":      "1",