.github/dependabot.yml

@@ -1,10 +0,0 @@
-version: 2
-updates:
-  - package-ecosystem: "github-actions"
-    directory: "/"
-    schedule:
-      interval: "monthly"
-    groups:
-      github-actions:
-        patterns:
-          - "*"

.github/workflows/ci.yml

@@ -4,10 +4,6 @@ on:
   push:
     branches:
       - master
-
-permissions:
-  contents: read
-
 jobs:
   test:
     strategy:
@@ -18,9 +14,9 @@ jobs:
     name: Go ${{ matrix.go }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v3
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@v2
         with:
           go-version: ${{ matrix.go }}
         id: go

.github/workflows/lsif.yml

@@ -0,0 +1,13 @@
+name: LSIF
+on:
+  - push
+jobs:
+  lsif-go:
+    runs-on: ubuntu-latest
+    container: sourcegraph/lsif-go
+    steps:
+      - uses: actions/checkout@v1
+      - name: Generate LSIF data
+        run: lsif-go
+      - name: Upload LSIF data
+        run: src lsif upload -github-token=${{ secrets.GITHUB_TOKEN }}

.github/workflows/scip.yml

@@ -1,20 +0,0 @@
-name: SCIP
-'on':
-  - push
-permissions:
-  contents: read
-jobs:
-  scip-go:
-    runs-on: ubuntu-latest
-    container: sourcegraph/scip-go
-    steps:
-      - uses: actions/checkout@v6
-      - name: Get src-cli
-        run: curl -L https://sourcegraph.com/.api/src-cli/src_linux_amd64 -o /usr/local/bin/src;
-          chmod +x /usr/local/bin/src
-      - name: Set directory to safe for git
-        run: git config --global --add safe.directory $GITHUB_WORKSPACE
-      - name: Generate SCIP data
-        run: scip-go
-      - name: Upload SCIP data
-        run: src code-intel upload -github-token=${{ secrets.GITHUB_TOKEN }}

README.md

@@ -3,8 +3,9 @@
 
 Package jsonrpc2 provides a [Go](https://golang.org) implementation of [JSON-RPC 2.0](http://www.jsonrpc.org/specification).
 
-* [Documentation](https://pkg.go.dev/github.com/sourcegraph/jsonrpc2)
-* [Open the code in Sourcegraph](https://sourcegraph.com/github.com/sourcegraph/jsonrpc2)
+This package is **experimental** until further notice.
+
+[**Open the code in Sourcegraph**](https://sourcegraph.com/github.com/sourcegraph/jsonrpc2)
 
 ## Known issues
 

SECURITY.md

@@ -1,12 +0,0 @@
-# Security Policy
-
-## Supported Versions
-
-Security updates are applied only to the latest release.
-
-## Reporting a Vulnerability
-
-If you have discovered a security vulnerability in this project, please report it privately. **Do not disclose it as a public issue.** This gives us time to work with you to evaluate and fix the issue before public exposure, reducing the chance that the exploit will be used before a patch is released.
-
-Please disclose it privately via email to security@sourcegraph.com. We will work with you to understand and resolve the issue promptly.
-

conn.go

@@ -27,7 +27,6 @@ type Conn struct {
 
 	sending sync.Mutex
 
-	cancelCtx  context.CancelFunc
 	disconnect chan struct{}
 
 	logger Logger
@@ -44,19 +43,13 @@ var _ JSONRPC2 = (*Conn)(nil)
 // JSON-RPC protocol is symmetric, so a Conn runs on both ends of a
 // client-server connection.
 //
-// NewConn consumes stream, so you should call Close on the returned
-// Conn not on the given stream or its underlying connection.
-//
-// Conn is closed when the given context's Done channel is closed.
+// NewClient consumes conn, so you should call Close on the returned
+// client not on the given conn.
 func NewConn(ctx context.Context, stream ObjectStream, h Handler, opts ...ConnOpt) *Conn {
-
-	ctx, cancel := context.WithCancel(ctx)
-
 	c := &Conn{
 		stream:     stream,
 		h:          h,
 		pending:    map[ID]*call{},
-		cancelCtx:  cancel,
 		disconnect: make(chan struct{}),
 		logger:     log.New(os.Stderr, "", log.LstdFlags),
 	}
@@ -67,12 +60,6 @@ func NewConn(ctx context.Context, stream ObjectStream, h Handler, opts ...ConnOp
 		opt(c)
 	}
 	go c.readMessages(ctx)
-
-	go func() {
-		<-ctx.Done()
-		c.close(nil)
-	}()
-
 	return c
 }
 
@@ -179,7 +166,9 @@ func (c *Conn) SendResponse(ctx context.Context, resp *Response) error {
 }
 
 func (c *Conn) close(cause error) error {
+	c.sending.Lock()
 	c.mu.Lock()
+	defer c.sending.Unlock()
 	defer c.mu.Unlock()
 
 	if c.closed {
@@ -195,23 +184,20 @@ func (c *Conn) close(cause error) error {
 	}
 
 	close(c.disconnect)
-	c.cancelCtx()
 	c.closed = true
 	return c.stream.Close()
 }
 
 func (c *Conn) readMessages(ctx context.Context) {
-	for {
+	var err error
+	for err == nil {
 		var m anyMessage
-		err := c.stream.ReadObject(&m)
+		err = c.stream.ReadObject(&m)
 		if err != nil {
-			c.close(err)
-			return
+			break
 		}
 
 		switch {
-		// TODO: handle the case where both request and response are nil.
-
 		case m.request != nil:
 			for _, onRecv := range c.onRecv {
 				onRecv(m.request, nil)
@@ -220,53 +206,49 @@ func (c *Conn) readMessages(ctx context.Context) {
 
 		case m.response != nil:
 			resp := m.response
-			id := resp.ID
-			c.mu.Lock()
-			call := c.pending[id]
-			delete(c.pending, id)
-			c.mu.Unlock()
+			if resp != nil {
+				id := resp.ID
+				c.mu.Lock()
+				call := c.pending[id]
+				delete(c.pending, id)
+				c.mu.Unlock()
 
-			var req *Request
-			if call != nil {
-				call.response = resp
-				req = call.request
+				if call != nil {
+					call.response = resp
+				}
+
+				if len(c.onRecv) > 0 {
+					var req *Request
+					if call != nil {
+						req = call.request
+					}
+					for _, onRecv := range c.onRecv {
+						onRecv(req, resp)
+					}
+				}
+
+				switch {
+				case call == nil:
+					c.logger.Printf("jsonrpc2: ignoring response #%s with no corresponding request\n", id)
+
+				case resp.Error != nil:
+					call.done <- resp.Error
+					close(call.done)
+
+				default:
+					call.done <- nil
+					close(call.done)
+				}
 			}
-
-			for _, onRecv := range c.onRecv {
-				onRecv(req, resp)
-			}
-
-			if call == nil {
-				c.logger.Printf("jsonrpc2: ignoring response #%s with no corresponding request\n", id)
-				continue
-			}
-
-			var err error
-			if resp.Error != nil {
-				err = resp.Error
-			}
-
-			call.done <- err
-			close(call.done)
 		}
 	}
+	c.close(err)
 }
 
 func (c *Conn) send(_ context.Context, m *anyMessage, wait bool) (cc *call, err error) {
 	c.sending.Lock()
 	defer c.sending.Unlock()
 
-	// double check the error isn't due to being closed while sending.
-	defer func() {
-		if err != nil {
-			c.mu.Lock()
-			if c.closed {
-				err = ErrClosed
-			}
-			c.mu.Unlock()
-		}
-	}()
-
 	// m.request.ID could be changed, so we store a copy to correctly
 	// clean up pending
 	var id ID
@@ -348,20 +330,25 @@ type Waiter struct {
 // error is returned.
 func (w Waiter) Wait(ctx context.Context, result interface{}) error {
 	select {
-	case <-ctx.Done():
-		return ctx.Err()
-
 	case err, ok := <-w.call.done:
 		if !ok {
-			return ErrClosed
+			err = ErrClosed
 		}
-		if err != nil || result == nil {
+		if err != nil {
 			return err
 		}
-		if w.call.response.Result == nil {
-			w.call.response.Result = &jsonNull
+		if result != nil {
+			if w.call.response.Result == nil {
+				w.call.response.Result = &jsonNull
+			}
+			if err := json.Unmarshal(*w.call.response.Result, result); err != nil {
+				return err
+			}
 		}
-		return json.Unmarshal(*w.call.response.Result, result)
+		return nil
+
+	case <-ctx.Done():
+		return ctx.Err()
 	}
 }
 
@@ -427,7 +414,12 @@ func (m *anyMessage) UnmarshalJSON(data []byte) error {
 			return errors.New("jsonrpc2: invalid empty batch")
 		}
 		for i := range msgs {
-			if err := checkType(&msgs[i]); err != nil {
+			if err := checkType(&msg{
+				ID:     msgs[i].ID,
+				Method: msgs[i].Method,
+				Result: msgs[i].Result,
+				Error:  msgs[i].Error,
+			}); err != nil {
 				return err
 			}
 		}

conn_opt.go

@@ -43,20 +43,6 @@ func LogMessages(logger Logger) ConnOpt {
 
 		OnRecv(func(req *Request, resp *Response) {
 			switch {
-			case resp != nil:
-				method := "(no matching request)"
-				if req != nil {
-					method = req.Method
-				}
-				switch {
-				case resp.Result != nil:
-					result, _ := json.Marshal(resp.Result)
-					logger.Printf("jsonrpc2: --> result #%s: %s: %s\n", resp.ID, method, result)
-				case resp.Error != nil:
-					err, _ := json.Marshal(resp.Error)
-					logger.Printf("jsonrpc2: --> error #%s: %s: %s\n", resp.ID, method, err)
-				}
-
 			case req != nil:
 				mu.Lock()
 				reqMethods[req.ID] = req.Method
@@ -68,10 +54,34 @@ func LogMessages(logger Logger) ConnOpt {
 				} else {
 					logger.Printf("jsonrpc2: --> request #%s: %s: %s\n", req.ID, req.Method, params)
 				}
+
+			case resp != nil:
+				var method string
+				if req != nil {
+					method = req.Method
+				} else {
+					method = "(no matching request)"
+				}
+				switch {
+				case resp.Result != nil:
+					result, _ := json.Marshal(resp.Result)
+					logger.Printf("jsonrpc2: --> result #%s: %s: %s\n", resp.ID, method, result)
+				case resp.Error != nil:
+					err, _ := json.Marshal(resp.Error)
+					logger.Printf("jsonrpc2: --> error #%s: %s: %s\n", resp.ID, method, err)
+				}
 			}
 		})(c)
 		OnSend(func(req *Request, resp *Response) {
 			switch {
+			case req != nil:
+				params, _ := json.Marshal(req.Params)
+				if req.Notif {
+					logger.Printf("jsonrpc2: <-- notif: %s: %s\n", req.Method, params)
+				} else {
+					logger.Printf("jsonrpc2: <-- request #%s: %s: %s\n", req.ID, req.Method, params)
+				}
+
 			case resp != nil:
 				mu.Lock()
 				method := reqMethods[resp.ID]
@@ -88,14 +98,6 @@ func LogMessages(logger Logger) ConnOpt {
 					err, _ := json.Marshal(resp.Error)
 					logger.Printf("jsonrpc2: <-- error #%s: %s: %s\n", resp.ID, method, err)
 				}
-
-			case req != nil:
-				params, _ := json.Marshal(req.Params)
-				if req.Notif {
-					logger.Printf("jsonrpc2: <-- notif: %s: %s\n", req.Method, params)
-				} else {
-					logger.Printf("jsonrpc2: <-- request #%s: %s: %s\n", req.ID, req.Method, params)
-				}
 			}
 		})(c)
 	}

conn_opt_test.go

@@ -51,80 +51,3 @@ func TestSetLogger(t *testing.T) {
 		t.Fatalf("got %q, want %q", got, want)
 	}
 }
-
-type dummyHandler struct {
-	t *testing.T
-}
-
-func (h *dummyHandler) Handle(ctx context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) {
-	if !req.Notif {
-		err := conn.Reply(ctx, req.ID, nil)
-		if err != nil {
-			h.t.Error(err)
-			return
-		}
-	}
-}
-
-func TestLogMessages(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	rd, wr := io.Pipe()
-	defer rd.Close()
-	defer wr.Close()
-
-	buf := bufio.NewReader(rd)
-	logger := log.New(wr, "", log.Lmsgprefix)
-
-	a, b := net.Pipe()
-	connA := jsonrpc2.NewConn(
-		ctx,
-		jsonrpc2.NewBufferedStream(a, jsonrpc2.VSCodeObjectCodec{}),
-		&dummyHandler{t},
-		jsonrpc2.LogMessages(logger),
-	)
-	connB := jsonrpc2.NewConn(
-		ctx,
-		jsonrpc2.NewBufferedStream(b, jsonrpc2.VSCodeObjectCodec{}),
-		&dummyHandler{t},
-	)
-	defer connA.Close()
-	defer connB.Close()
-
-	go func() {
-		if err := connA.Call(ctx, "method1", nil, nil); err != nil {
-			t.Error(err)
-			return
-		}
-		if err := connB.Call(ctx, "method2", nil, nil); err != nil {
-			t.Error(err)
-			return
-		}
-		if err := connA.Notify(ctx, "notification1", nil); err != nil {
-			t.Error(err)
-			return
-		}
-		if err := connB.Notify(ctx, "notification2", nil); err != nil {
-			t.Error(err)
-			return
-		}
-	}()
-
-	for i, want := range []string{
-		"jsonrpc2: <-- request #0: method1: null\n",
-		"jsonrpc2: --> result #0: method1: null\n",
-		"jsonrpc2: --> request #0: method2: null\n",
-		"jsonrpc2: <-- result #0: method2: null\n",
-		"jsonrpc2: <-- notif: notification1: null\n",
-		"jsonrpc2: --> notif: notification2: null\n",
-	} {
-		got, err := buf.ReadString('\n')
-		if err != nil {
-			t.Fatal(err)
-		}
-		if got != want {
-			t.Errorf("message %v: got %q, want %q", i, got, want)
-		}
-	}
-}

conn_test.go

@@ -14,58 +14,6 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func TestConn(t *testing.T) {
-
-	t.Run("closes when context is done", func(t *testing.T) {
-		ctx, cancel := context.WithCancel(context.Background())
-
-		connA, connB := Pipe(ctx, noopHandler{}, noopHandler{})
-		defer connA.Close()
-		defer connB.Close()
-
-		cancel()
-		<-connA.DisconnectNotify()
-
-		got := connA.Close()
-		want := jsonrpc2.ErrClosed
-		if got != want {
-			t.Fatalf("got %v, want %v", got, want)
-		}
-	})
-
-	t.Run("cancels context when closed", func(t *testing.T) {
-		ctxCanceled := make(chan struct{})
-
-		handler := handlerFunc(func(ctx context.Context, c *jsonrpc2.Conn, r *jsonrpc2.Request) {
-			// Block until the context is canceled.
-			<-ctx.Done()
-			close(ctxCanceled)
-		})
-
-		connA, connB := Pipe(context.Background(), noopHandler{}, jsonrpc2.AsyncHandler(handler))
-		defer connA.Close()
-		defer connB.Close()
-
-		// Send a notification from connA to connB to trigger connB's handler
-		// function.
-		if err := connA.Notify(context.Background(), "foo", nil, nil); err != nil {
-			t.Fatal(err)
-		}
-
-		// Disconnect connA from connB.
-		if err := connA.Close(); err != nil {
-			t.Fatal(err)
-		}
-
-		select {
-		case <-ctxCanceled:
-			// Test passed, the handler's context was canceled.
-		case <-time.After(time.Second):
-			t.Fatal("context not canceled")
-		}
-	})
-}
-
 var paramsTests = []struct {
 	sendParams interface{}
 	wantParams *json.RawMessage
@@ -170,77 +118,38 @@ func TestConn_DisconnectNotify(t *testing.T) {
 }
 
 func TestConn_Close(t *testing.T) {
-	cases := []struct {
-		name string
-		run  func(*testing.T, context.Context, *jsonrpc2.Conn)
-	}{{
-		name: "during Call",
-		run: func(t *testing.T, ctx context.Context, conn *jsonrpc2.Conn) {
-			ready := make(chan struct{})
-			done := make(chan struct{})
-			go func() {
-				close(ready)
-				err := conn.Call(ctx, "m", nil, nil)
-				if err != jsonrpc2.ErrClosed {
-					t.Errorf("got error %v, want %v", err, jsonrpc2.ErrClosed)
-				}
-				close(done)
-			}()
-			// Wait for the request to be sent before we close the connection.
-			<-ready
-			if err := conn.Close(); err != nil && err != jsonrpc2.ErrClosed {
-				t.Error(err)
-			}
-			<-done
-		},
-	}, {
-		name: "during Wait",
-		run: func(t *testing.T, ctx context.Context, conn *jsonrpc2.Conn) {
-			call, err := conn.DispatchCall(ctx, "m", nil, nil)
-			if err != nil {
-				t.Fatal(err)
-			}
-			if err := conn.Close(); err != nil {
-				t.Fatal(err)
-			}
-			if err := call.Wait(ctx, nil); err != jsonrpc2.ErrClosed {
-				t.Fatal(err)
-			}
-		},
-	}, {
-		name: "during Dispatch",
-		run: func(t *testing.T, ctx context.Context, conn *jsonrpc2.Conn) {
-			if err := conn.Close(); err != nil {
-				t.Fatal(err)
-			}
-			if _, err := conn.DispatchCall(ctx, "m", nil, nil); err != jsonrpc2.ErrClosed {
-				t.Fatal(err)
-			}
-		},
-	}}
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			ctx, cancel := context.WithCancel(context.Background())
-			defer cancel()
+	t.Run("waiting for response", func(t *testing.T) {
+		connA, connB := net.Pipe()
+		nodeA := jsonrpc2.NewConn(
+			context.Background(),
+			jsonrpc2.NewPlainObjectStream(connA), noopHandler{},
+		)
+		defer nodeA.Close()
+		nodeB := jsonrpc2.NewConn(
+			context.Background(),
+			jsonrpc2.NewPlainObjectStream(connB),
+			noopHandler{},
+		)
+		defer nodeB.Close()
 
-			connA, connB := net.Pipe()
-			nodeA := jsonrpc2.NewConn(
-				ctx,
-				jsonrpc2.NewPlainObjectStream(connA), noopHandler{},
-			)
-			defer nodeA.Close()
-			nodeB := jsonrpc2.NewConn(
-				ctx,
-				jsonrpc2.NewPlainObjectStream(connB),
-				noopHandler{},
-			)
-			defer nodeB.Close()
-
-			tc.run(t, ctx, nodeB)
-
-			assertDisconnect(t, nodeB, connB)
-		})
-	}
+		ready := make(chan struct{})
+		done := make(chan struct{})
+		go func() {
+			close(ready)
+			err := nodeB.Call(context.Background(), "m", nil, nil)
+			if err != jsonrpc2.ErrClosed {
+				t.Errorf("got error %v, want %v", err, jsonrpc2.ErrClosed)
+			}
+			close(done)
+		}()
+		// Wait for the request to be sent before we close the connection.
+		<-ready
+		if err := nodeB.Close(); err != nil && err != jsonrpc2.ErrClosed {
+			t.Error(err)
+		}
+		assertDisconnect(t, nodeB, connB)
+		<-done
+	})
 }
 
 func testParams(t *testing.T, want *json.RawMessage, fn func(c *jsonrpc2.Conn) error) {
@@ -250,12 +159,12 @@ func testParams(t *testing.T, want *json.RawMessage, fn func(c *jsonrpc2.Conn) e
 		wg.Done()
 	})
 
-	connA, connB := Pipe(context.Background(), noopHandler{}, handler)
-	defer connA.Close()
-	defer connB.Close()
+	client, server := newClientServer(handler)
+	defer client.Close()
+	defer server.Close()
 
 	wg.Add(1)
-	if err := fn(connA); err != nil {
+	if err := fn(client); err != nil {
 		t.Error(err)
 	}
 	wg.Wait()
@@ -294,11 +203,18 @@ func assertRawJSONMessage(t *testing.T, got *json.RawMessage, want *json.RawMess
 	}
 }
 
-// Pipe returns two jsonrpc2.Conn, connected via a synchronous, in-memory, full
-// duplex network connection.
-func Pipe(ctx context.Context, handlerA, handlerB jsonrpc2.Handler) (connA *jsonrpc2.Conn, connB *jsonrpc2.Conn) {
-	a, b := net.Pipe()
-	connA = jsonrpc2.NewConn(ctx, jsonrpc2.NewPlainObjectStream(a), handlerA)
-	connB = jsonrpc2.NewConn(ctx, jsonrpc2.NewPlainObjectStream(b), handlerB)
-	return connA, connB
+func newClientServer(handler jsonrpc2.Handler) (client *jsonrpc2.Conn, server *jsonrpc2.Conn) {
+	ctx := context.Background()
+	connA, connB := net.Pipe()
+	client = jsonrpc2.NewConn(
+		ctx,
+		jsonrpc2.NewPlainObjectStream(connA),
+		noopHandler{},
+	)
+	server = jsonrpc2.NewConn(
+		ctx,
+		jsonrpc2.NewPlainObjectStream(connB),
+		handler,
+	)
+	return client, server
 }

example_params_test.go

@@ -1,78 +0,0 @@
-package jsonrpc2_test
-
-import (
-	"context"
-	"encoding/json"
-	"fmt"
-	"net"
-	"os"
-
-	"github.com/sourcegraph/jsonrpc2"
-)
-
-// Send a JSON-RPC notification with its params member omitted.
-func ExampleConn_Notify_paramsOmitted() {
-	ctx := context.Background()
-
-	connA, connB := net.Pipe()
-	defer connA.Close()
-	defer connB.Close()
-
-	rpcConn := jsonrpc2.NewConn(ctx, jsonrpc2.NewPlainObjectStream(connA), nil)
-
-	// Send the JSON-RPC notification.
-	go func() {
-		// Set params to nil.
-		if err := rpcConn.Notify(ctx, "foo", nil); err != nil {
-			fmt.Fprintln(os.Stderr, "notify:", err)
-		}
-	}()
-
-	// Read the raw JSON-RPC notification on connB.
-	//
-	// Reading the raw JSON-RPC request is for the purpose of this example only.
-	// Use a jsonrpc2.Handler to read parsed requests.
-	buf := make([]byte, 64)
-	n, err := connB.Read(buf)
-	if err != nil {
-		fmt.Fprintln(os.Stderr, "read:", err)
-	}
-
-	fmt.Printf("%s\n", buf[:n])
-
-	// Output: {"jsonrpc":"2.0","method":"foo"}
-}
-
-// Send a JSON-RPC notification with its params member set to null.
-func ExampleConn_Notify_nullParams() {
-	ctx := context.Background()
-
-	connA, connB := net.Pipe()
-	defer connA.Close()
-	defer connB.Close()
-
-	rpcConn := jsonrpc2.NewConn(ctx, jsonrpc2.NewPlainObjectStream(connA), nil)
-
-	// Send the JSON-RPC notification.
-	go func() {
-		// Set params to the JSON null value.
-		params := json.RawMessage("null")
-		if err := rpcConn.Notify(ctx, "foo", params); err != nil {
-			fmt.Fprintln(os.Stderr, "notify:", err)
-		}
-	}()
-
-	// Read the raw JSON-RPC notification on connB.
-	//
-	// Reading the raw JSON-RPC request is for the purpose of this example only.
-	// Use a jsonrpc2.Handler to read parsed requests.
-	buf := make([]byte, 64)
-	n, err := connB.Read(buf)
-	if err != nil {
-		fmt.Fprintln(os.Stderr, "read:", err)
-	}
-
-	fmt.Printf("%s\n", buf[:n])
-
-	// Output: {"jsonrpc":"2.0","method":"foo","params":null}
-}

example_test.go

@@ -2,63 +2,77 @@ package jsonrpc2_test
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
-	"log"
 	"net"
 	"os"
 
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func Example() {
+// Send a JSON-RPC notification with its params member omitted.
+func ExampleConn_Notify_paramsOmitted() {
 	ctx := context.Background()
 
-	// Create an in-memory network connection. This connection is used below to
-	// transport the JSON-RPC messages. However, any io.ReadWriteCloser may be
-	// used to send/receive JSON-RPC messages.
 	connA, connB := net.Pipe()
+	defer connA.Close()
+	defer connB.Close()
 
-	// The following JSON-RPC connection is both a client and a server. It can
-	// send requests as well as receive requests. The incoming requests are
-	// handled by myHandler.
-	jsonrpcConnA := jsonrpc2.NewConn(ctx, jsonrpc2.NewPlainObjectStream(connA), &myHandler{})
-	defer jsonrpcConnA.Close()
+	rpcConn := jsonrpc2.NewConn(ctx, jsonrpc2.NewPlainObjectStream(connA), nil)
 
-	// The following JSON-RPC connection has no handler, meaning that it is
-	// configured to only be a client. It can send requests and receive the
-	// responses to those requests, but it will ignore any incoming requests.
-	jsonrpcConnB := jsonrpc2.NewConn(ctx, jsonrpc2.NewPlainObjectStream(connB), nil)
-	defer jsonrpcConnB.Close()
+	// Send the JSON-RPC notification.
+	go func() {
+		// Set params to nil.
+		if err := rpcConn.Notify(ctx, "foo", nil); err != nil {
+			fmt.Fprintln(os.Stderr, "notify:", err)
+		}
+	}()
 
-	// Send a request from jsonrpcConnB to jsonrpcConnA. The result of a
-	// successful call is stored in the result variable.
-	var result string
-	if err := jsonrpcConnB.Call(ctx, "sayHello", nil, &result); err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		return
+	// Read the raw JSON-RPC notification on connB.
+	//
+	// Reading the raw JSON-RPC request is for the purpose of this example only.
+	// Use a jsonrpc2.Handler to read parsed requests.
+	buf := make([]byte, 64)
+	n, err := connB.Read(buf)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "read:", err)
 	}
 
-	fmt.Println(result)
+	fmt.Printf("%s\n", buf[:n])
 
-	// Output: hello world
+	// Output: {"jsonrpc":"2.0","method":"foo"}
 }
 
-// myHandler is the jsonrpc2.Handler used by jsonrpcConnA.
-type myHandler struct{}
+// Send a JSON-RPC notification with its params member set to null.
+func ExampleConn_Notify_nullParams() {
+	ctx := context.Background()
 
-// Handle implements the jsonrpc2.Handler interface.
-func (h *myHandler) Handle(ctx context.Context, c *jsonrpc2.Conn, r *jsonrpc2.Request) {
-	switch r.Method {
-	case "sayHello":
-		if err := c.Reply(ctx, r.ID, "hello world"); err != nil {
-			log.Println(err)
-			return
-		}
-	default:
-		err := &jsonrpc2.Error{Code: jsonrpc2.CodeMethodNotFound, Message: "Method not found"}
-		if err := c.ReplyWithError(ctx, r.ID, err); err != nil {
-			log.Println(err)
-			return
+	connA, connB := net.Pipe()
+	defer connA.Close()
+	defer connB.Close()
+
+	rpcConn := jsonrpc2.NewConn(ctx, jsonrpc2.NewPlainObjectStream(connA), nil)
+
+	// Send the JSON-RPC notification.
+	go func() {
+		// Set params to the JSON null value.
+		params := json.RawMessage("null")
+		if err := rpcConn.Notify(ctx, "foo", params); err != nil {
+			fmt.Fprintln(os.Stderr, "notify:", err)
 		}
+	}()
+
+	// Read the raw JSON-RPC notification on connB.
+	//
+	// Reading the raw JSON-RPC request is for the purpose of this example only.
+	// Use a jsonrpc2.Handler to read parsed requests.
+	buf := make([]byte, 64)
+	n, err := connB.Read(buf)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "read:", err)
 	}
+
+	fmt.Printf("%s\n", buf[:n])
+
+	// Output: {"jsonrpc":"2.0","method":"foo","params":null}
 }

handler_with_error.go

@@ -30,16 +30,20 @@ func (h *HandlerWithErrorConfigurer) Handle(ctx context.Context, conn *Conn, req
 	if err == nil {
 		err = resp.SetResult(result)
 	}
-
-	if e, ok := err.(*Error); ok {
-		resp.Error = e
-	} else if err != nil {
-		resp.Error = &Error{Message: err.Error()}
+	if err != nil {
+		if e, ok := err.(*Error); ok {
+			resp.Error = e
+		} else {
+			resp.Error = &Error{Message: err.Error()}
+		}
 	}
 
-	err = conn.SendResponse(ctx, resp)
-	if err != nil && (err != ErrClosed || !h.suppressErrClosed) {
-		conn.logger.Printf("jsonrpc2 handler: sending response %s: %v\n", resp.ID, err)
+	if !req.Notif {
+		if err := conn.SendResponse(ctx, resp); err != nil {
+			if err != ErrClosed || !h.suppressErrClosed {
+				conn.logger.Printf("jsonrpc2 handler: sending response %s: %v\n", resp.ID, err)
+			}
+		}
 	}
 }
 

jsonrpc2.go

@@ -59,10 +59,10 @@ const (
 
 // Handler handles JSON-RPC requests and notifications.
 type Handler interface {
-	// Handle is called to handle a request. No other requests are handled until
-	// it returns. If you do not require strict ordering behavior of received
-	// RPCs, it is suggested to wrap your handler in AsyncHandler. The context
-	// is automatically canceled when the connection closes.
+	// Handle is called to handle a request. No other requests are handled
+	// until it returns. If you do not require strict ordering behavior
+	// of received RPCs, it is suggested to wrap your handler in
+	// AsyncHandler.
 	Handle(context.Context, *Conn, *Request)
 }
 

request.go

@@ -55,10 +55,6 @@ func (r Request) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON implements json.Unmarshaler.
 func (r *Request) UnmarshalJSON(data []byte) error {
 	r2 := make(map[string]interface{})
-	pop := func(key string) interface{} {
-		defer delete(r2, key)
-		return r2[key]
-	}
 
 	// Detect if the "params" or "meta" fields are JSON "null" or just not
 	// present by seeing if the field gets overwritten to nil.
@@ -72,37 +68,36 @@ func (r *Request) UnmarshalJSON(data []byte) error {
 	if err := decoder.Decode(&r2); err != nil {
 		return err
 	}
-
 	var ok bool
-	r.Method, ok = pop("method").(string)
+	r.Method, ok = r2["method"].(string)
 	if !ok {
 		return errors.New("missing method field")
 	}
-	switch params := pop("params"); params {
-	case nil:
+	switch {
+	case r2["params"] == nil:
 		r.Params = &jsonNull
-	case emptyParams:
+	case r2["params"] == emptyParams:
 		r.Params = nil
 	default:
-		b, err := json.Marshal(params)
+		b, err := json.Marshal(r2["params"])
 		if err != nil {
 			return fmt.Errorf("failed to marshal params: %w", err)
 		}
 		r.Params = (*json.RawMessage)(&b)
 	}
-	switch meta := pop("meta"); meta {
-	case nil:
+	switch {
+	case r2["meta"] == nil:
 		r.Meta = &jsonNull
-	case emptyMeta:
+	case r2["meta"] == emptyMeta:
 		r.Meta = nil
 	default:
-		b, err := json.Marshal(meta)
+		b, err := json.Marshal(r2["meta"])
 		if err != nil {
 			return fmt.Errorf("failed to marshal Meta: %w", err)
 		}
 		r.Meta = (*json.RawMessage)(&b)
 	}
-	switch rawID := pop("id").(type) {
+	switch rawID := r2["id"].(type) {
 	case nil:
 		r.ID = ID{}
 		r.Notif = true
@@ -120,12 +115,13 @@ func (r *Request) UnmarshalJSON(data []byte) error {
 		return fmt.Errorf("unexpected ID type: %T", rawID)
 	}
 
-	// The jsonrpc field should not be added to ExtraFields.
-	delete(r2, "jsonrpc")
-
 	// Clear the extra fields before populating them again.
 	r.ExtraFields = nil
 	for name, value := range r2 {
+		switch name {
+		case "id", "jsonrpc", "meta", "method", "params":
+			continue
+		}
 		r.ExtraFields = append(r.ExtraFields, RequestField{
 			Name:  name,
 			Value: value,