whatcanGOwrong

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/.github/workflows/lsif.yml

@@ -0,0 +1,16 @@
+name: LSIF
+on:
+  - push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Generate LSIF data
+        uses: sourcegraph/lsif-go-action@master
+        with:
+          verbose: "true"
+      - name: Upload LSIF data
+        uses: sourcegraph/lsif-upload-action@master
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/.travis.yml

@@ -0,0 +1,6 @@
+language: go
+go: 
+ - 1.x
+
+script:
+ - go test -race -v ./...

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/LICENSE

@@ -0,0 +1,9 @@
+Copyright (c) 2016 Sourcegraph Inc
+
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/README.md

@@ -0,0 +1,12 @@
+# jsonrpc2: JSON-RPC 2.0 implementation for Go [![Build Status](https://travis-ci.org/sourcegraph/jsonrpc2.svg)](https://travis-ci.org/sourcegraph/jsonrpc2) [![Sourcegraph](https://sourcegraph.com/github.com/sourcegraph/jsonrpc2/-/badge.svg)](https://sourcegraph.com/github.com/sourcegraph/jsonrpc2?badge) [![GoDoc](https://godoc.org/github.com/sourcegraph/jsonrpc2?status.svg)](https://godoc.org/github.com/sourcegraph/jsonrpc2)
+
+
+Package jsonrpc2 provides a [Go](https://golang.org) implementation of [JSON-RPC 2.0](http://www.jsonrpc.org/specification).
+
+This package is **experimental** until further notice.
+
+[**Open the code in Sourcegraph**](https://sourcegraph.com/github.com/sourcegraph/jsonrpc2)
+
+## Known issues
+
+* Batch requests and responses are not yet supported.

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/async.go

@@ -0,0 +1,17 @@
+package jsonrpc2
+
+import "context"
+
+// AsyncHandler wraps a Handler such that each request is handled in its own
+// goroutine. It is a convenience wrapper.
+func AsyncHandler(h Handler) Handler {
+	return asyncHandler{h}
+}
+
+type asyncHandler struct {
+	Handler
+}
+
+func (h asyncHandler) Handle(ctx context.Context, conn *Conn, req *Request) {
+	go h.Handler.Handle(ctx, conn, req)
+}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/call_opt.go

@@ -0,0 +1,30 @@
+package jsonrpc2
+
+// CallOption is an option that can be provided to (*Conn).Call to
+// configure custom behavior. See Meta.
+type CallOption interface {
+	apply(r *Request) error
+}
+
+type callOptionFunc func(r *Request) error
+
+func (c callOptionFunc) apply(r *Request) error { return c(r) }
+
+// Meta returns a call option which attaches the given meta object to
+// the JSON-RPC 2.0 request (this is a Sourcegraph extension to JSON
+// RPC 2.0 for carrying metadata).
+func Meta(meta interface{}) CallOption {
+	return callOptionFunc(func(r *Request) error {
+		return r.SetMeta(meta)
+	})
+}
+
+// PickID returns a call option which sets the ID on a request. Care must be
+// taken to ensure there are no conflicts with any previously picked ID, nor
+// with the default sequence ID.
+func PickID(id ID) CallOption {
+	return callOptionFunc(func(r *Request) error {
+		r.ID = id
+		return nil
+	})
+}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/codec_test.go

@@ -0,0 +1,34 @@
+package jsonrpc2
+
+import (
+	"bufio"
+	"bytes"
+	"strings"
+	"testing"
+)
+
+func TestVarintObjectCodec(t *testing.T) {
+	want := 789
+	var buf bytes.Buffer
+	if err := (VarintObjectCodec{}).WriteObject(&buf, want); err != nil {
+		t.Fatal(err)
+	}
+	var v int
+	if err := (VarintObjectCodec{}).ReadObject(bufio.NewReader(&buf), &v); err != nil {
+		t.Fatal(err)
+	}
+	if want := want; v != want {
+		t.Errorf("got %v, want %v", v, want)
+	}
+}
+
+func TestVSCodeObjectCodec_ReadObject(t *testing.T) {
+	s := "Content-Type: foo\r\nContent-Length: 123\r\n\r\n789"
+	var v int
+	if err := (VSCodeObjectCodec{}).ReadObject(bufio.NewReader(strings.NewReader(s)), &v); err != nil {
+		t.Fatal(err)
+	}
+	if want := 789; v != want {
+		t.Errorf("got %v, want %v", v, want)
+	}
+}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/conn_opt.go

@@ -0,0 +1,104 @@
+package jsonrpc2
+
+import (
+	"encoding/json"
+	"sync"
+)
+
+// Logger interface implements one method - Printf.
+// You can use the stdlib logger *log.Logger
+type Logger interface {
+	Printf(format string, v ...interface{})
+}
+
+// ConnOpt is the type of function that can be passed to NewConn to
+// customize the Conn before it is created.
+type ConnOpt func(*Conn)
+
+// OnRecv causes all requests received on conn to invoke f(req, nil)
+// and all responses to invoke f(req, resp),
+func OnRecv(f func(*Request, *Response)) ConnOpt {
+	return func(c *Conn) { c.onRecv = append(c.onRecv, f) }
+}
+
+// OnSend causes all requests sent on conn to invoke f(req, nil) and
+// all responses to invoke f(nil, resp),
+func OnSend(f func(*Request, *Response)) ConnOpt {
+	return func(c *Conn) { c.onSend = append(c.onSend, f) }
+}
+
+// LogMessages causes all messages sent and received on conn to be
+// logged using the provided logger.
+func LogMessages(logger Logger) ConnOpt {
+	return func(c *Conn) {
+		// Remember reqs we have received so we can helpfully show the
+		// request method in OnSend for responses.
+		var (
+			mu         sync.Mutex
+			reqMethods = map[ID]string{}
+		)
+
+		// Set custom logger from provided input
+		c.logger = logger
+
+		OnRecv(func(req *Request, resp *Response) {
+			switch {
+			case req != nil:
+				mu.Lock()
+				reqMethods[req.ID] = req.Method
+				mu.Unlock()
+
+				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:
+				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]
+				delete(reqMethods, resp.ID)
+				mu.Unlock()
+				if method == "" {
+					method = "(no previous request)"
+				}
+
+				if resp.Result != nil {
+					result, _ := json.Marshal(resp.Result)
+					logger.Printf("jsonrpc2: <-- result #%s: %s: %s\n", resp.ID, method, result)
+				} else {
+					err, _ := json.Marshal(resp.Error)
+					logger.Printf("jsonrpc2: <-- error #%s: %s: %s\n", resp.ID, method, err)
+				}
+			}
+		})(c)
+	}
+}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/go.mod

@@ -0,0 +1,5 @@
+module github.com/sourcegraph/jsonrpc2
+
+go 1.12
+
+require github.com/gorilla/websocket v1.4.1

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/go.sum

@@ -0,0 +1,2 @@
+github.com/gorilla/websocket v1.4.1 h1:q7AeDBpnBk8AogcD4DSag/Ukw/KV+YhzLj2bP5HvKCM=
+github.com/gorilla/websocket v1.4.1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/handler_with_error.go

@@ -0,0 +1,64 @@
+package jsonrpc2
+
+import (
+	"context"
+)
+
+// HandlerWithError implements Handler by calling the func for each
+// request and handling returned errors and results.
+func HandlerWithError(handleFunc func(context.Context, *Conn, *Request) (result interface{}, err error)) *HandlerWithErrorConfigurer {
+	return &HandlerWithErrorConfigurer{handleFunc: handleFunc}
+}
+
+// HandlerWithErrorConfigurer is a handler created by HandlerWithError.
+type HandlerWithErrorConfigurer struct {
+	handleFunc        func(context.Context, *Conn, *Request) (result interface{}, err error)
+	suppressErrClosed bool
+}
+
+// Handle implements Handler.
+func (h *HandlerWithErrorConfigurer) Handle(ctx context.Context, conn *Conn, req *Request) {
+	result, err := h.handleFunc(ctx, conn, req)
+	if req.Notif {
+		if err != nil {
+			conn.logger.Printf("jsonrpc2 handler: notification %q handling error: %v\n", req.Method, err)
+		}
+		return
+	}
+
+	resp := &Response{ID: req.ID}
+	if err == nil {
+		err = resp.SetResult(result)
+	}
+	if err != nil {
+		if e, ok := err.(*Error); ok {
+			resp.Error = e
+		} else {
+			resp.Error = &Error{Message: err.Error()}
+		}
+	}
+
+	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)
+			}
+		}
+	}
+}
+
+// SuppressErrClosed makes the handler suppress jsonrpc2.ErrClosed errors from
+// being logged. The original handler `h` is returned.
+//
+// This is optional because only in some cases is this behavior desired. For
+// example, a handler that serves end-user connections may not want to log
+// ErrClosed because it just indicates the end-user connection has gone away
+// for any reason (they could have lost wifi connection, are no longer
+// interested in the request and closed the connection, etc) and as such it
+// would be log spam, whereas a handler that serves internal connections would
+// never expect connections to go away unexpectedly (which could indicate
+// service degradation, etc) and as such ErrClosed should always be logged.
+func (h *HandlerWithErrorConfigurer) SuppressErrClosed() Handler {
+	h.suppressErrClosed = true
+	return h
+}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/jsonrpc2.go

@@ -0,0 +1,702 @@
+// Package jsonrpc2 provides a client and server implementation of
+// [JSON-RPC 2.0](http://www.jsonrpc.org/specification).
+package jsonrpc2
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strconv"
+	"sync"
+)
+
+// JSONRPC2 describes an interface for issuing requests that speak the
+// JSON-RPC 2 protocol.  It isn't really necessary for this package
+// itself, but is useful for external users that use the interface as
+// an API boundary.
+type JSONRPC2 interface {
+	// Call issues a standard request (http://www.jsonrpc.org/specification#request_object).
+	Call(ctx context.Context, method string, params, result interface{}, opt ...CallOption) error
+
+	// Notify issues a notification request (http://www.jsonrpc.org/specification#notification).
+	Notify(ctx context.Context, method string, params interface{}, opt ...CallOption) error
+
+	// Close closes the underlying connection, if it exists.
+	Close() error
+}
+
+// Request represents a JSON-RPC request or
+// notification. See
+// http://www.jsonrpc.org/specification#request_object and
+// http://www.jsonrpc.org/specification#notification.
+type Request struct {
+	Method string           `json:"method"`
+	Params *json.RawMessage `json:"params,omitempty"`
+	ID     ID               `json:"id"`
+	Notif  bool             `json:"-"`
+
+	// Meta optionally provides metadata to include in the request.
+	//
+	// NOTE: It is not part of spec. However, it is useful for propogating
+	// tracing context, etc.
+	Meta *json.RawMessage `json:"meta,omitempty"`
+}
+
+// MarshalJSON implements json.Marshaler and adds the "jsonrpc":"2.0"
+// property.
+func (r Request) MarshalJSON() ([]byte, error) {
+	r2 := struct {
+		Method  string           `json:"method"`
+		Params  *json.RawMessage `json:"params,omitempty"`
+		ID      *ID              `json:"id,omitempty"`
+		Meta    *json.RawMessage `json:"meta,omitempty"`
+		JSONRPC string           `json:"jsonrpc"`
+	}{
+		Method:  r.Method,
+		Params:  r.Params,
+		Meta:    r.Meta,
+		JSONRPC: "2.0",
+	}
+	if !r.Notif {
+		r2.ID = &r.ID
+	}
+	return json.Marshal(r2)
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (r *Request) UnmarshalJSON(data []byte) error {
+	var r2 struct {
+		Method string           `json:"method"`
+		Params *json.RawMessage `json:"params,omitempty"`
+		Meta   *json.RawMessage `json:"meta,omitempty"`
+		ID     *ID              `json:"id"`
+	}
+
+	// Detect if the "params" field is JSON "null" or just not present
+	// by seeing if the field gets overwritten to nil.
+	r2.Params = &json.RawMessage{}
+
+	if err := json.Unmarshal(data, &r2); err != nil {
+		return err
+	}
+	r.Method = r2.Method
+	switch {
+	case r2.Params == nil:
+		r.Params = &jsonNull
+	case len(*r2.Params) == 0:
+		r.Params = nil
+	default:
+		r.Params = r2.Params
+	}
+	r.Meta = r2.Meta
+	if r2.ID == nil {
+		r.ID = ID{}
+		r.Notif = true
+	} else {
+		r.ID = *r2.ID
+		r.Notif = false
+	}
+	return nil
+}
+
+// SetParams sets r.Params to the JSON representation of v. If JSON
+// marshaling fails, it returns an error.
+func (r *Request) SetParams(v interface{}) error {
+	b, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	r.Params = (*json.RawMessage)(&b)
+	return nil
+}
+
+// SetMeta sets r.Meta to the JSON representation of v. If JSON
+// marshaling fails, it returns an error.
+func (r *Request) SetMeta(v interface{}) error {
+	b, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	r.Meta = (*json.RawMessage)(&b)
+	return nil
+}
+
+// Response represents a JSON-RPC response. See
+// http://www.jsonrpc.org/specification#response_object.
+type Response struct {
+	ID     ID               `json:"id"`
+	Result *json.RawMessage `json:"result,omitempty"`
+	Error  *Error           `json:"error,omitempty"`
+
+	// Meta optionally provides metadata to include in the response.
+	//
+	// NOTE: It is not part of spec. However, it is useful for propogating
+	// tracing context, etc.
+	Meta *json.RawMessage `json:"meta,omitempty"`
+
+	// SPEC NOTE: The spec says "If there was an error in detecting
+	// the id in the Request object (e.g. Parse error/Invalid
+	// Request), it MUST be Null." If we made the ID field nullable,
+	// then we'd have to make it a pointer type. For simplicity, we're
+	// ignoring the case where there was an error in detecting the ID
+	// in the Request object.
+}
+
+// MarshalJSON implements json.Marshaler and adds the "jsonrpc":"2.0"
+// property.
+func (r Response) MarshalJSON() ([]byte, error) {
+	if (r.Result == nil || len(*r.Result) == 0) && r.Error == nil {
+		return nil, errors.New("can't marshal *jsonrpc2.Response (must have result or error)")
+	}
+	type tmpType Response // avoid infinite MarshalJSON recursion
+	b, err := json.Marshal(tmpType(r))
+	if err != nil {
+		return nil, err
+	}
+	b = append(b[:len(b)-1], []byte(`,"jsonrpc":"2.0"}`)...)
+	return b, nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (r *Response) UnmarshalJSON(data []byte) error {
+	type tmpType Response
+
+	// Detect if the "result" field is JSON "null" or just not present
+	// by seeing if the field gets overwritten to nil.
+	*r = Response{Result: &json.RawMessage{}}
+
+	if err := json.Unmarshal(data, (*tmpType)(r)); err != nil {
+		return err
+	}
+	if r.Result == nil { // JSON "null"
+		r.Result = &jsonNull
+	} else if len(*r.Result) == 0 {
+		r.Result = nil
+	}
+	return nil
+}
+
+// SetResult sets r.Result to the JSON representation of v. If JSON
+// marshaling fails, it returns an error.
+func (r *Response) SetResult(v interface{}) error {
+	b, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	r.Result = (*json.RawMessage)(&b)
+	return nil
+}
+
+// Error represents a JSON-RPC response error.
+type Error struct {
+	Code    int64            `json:"code"`
+	Message string           `json:"message"`
+	Data    *json.RawMessage `json:"data"`
+}
+
+// SetError sets e.Error to the JSON representation of v. If JSON
+// marshaling fails, it panics.
+func (e *Error) SetError(v interface{}) {
+	b, err := json.Marshal(v)
+	if err != nil {
+		panic("Error.SetData: " + err.Error())
+	}
+	e.Data = (*json.RawMessage)(&b)
+}
+
+// Error implements the Go error interface.
+func (e *Error) Error() string {
+	return fmt.Sprintf("jsonrpc2: code %v message: %s", e.Code, e.Message)
+}
+
+// Errors defined in the JSON-RPC spec. See
+// http://www.jsonrpc.org/specification#error_object.
+const (
+	CodeParseError     = -32700
+	CodeInvalidRequest = -32600
+	CodeMethodNotFound = -32601
+	CodeInvalidParams  = -32602
+	CodeInternalError  = -32603
+)
+
+// 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.
+	Handle(context.Context, *Conn, *Request)
+}
+
+// ID represents a JSON-RPC 2.0 request ID, which may be either a
+// string or number (or null, which is unsupported).
+type ID struct {
+	// At most one of Num or Str may be nonzero. If both are zero
+	// valued, then IsNum specifies which field's value is to be used
+	// as the ID.
+	Num uint64
+	Str string
+
+	// IsString controls whether the Num or Str field's value should be
+	// used as the ID, when both are zero valued. It must always be
+	// set to true if the request ID is a string.
+	IsString bool
+}
+
+func (id ID) String() string {
+	if id.IsString {
+		return strconv.Quote(id.Str)
+	}
+	return strconv.FormatUint(id.Num, 10)
+}
+
+// MarshalJSON implements json.Marshaler.
+func (id ID) MarshalJSON() ([]byte, error) {
+	if id.IsString {
+		return json.Marshal(id.Str)
+	}
+	return json.Marshal(id.Num)
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (id *ID) UnmarshalJSON(data []byte) error {
+	// Support both uint64 and string IDs.
+	var v uint64
+	if err := json.Unmarshal(data, &v); err == nil {
+		*id = ID{Num: v}
+		return nil
+	}
+	var v2 string
+	if err := json.Unmarshal(data, &v2); err != nil {
+		return err
+	}
+	*id = ID{Str: v2, IsString: true}
+	return nil
+}
+
+// Conn is a JSON-RPC client/server connection. The JSON-RPC protocol
+// is symmetric, so a Conn runs on both ends of a client-server
+// connection.
+type Conn struct {
+	stream ObjectStream
+
+	h Handler
+
+	mu       sync.Mutex
+	shutdown bool
+	closing  bool
+	seq      uint64
+	pending  map[ID]*call
+
+	sending sync.Mutex
+
+	disconnect chan struct{}
+
+	logger Logger
+
+	// Set by ConnOpt funcs.
+	onRecv []func(*Request, *Response)
+	onSend []func(*Request, *Response)
+}
+
+var _ JSONRPC2 = (*Conn)(nil)
+
+// ErrClosed indicates that the JSON-RPC connection is closed (or in
+// the process of closing).
+var ErrClosed = errors.New("jsonrpc2: connection is closed")
+
+// NewConn creates a new JSON-RPC client/server connection using the
+// given ReadWriteCloser (typically a TCP connection or stdio). The
+// JSON-RPC protocol is symmetric, so a Conn runs on both ends of a
+// client-server connection.
+//
+// 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 {
+	c := &Conn{
+		stream:     stream,
+		h:          h,
+		pending:    map[ID]*call{},
+		disconnect: make(chan struct{}),
+		logger:     log.New(os.Stderr, "", log.LstdFlags),
+	}
+	for _, opt := range opts {
+		if opt == nil {
+			continue
+		}
+		opt(c)
+	}
+	go c.readMessages(ctx)
+	return c
+}
+
+// Close closes the JSON-RPC connection. The connection may not be
+// used after it has been closed.
+func (c *Conn) Close() error {
+	c.mu.Lock()
+	if c.shutdown || c.closing {
+		c.mu.Unlock()
+		return ErrClosed
+	}
+	c.closing = true
+	c.mu.Unlock()
+	return c.stream.Close()
+}
+
+func (c *Conn) send(_ context.Context, m *anyMessage, wait bool) (cc *call, err error) {
+	c.sending.Lock()
+	defer c.sending.Unlock()
+
+	// m.request.ID could be changed, so we store a copy to correctly
+	// clean up pending
+	var id ID
+
+	c.mu.Lock()
+	if c.shutdown || c.closing {
+		c.mu.Unlock()
+		return nil, ErrClosed
+	}
+
+	// Store requests so we can later associate them with incoming
+	// responses.
+	if m.request != nil && wait {
+		cc = &call{request: m.request, seq: c.seq, done: make(chan error, 1)}
+		if !m.request.ID.IsString && m.request.ID.Num == 0 {
+			// unset, use next seq as call ID
+			m.request.ID.Num = c.seq
+		}
+		id = m.request.ID
+		c.pending[id] = cc
+		c.seq++
+	}
+	c.mu.Unlock()
+
+	if len(c.onSend) > 0 {
+		var (
+			req  *Request
+			resp *Response
+		)
+		switch {
+		case m.request != nil:
+			req = m.request
+		case m.response != nil:
+			resp = m.response
+		}
+		for _, onSend := range c.onSend {
+			onSend(req, resp)
+		}
+	}
+
+	// From here on, if we fail to send this, then we need to remove
+	// this from the pending map so we don't block on it or pile up
+	// pending entries for unsent messages.
+	defer func() {
+		if err != nil {
+			if cc != nil {
+				c.mu.Lock()
+				delete(c.pending, id)
+				c.mu.Unlock()
+			}
+		}
+	}()
+
+	if err := c.stream.WriteObject(m); err != nil {
+		return nil, err
+	}
+	return cc, nil
+}
+
+// Call initiates a JSON-RPC call using the specified method and
+// params, and waits for the response. If the response is successful,
+// its result is stored in result (a pointer to a value that can be
+// JSON-unmarshaled into); otherwise, a non-nil error is returned.
+func (c *Conn) Call(ctx context.Context, method string, params, result interface{}, opts ...CallOption) error {
+	req := &Request{Method: method}
+	if err := req.SetParams(params); err != nil {
+		return err
+	}
+	for _, opt := range opts {
+		if opt == nil {
+			continue
+		}
+		if err := opt.apply(req); err != nil {
+			return err
+		}
+	}
+	call, err := c.send(ctx, &anyMessage{request: req}, true)
+	if err != nil {
+		return err
+	}
+	select {
+	case err, ok := <-call.done:
+		if !ok {
+			err = ErrClosed
+		}
+		if err != nil {
+			return err
+		}
+		if result != nil {
+			if call.response.Result == nil {
+				call.response.Result = &jsonNull
+			}
+			if err := json.Unmarshal(*call.response.Result, result); err != nil {
+				return err
+			}
+		}
+		return nil
+
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+}
+
+var jsonNull = json.RawMessage("null")
+
+// Notify is like Call, but it returns when the notification request
+// is sent (without waiting for a response, because JSON-RPC
+// notifications do not have responses).
+func (c *Conn) Notify(ctx context.Context, method string, params interface{}, opts ...CallOption) error {
+	req := &Request{Method: method, Notif: true}
+	if err := req.SetParams(params); err != nil {
+		return err
+	}
+	for _, opt := range opts {
+		if opt == nil {
+			continue
+		}
+		if err := opt.apply(req); err != nil {
+			return err
+		}
+	}
+	_, err := c.send(ctx, &anyMessage{request: req}, false)
+	return err
+}
+
+// Reply sends a successful response with a result.
+func (c *Conn) Reply(ctx context.Context, id ID, result interface{}) error {
+	resp := &Response{ID: id}
+	if err := resp.SetResult(result); err != nil {
+		return err
+	}
+	_, err := c.send(ctx, &anyMessage{response: resp}, false)
+	return err
+}
+
+// ReplyWithError sends a response with an error.
+func (c *Conn) ReplyWithError(ctx context.Context, id ID, respErr *Error) error {
+	_, err := c.send(ctx, &anyMessage{response: &Response{ID: id, Error: respErr}}, false)
+	return err
+}
+
+// SendResponse sends resp to the peer. It is lower level than (*Conn).Reply.
+func (c *Conn) SendResponse(ctx context.Context, resp *Response) error {
+	_, err := c.send(ctx, &anyMessage{response: resp}, false)
+	return err
+}
+
+// DisconnectNotify returns a channel that is closed when the
+// underlying connection is disconnected.
+func (c *Conn) DisconnectNotify() <-chan struct{} {
+	return c.disconnect
+}
+
+func (c *Conn) readMessages(ctx context.Context) {
+	var err error
+	for err == nil {
+		var m anyMessage
+		err = c.stream.ReadObject(&m)
+		if err != nil {
+			break
+		}
+
+		switch {
+		case m.request != nil:
+			for _, onRecv := range c.onRecv {
+				onRecv(m.request, nil)
+			}
+			c.h.Handle(ctx, c, m.request)
+
+		case m.response != nil:
+			resp := m.response
+			if resp != nil {
+				id := resp.ID
+				c.mu.Lock()
+				call := c.pending[id]
+				delete(c.pending, id)
+				c.mu.Unlock()
+
+				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)
+				}
+			}
+		}
+	}
+
+	c.sending.Lock()
+	c.mu.Lock()
+	c.shutdown = true
+	closing := c.closing
+	if err == io.EOF {
+		if closing {
+			err = ErrClosed
+		} else {
+			err = io.ErrUnexpectedEOF
+		}
+	}
+	for _, call := range c.pending {
+		call.done <- err
+		close(call.done)
+	}
+	c.mu.Unlock()
+	c.sending.Unlock()
+	if err != io.ErrUnexpectedEOF && !closing {
+		c.logger.Printf("jsonrpc2: protocol error: %v\n", err)
+	}
+	close(c.disconnect)
+}
+
+// call represents a JSON-RPC call over its entire lifecycle.
+type call struct {
+	request  *Request
+	response *Response
+	seq      uint64 // the seq of the request
+	done     chan error
+}
+
+// anyMessage represents either a JSON Request or Response.
+type anyMessage struct {
+	request  *Request
+	response *Response
+}
+
+func (m anyMessage) MarshalJSON() ([]byte, error) {
+	var v interface{}
+	switch {
+	case m.request != nil && m.response == nil:
+		v = m.request
+	case m.request == nil && m.response != nil:
+		v = m.response
+	}
+	if v != nil {
+		return json.Marshal(v)
+	}
+	return nil, errors.New("jsonrpc2: message must have exactly one of the request or response fields set")
+}
+
+func (m *anyMessage) UnmarshalJSON(data []byte) error {
+	// The presence of these fields distinguishes between the 2
+	// message types.
+	type msg struct {
+		ID     interface{}              `json:"id"`
+		Method *string                  `json:"method"`
+		Result anyValueWithExplicitNull `json:"result"`
+		Error  interface{}              `json:"error"`
+	}
+
+	var isRequest, isResponse bool
+	checkType := func(m *msg) error {
+		mIsRequest := m.Method != nil
+		mIsResponse := m.Result.null || m.Result.value != nil || m.Error != nil
+		if (!mIsRequest && !mIsResponse) || (mIsRequest && mIsResponse) {
+			return errors.New("jsonrpc2: unable to determine message type (request or response)")
+		}
+		if (mIsRequest && isResponse) || (mIsResponse && isRequest) {
+			return errors.New("jsonrpc2: batch message type mismatch (must be all requests or all responses)")
+		}
+		isRequest = mIsRequest
+		isResponse = mIsResponse
+		return nil
+	}
+
+	if isArray := len(data) > 0 && data[0] == '['; isArray {
+		var msgs []msg
+		if err := json.Unmarshal(data, &msgs); err != nil {
+			return err
+		}
+		if len(msgs) == 0 {
+			return errors.New("jsonrpc2: invalid empty batch")
+		}
+		for i := range msgs {
+			if err := checkType(&msg{
+				ID:     msgs[i].ID,
+				Method: msgs[i].Method,
+				Result: msgs[i].Result,
+				Error:  msgs[i].Error,
+			}); err != nil {
+				return err
+			}
+		}
+	} else {
+		var m msg
+		if err := json.Unmarshal(data, &m); err != nil {
+			return err
+		}
+		if err := checkType(&m); err != nil {
+			return err
+		}
+	}
+
+	var v interface{}
+	switch {
+	case isRequest && !isResponse:
+		v = &m.request
+	case !isRequest && isResponse:
+		v = &m.response
+	}
+	if err := json.Unmarshal(data, v); err != nil {
+		return err
+	}
+	if !isRequest && isResponse && m.response.Error == nil && m.response.Result == nil {
+		m.response.Result = &jsonNull
+	}
+	return nil
+}
+
+// anyValueWithExplicitNull is used to distinguish {} from
+// {"result":null} by anyMessage's JSON unmarshaler.
+type anyValueWithExplicitNull struct {
+	null  bool // JSON "null"
+	value interface{}
+}
+
+func (v anyValueWithExplicitNull) MarshalJSON() ([]byte, error) {
+	return json.Marshal(v.value)
+}
+
+func (v *anyValueWithExplicitNull) UnmarshalJSON(data []byte) error {
+	data = bytes.TrimSpace(data)
+	if string(data) == "null" {
+		*v = anyValueWithExplicitNull{null: true}
+		return nil
+	}
+	*v = anyValueWithExplicitNull{}
+	return json.Unmarshal(data, &v.value)
+}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/jsonrpc2_test.go

@@ -0,0 +1,422 @@
+package jsonrpc2_test
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/gorilla/websocket"
+	"github.com/sourcegraph/jsonrpc2"
+	websocketjsonrpc2 "github.com/sourcegraph/jsonrpc2/websocket"
+)
+
+func TestRequest_MarshalJSON_jsonrpc(t *testing.T) {
+	b, err := json.Marshal(&jsonrpc2.Request{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if want := `{"method":"","id":0,"jsonrpc":"2.0"}`; string(b) != want {
+		t.Errorf("got %q, want %q", b, want)
+	}
+}
+
+func TestResponse_MarshalJSON_jsonrpc(t *testing.T) {
+	null := json.RawMessage("null")
+	b, err := json.Marshal(&jsonrpc2.Response{Result: &null})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if want := `{"id":0,"result":null,"jsonrpc":"2.0"}`; string(b) != want {
+		t.Errorf("got %q, want %q", b, want)
+	}
+}
+
+func TestResponseMarshalJSON_Notif(t *testing.T) {
+	tests := map[*jsonrpc2.Request]bool{
+		{ID: jsonrpc2.ID{Num: 0}}:                   true,
+		{ID: jsonrpc2.ID{Num: 1}}:                   true,
+		{ID: jsonrpc2.ID{Str: "", IsString: true}}:  true,
+		{ID: jsonrpc2.ID{Str: "a", IsString: true}}: true,
+		{Notif: true}: false,
+	}
+	for r, wantIDKey := range tests {
+		b, err := json.Marshal(r)
+		if err != nil {
+			t.Fatal(err)
+		}
+		hasIDKey := bytes.Contains(b, []byte(`"id"`))
+		if hasIDKey != wantIDKey {
+			t.Errorf("got %s, want contain id key: %v", b, wantIDKey)
+		}
+	}
+}
+
+func TestResponseUnmarshalJSON_Notif(t *testing.T) {
+	tests := map[string]bool{
+		`{"method":"f","id":0}`:   false,
+		`{"method":"f","id":1}`:   false,
+		`{"method":"f","id":"a"}`: false,
+		`{"method":"f","id":""}`:  false,
+		`{"method":"f"}`:          true,
+	}
+	for s, want := range tests {
+		var r jsonrpc2.Request
+		if err := json.Unmarshal([]byte(s), &r); err != nil {
+			t.Fatal(err)
+		}
+		if r.Notif != want {
+			t.Errorf("%s: got %v, want %v", s, r.Notif, want)
+		}
+	}
+}
+
+// testHandlerA is the "server" handler.
+type testHandlerA struct{ t *testing.T }
+
+func (h *testHandlerA) Handle(ctx context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) {
+	if req.Notif {
+		return // notification
+	}
+	if err := conn.Reply(ctx, req.ID, fmt.Sprintf("hello, #%s: %s", req.ID, *req.Params)); err != nil {
+		h.t.Error(err)
+	}
+
+	if err := conn.Notify(ctx, "m", fmt.Sprintf("notif for #%s", req.ID)); err != nil {
+		h.t.Error(err)
+	}
+}
+
+// testHandlerB is the "client" handler.
+type testHandlerB struct {
+	t   *testing.T
+	mu  sync.Mutex
+	got []string
+}
+
+func (h *testHandlerB) Handle(ctx context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) {
+	if req.Notif {
+		h.mu.Lock()
+		defer h.mu.Unlock()
+		h.got = append(h.got, string(*req.Params))
+		return
+	}
+	h.t.Errorf("testHandlerB got unexpected request %+v", req)
+}
+
+func TestClientServer(t *testing.T) {
+	t.Run("tcp", func(t *testing.T) {
+		ctx := context.Background()
+		done := make(chan struct{})
+
+		lis, err := net.Listen("tcp", "127.0.0.1:0") // any available address
+		if err != nil {
+			t.Fatal("Listen:", err)
+		}
+		defer func() {
+			if lis == nil {
+				return // already closed
+			}
+			if err = lis.Close(); err != nil {
+				if !strings.HasSuffix(err.Error(), "use of closed network connection") {
+					t.Fatal(err)
+				}
+			}
+		}()
+
+		ha := testHandlerA{t: t}
+		go func() {
+			if err = serve(ctx, lis, &ha); err != nil {
+				if !strings.HasSuffix(err.Error(), "use of closed network connection") {
+					t.Error(err)
+				}
+			}
+			close(done)
+		}()
+
+		conn, err := net.Dial("tcp", lis.Addr().String())
+		if err != nil {
+			t.Fatal("Dial:", err)
+		}
+		testClientServer(ctx, t, jsonrpc2.NewBufferedStream(conn, jsonrpc2.VarintObjectCodec{}))
+
+		lis.Close()
+		<-done // ensure Serve's error return (if any) is caught by this test
+	})
+	t.Run("websocket", func(t *testing.T) {
+		ctx := context.Background()
+		done := make(chan struct{})
+
+		ha := testHandlerA{t: t}
+		upgrader := websocket.Upgrader{ReadBufferSize: 1024, WriteBufferSize: 1024}
+		s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			c, err := upgrader.Upgrade(w, r, nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer c.Close()
+			jc := jsonrpc2.NewConn(r.Context(), websocketjsonrpc2.NewObjectStream(c), &ha)
+			<-jc.DisconnectNotify()
+			close(done)
+		}))
+		defer s.Close()
+
+		c, resp, err := websocket.DefaultDialer.Dial(strings.Replace(s.URL, "http:", "ws:", 1), nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer resp.Body.Close()
+		defer c.Close()
+		testClientServer(ctx, t, websocketjsonrpc2.NewObjectStream(c))
+
+		<-done // keep the test running until the WebSocket disconnects (to avoid missing errors)
+	})
+}
+
+func testClientServer(ctx context.Context, t *testing.T, stream jsonrpc2.ObjectStream) {
+	hb := testHandlerB{t: t}
+	cc := jsonrpc2.NewConn(ctx, stream, &hb)
+	defer func() {
+		if err := cc.Close(); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// Simple
+	const n = 100
+	for i := 0; i < n; i++ {
+		var got string
+		if err := cc.Call(ctx, "f", []int32{1, 2, 3}, &got); err != nil {
+			t.Fatal(err)
+		}
+		if want := fmt.Sprintf("hello, #%d: [1,2,3]", i); got != want {
+			t.Errorf("got result %q, want %q", got, want)
+		}
+	}
+	time.Sleep(100 * time.Millisecond)
+	hb.mu.Lock()
+	got := hb.got
+	hb.mu.Unlock()
+	if len(got) != n {
+		t.Errorf("testHandlerB got %d notifications, want %d", len(hb.got), n)
+	}
+	// Ensure messages are in order since we are not using the async handler.
+	for i, s := range got {
+		want := fmt.Sprintf(`"notif for #%d"`, i)
+		if s != want {
+			t.Fatalf("out of order response. got %q, want %q", s, want)
+		}
+	}
+}
+
+func inMemoryPeerConns() (io.ReadWriteCloser, io.ReadWriteCloser) {
+	sr, cw := io.Pipe()
+	cr, sw := io.Pipe()
+	return &pipeReadWriteCloser{sr, sw}, &pipeReadWriteCloser{cr, cw}
+}
+
+type pipeReadWriteCloser struct {
+	*io.PipeReader
+	*io.PipeWriter
+}
+
+func (c *pipeReadWriteCloser) Close() error {
+	err1 := c.PipeReader.Close()
+	err2 := c.PipeWriter.Close()
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+type handlerFunc func(context.Context, *jsonrpc2.Conn, *jsonrpc2.Request)
+
+func (h handlerFunc) Handle(ctx context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) {
+	h(ctx, conn, req)
+}
+
+func TestPickID(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	a, b := inMemoryPeerConns()
+	defer a.Close()
+	defer b.Close()
+
+	handler := handlerFunc(func(ctx context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) {
+		if err := conn.Reply(ctx, req.ID, fmt.Sprintf("hello, #%s: %s", req.ID, *req.Params)); err != nil {
+			t.Error(err)
+		}
+	})
+	connA := jsonrpc2.NewConn(ctx, jsonrpc2.NewBufferedStream(a, jsonrpc2.VSCodeObjectCodec{}), handler)
+	connB := jsonrpc2.NewConn(ctx, jsonrpc2.NewBufferedStream(b, jsonrpc2.VSCodeObjectCodec{}), noopHandler{})
+	defer connA.Close()
+	defer connB.Close()
+
+	const n = 100
+	for i := 0; i < n; i++ {
+		var opts []jsonrpc2.CallOption
+		id := jsonrpc2.ID{Num: uint64(i)}
+
+		// This is the actual test, every 3rd request we specify the
+		// ID and ensure we get a response with the correct ID echoed
+		// back
+		if i%3 == 0 {
+			id = jsonrpc2.ID{
+				Str:      fmt.Sprintf("helloworld-%d", i/3),
+				IsString: true,
+			}
+			opts = append(opts, jsonrpc2.PickID(id))
+		}
+
+		var got string
+		if err := connB.Call(ctx, "f", []int32{1, 2, 3}, &got, opts...); err != nil {
+			t.Fatal(err)
+		}
+		if want := fmt.Sprintf("hello, #%s: [1,2,3]", id); got != want {
+			t.Errorf("got result %q, want %q", got, want)
+		}
+	}
+}
+
+func TestHandlerBlocking(t *testing.T) {
+	// We send N notifications with an increasing parameter. Since the
+	// handler is blocking, we expect to process the notifications in the
+	// order they are sent.
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	a, b := inMemoryPeerConns()
+	defer a.Close()
+	defer b.Close()
+	var (
+		wg     sync.WaitGroup
+		params []int
+	)
+	handler := handlerFunc(func(ctx context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) {
+		var i int
+		_ = json.Unmarshal(*req.Params, &i)
+		// don't need to synchronize access to ids since we should be blocking
+		params = append(params, i)
+		wg.Done()
+	})
+	connA := jsonrpc2.NewConn(ctx, jsonrpc2.NewBufferedStream(a, jsonrpc2.VSCodeObjectCodec{}), handler)
+	connB := jsonrpc2.NewConn(ctx, jsonrpc2.NewBufferedStream(b, jsonrpc2.VSCodeObjectCodec{}), noopHandler{})
+	defer connA.Close()
+	defer connB.Close()
+
+	const n = 100
+	for i := 0; i < n; i++ {
+		wg.Add(1)
+		if err := connB.Notify(ctx, "f", i); err != nil {
+			t.Fatal(err)
+		}
+	}
+	wg.Wait()
+	if len(params) < n {
+		t.Fatalf("want %d params, got %d", n, len(params))
+	}
+	for want, got := range params {
+		if want != got {
+			t.Fatalf("want param %d, got %d", want, got)
+		}
+	}
+}
+
+type noopHandler struct{}
+
+func (noopHandler) Handle(ctx context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) {}
+
+type readWriteCloser struct {
+	read, write func(p []byte) (n int, err error)
+}
+
+func (x readWriteCloser) Read(p []byte) (n int, err error) {
+	return x.read(p)
+}
+
+func (x readWriteCloser) Write(p []byte) (n int, err error) {
+	return x.write(p)
+}
+
+func (readWriteCloser) Close() error { return nil }
+
+func eof(p []byte) (n int, err error) {
+	return 0, io.EOF
+}
+
+func TestConn_DisconnectNotify_EOF(t *testing.T) {
+	c := jsonrpc2.NewConn(context.Background(), jsonrpc2.NewBufferedStream(&readWriteCloser{eof, eof}, jsonrpc2.VarintObjectCodec{}), nil)
+	select {
+	case <-c.DisconnectNotify():
+	case <-time.After(200 * time.Millisecond):
+		t.Fatal("no disconnect notification")
+	}
+}
+
+func TestConn_DisconnectNotify_Close(t *testing.T) {
+	c := jsonrpc2.NewConn(context.Background(), jsonrpc2.NewBufferedStream(&readWriteCloser{eof, eof}, jsonrpc2.VarintObjectCodec{}), nil)
+	if err := c.Close(); err != nil {
+		t.Error(err)
+	}
+	select {
+	case <-c.DisconnectNotify():
+	case <-time.After(200 * time.Millisecond):
+		t.Fatal("no disconnect notification")
+	}
+}
+
+func TestConn_DisconnectNotify_Close_async(t *testing.T) {
+	done := make(chan struct{})
+	c := jsonrpc2.NewConn(context.Background(), jsonrpc2.NewBufferedStream(&readWriteCloser{eof, eof}, jsonrpc2.VarintObjectCodec{}), nil)
+	go func() {
+		if err := c.Close(); err != nil && err != jsonrpc2.ErrClosed {
+			t.Error(err)
+		}
+		close(done)
+	}()
+	select {
+	case <-c.DisconnectNotify():
+	case <-time.After(200 * time.Millisecond):
+		t.Fatal("no disconnect notification")
+	}
+	<-done
+}
+
+func TestConn_Close_waitingForResponse(t *testing.T) {
+	c := jsonrpc2.NewConn(context.Background(), jsonrpc2.NewBufferedStream(&readWriteCloser{eof, eof}, jsonrpc2.VarintObjectCodec{}), noopHandler{})
+	done := make(chan struct{})
+	go func() {
+		if err := c.Call(context.Background(), "m", nil, nil); err != jsonrpc2.ErrClosed {
+			t.Errorf("got error %v, want %v", err, jsonrpc2.ErrClosed)
+		}
+		close(done)
+	}()
+	if err := c.Close(); err != nil && err != jsonrpc2.ErrClosed {
+		t.Error(err)
+	}
+	select {
+	case <-c.DisconnectNotify():
+	case <-time.After(200 * time.Millisecond):
+		t.Fatal("no disconnect notification")
+	}
+	<-done
+}
+
+func serve(ctx context.Context, lis net.Listener, h jsonrpc2.Handler, opts ...jsonrpc2.ConnOpt) error {
+	for {
+		conn, err := lis.Accept()
+		if err != nil {
+			return err
+		}
+		jsonrpc2.NewConn(ctx, jsonrpc2.NewBufferedStream(conn, jsonrpc2.VarintObjectCodec{}), h, opts...)
+	}
+}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/object_test.go

@@ -0,0 +1,128 @@
+package jsonrpc2
+
+import (
+	"bytes"
+	"encoding/json"
+	"reflect"
+	"testing"
+)
+
+func TestAnyMessage(t *testing.T) {
+	tests := map[string]struct {
+		request, response, invalid bool
+	}{
+		// Single messages
+		`{}`:                                   {invalid: true},
+		`{"foo":"bar"}`:                        {invalid: true},
+		`{"method":"m"}`:                       {request: true},
+		`{"result":123}`:                       {response: true},
+		`{"result":null}`:                      {response: true},
+		`{"error":{"code":456,"message":"m"}}`: {response: true},
+	}
+	for s, want := range tests {
+		var m anyMessage
+		if err := json.Unmarshal([]byte(s), &m); err != nil {
+			if !want.invalid {
+				t.Errorf("%s: error: %v", s, err)
+			}
+			continue
+		}
+		if (m.request != nil) != want.request {
+			t.Errorf("%s: got request %v, want %v", s, m.request != nil, want.request)
+		}
+		if (m.response != nil) != want.response {
+			t.Errorf("%s: got response %v, want %v", s, m.response != nil, want.response)
+		}
+	}
+}
+
+func TestRequest_MarshalUnmarshalJSON(t *testing.T) {
+	null := json.RawMessage("null")
+	obj := json.RawMessage(`{"foo":"bar"}`)
+	tests := []struct {
+		data []byte
+		want Request
+	}{
+		{
+			data: []byte(`{"method":"m","params":{"foo":"bar"},"id":123,"jsonrpc":"2.0"}`),
+			want: Request{ID: ID{Num: 123}, Method: "m", Params: &obj},
+		},
+		{
+			data: []byte(`{"method":"m","params":null,"id":123,"jsonrpc":"2.0"}`),
+			want: Request{ID: ID{Num: 123}, Method: "m", Params: &null},
+		},
+		{
+			data: []byte(`{"method":"m","id":123,"jsonrpc":"2.0"}`),
+			want: Request{ID: ID{Num: 123}, Method: "m", Params: nil},
+		},
+	}
+	for _, test := range tests {
+		var got Request
+		if err := json.Unmarshal(test.data, &got); err != nil {
+			t.Error(err)
+			continue
+		}
+		if !reflect.DeepEqual(got, test.want) {
+			t.Errorf("%q: got %+v, want %+v", test.data, got, test.want)
+			continue
+		}
+		data, err := json.Marshal(got)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		if !bytes.Equal(data, test.data) {
+			t.Errorf("got JSON %q, want %q", data, test.data)
+		}
+	}
+}
+
+func TestResponse_MarshalUnmarshalJSON(t *testing.T) {
+	null := json.RawMessage("null")
+	obj := json.RawMessage(`{"foo":"bar"}`)
+	tests := []struct {
+		data  []byte
+		want  Response
+		error bool
+	}{
+		{
+			data: []byte(`{"id":123,"result":{"foo":"bar"},"jsonrpc":"2.0"}`),
+			want: Response{ID: ID{Num: 123}, Result: &obj},
+		},
+		{
+			data: []byte(`{"id":123,"result":null,"jsonrpc":"2.0"}`),
+			want: Response{ID: ID{Num: 123}, Result: &null},
+		},
+		{
+			data:  []byte(`{"id":123,"jsonrpc":"2.0"}`),
+			want:  Response{ID: ID{Num: 123}, Result: nil},
+			error: true, // either result or error field must be set
+		},
+	}
+	for _, test := range tests {
+		var got Response
+		if err := json.Unmarshal(test.data, &got); err != nil {
+			t.Error(err)
+			continue
+		}
+		if !reflect.DeepEqual(got, test.want) {
+			t.Errorf("%q: got %+v, want %+v", test.data, got, test.want)
+			continue
+		}
+		data, err := json.Marshal(got)
+		if err != nil {
+			if test.error {
+				continue
+			}
+			t.Error(err)
+			continue
+		}
+		if test.error {
+			t.Errorf("%q: expected error", test.data)
+			continue
+		}
+		if !bytes.Equal(data, test.data) {
+			t.Errorf("got JSON %q, want %q", data, test.data)
+		}
+	}
+}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/stream.go

@@ -0,0 +1,164 @@
+package jsonrpc2
+
+import (
+	"bufio"
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+// An ObjectStream is a bidirectional stream of JSON-RPC 2.0 objects.
+type ObjectStream interface {
+	// WriteObject writes a JSON-RPC 2.0 object to the stream.
+	WriteObject(obj interface{}) error
+
+	// ReadObject reads the next JSON-RPC 2.0 object from the stream
+	// and stores it in the value pointed to by v.
+	ReadObject(v interface{}) error
+
+	io.Closer
+}
+
+// A bufferedObjectStream is an ObjectStream that uses a buffered
+// io.ReadWriteCloser to send and receive objects.
+type bufferedObjectStream struct {
+	conn io.Closer // all writes should go through w, all reads through r
+	w    *bufio.Writer
+	r    *bufio.Reader
+
+	codec ObjectCodec
+
+	mu sync.Mutex
+}
+
+// NewBufferedStream creates a buffered stream from a network
+// connection (or other similar interface). The underlying
+// objectStream is used to produce the bytes to write to the stream
+// for the JSON-RPC 2.0 objects.
+func NewBufferedStream(conn io.ReadWriteCloser, codec ObjectCodec) ObjectStream {
+	return &bufferedObjectStream{
+		conn:  conn,
+		w:     bufio.NewWriter(conn),
+		r:     bufio.NewReader(conn),
+		codec: codec,
+	}
+}
+
+// WriteObject implements ObjectStream.
+func (t *bufferedObjectStream) WriteObject(obj interface{}) error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if err := t.codec.WriteObject(t.w, obj); err != nil {
+		return err
+	}
+	return t.w.Flush()
+}
+
+// ReadObject implements ObjectStream.
+func (t *bufferedObjectStream) ReadObject(v interface{}) error {
+	return t.codec.ReadObject(t.r, v)
+}
+
+// Close implements ObjectStream.
+func (t *bufferedObjectStream) Close() error {
+	return t.conn.Close()
+}
+
+// An ObjectCodec specifies how to encoed and decode a JSON-RPC 2.0
+// object in a stream.
+type ObjectCodec interface {
+	// WriteObject writes a JSON-RPC 2.0 object to the stream.
+	WriteObject(stream io.Writer, obj interface{}) error
+
+	// ReadObject reads the next JSON-RPC 2.0 object from the stream
+	// and stores it in the value pointed to by v.
+	ReadObject(stream *bufio.Reader, v interface{}) error
+}
+
+// VarintObjectCodec reads/writes JSON-RPC 2.0 objects with a varint
+// header that encodes the byte length.
+type VarintObjectCodec struct{}
+
+// WriteObject implements ObjectCodec.
+func (VarintObjectCodec) WriteObject(stream io.Writer, obj interface{}) error {
+	data, err := json.Marshal(obj)
+	if err != nil {
+		return err
+	}
+	var buf [binary.MaxVarintLen64]byte
+	b := binary.PutUvarint(buf[:], uint64(len(data)))
+	if _, err := stream.Write(buf[:b]); err != nil {
+		return err
+	}
+	if _, err := stream.Write(data); err != nil {
+		return err
+	}
+	return nil
+}
+
+// ReadObject implements ObjectCodec.
+func (VarintObjectCodec) ReadObject(stream *bufio.Reader, v interface{}) error {
+	b, err := binary.ReadUvarint(stream)
+	if err != nil {
+		return err
+	}
+	return json.NewDecoder(io.LimitReader(stream, int64(b))).Decode(v)
+}
+
+// VSCodeObjectCodec reads/writes JSON-RPC 2.0 objects with
+// Content-Length and Content-Type headers, as specified by
+// https://github.com/Microsoft/language-server-protocol/blob/master/protocol.md#base-protocol.
+type VSCodeObjectCodec struct{}
+
+// WriteObject implements ObjectCodec.
+func (VSCodeObjectCodec) WriteObject(stream io.Writer, obj interface{}) error {
+	data, err := json.Marshal(obj)
+	if err != nil {
+		return err
+	}
+	if _, err := fmt.Fprintf(stream, "Content-Length: %d\r\n\r\n", len(data)); err != nil {
+		return err
+	}
+	if _, err := stream.Write(data); err != nil {
+		return err
+	}
+	return nil
+}
+
+// ReadObject implements ObjectCodec.
+func (VSCodeObjectCodec) ReadObject(stream *bufio.Reader, v interface{}) error {
+	var contentLength uint64
+	for {
+		line, err := stream.ReadString('\r')
+		if err != nil {
+			return err
+		}
+		b, err := stream.ReadByte()
+		if err != nil {
+			return err
+		}
+		if b != '\n' {
+			return fmt.Errorf(`jsonrpc2: line endings must be \r\n`)
+		}
+		if line == "\r" {
+			break
+		}
+		if strings.HasPrefix(line, "Content-Length: ") {
+			line = strings.TrimPrefix(line, "Content-Length: ")
+			line = strings.TrimSpace(line)
+			var err error
+			contentLength, err = strconv.ParseUint(line, 10, 32)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	if contentLength == 0 {
+		return fmt.Errorf("jsonrpc2: no Content-Length header found")
+	}
+	return json.NewDecoder(io.LimitReader(stream, int64(contentLength))).Decode(v)
+}

go/pkg/mod/github.com/sourcegraph/jsonrpc2@v0.0.0-20191222043438-96c4efab7ee2/websocket/stream.go

@@ -0,0 +1,44 @@
+// Package websocket provides WebSocket transport support for JSON-RPC
+// 2.0.
+package websocket
+
+import (
+	"io"
+
+	ws "github.com/gorilla/websocket"
+)
+
+// A ObjectStream is a jsonrpc2.ObjectStream that uses a WebSocket to
+// send and receive JSON-RPC 2.0 objects.
+type ObjectStream struct {
+	conn *ws.Conn
+}
+
+// NewObjectStream creates a new jsonrpc2.ObjectStream for sending and
+// receiving JSON-RPC 2.0 objects over a WebSocket.
+func NewObjectStream(conn *ws.Conn) ObjectStream {
+	return ObjectStream{conn: conn}
+}
+
+// WriteObject implements jsonrpc2.ObjectStream.
+func (t ObjectStream) WriteObject(obj interface{}) error {
+	return t.conn.WriteJSON(obj)
+}
+
+// ReadObject implements jsonrpc2.ObjectStream.
+func (t ObjectStream) ReadObject(v interface{}) error {
+	err := t.conn.ReadJSON(v)
+	if e, ok := err.(*ws.CloseError); ok {
+		if e.Code == ws.CloseAbnormalClosure && e.Text == io.ErrUnexpectedEOF.Error() {
+			// Suppress a noisy (but harmless) log message by
+			// unwrapping this error.
+			err = io.ErrUnexpectedEOF
+		}
+	}
+	return err
+}
+
+// Close implements jsonrpc2.ObjectStream.
+func (t ObjectStream) Close() error {
+	return t.conn.Close()
+}