internal/lsp/lsprpc: update binder tests to handle forwarding

Update the new binder tests to run both with a standalone server, and
with a forwarding chain.

Make a few superficial improvements along the way as well.

Change-Id: Icd197698093a3f6149ab58171806b2388ed75b7f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/321134
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>

internal/jsonrpc2/conn.go

@@ -112,6 +112,7 @@ func newConnection(ctx context.Context, rwc io.ReadWriteCloser, binder Binder) (
 	go c.readIncoming(ctx, reader, readToQueue)
 	go c.manageQueue(ctx, options.Preempter, readToQueue, queueToDeliver)
 	go c.deliverMessages(ctx, options.Handler, queueToDeliver)
+
 	// releaseing the writer must be the last thing we do in case any requests
 	// are blocked waiting for the connection to be ready
 	c.writerBox <- options.Framer.Writer(rwc)

internal/jsonrpc2/jsonrpc2.go

@@ -57,11 +57,11 @@ func (f HandlerFunc) Handle(ctx context.Context, req *Request) (interface{}, err
 	return f(ctx, req)
 }
 
-// async is a small helper for things with an asynchronous result that you can
-// wait for.
+// async is a small helper for operations with an asynchronous result that you
+// can wait for.
 type async struct {
-	ready  chan struct{}
-	errBox chan error
+	ready  chan struct{} // signals that the operation has completed
+	errBox chan error    // guards the operation result
 }
 
 func newAsync() *async {

internal/jsonrpc2/jsonrpc2_test.go

@@ -126,7 +126,7 @@ func TestConnectionHeader(t *testing.T) {
 func testConnection(t *testing.T, framer jsonrpc2.Framer) {
 	stacktest.NoLeak(t)
 	ctx := eventtest.NewContext(context.Background(), t)
-	listener, err := jsonrpc2.NetPipe(ctx)
+	listener, err := jsonrpc2.NetPipeListener(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}

internal/jsonrpc2/net.go

@@ -80,11 +80,11 @@ func (n *netDialer) Dial(ctx context.Context) (io.ReadWriteCloser, error) {
 	return n.dialer.DialContext(ctx, n.network, n.address)
 }
 
-// NetPipe returns a new Listener that listens using net.Pipe.
+// NetPipeListener returns a new Listener that listens using net.Pipe.
 // It is only possibly to connect to it using the Dialier returned by the
 // Dialer method, each call to that method will generate a new pipe the other
 // side of which will be returnd from the Accept call.
-func NetPipe(ctx context.Context) (Listener, error) {
+func NetPipeListener(ctx context.Context) (Listener, error) {
 	return &netPiper{
 		done:   make(chan struct{}),
 		dialed: make(chan io.ReadWriteCloser),

internal/jsonrpc2/serve_test.go

@@ -89,7 +89,7 @@ func TestServe(t *testing.T) {
 			return jsonrpc2.NetListener(ctx, "tcp", "localhost:0", jsonrpc2.NetListenOptions{})
 		}},
 		{"pipe", func(ctx context.Context) (jsonrpc2.Listener, error) {
-			return jsonrpc2.NetPipe(ctx)
+			return jsonrpc2.NetPipeListener(ctx)
 		}},
 	}