go-pulse/rpc/subscription_test.go
Felix Lange 245f3146c2
rpc: implement full bi-directional communication (#18471)
New APIs added:

    client.RegisterName(namespace, service) // makes service available to server
    client.Notify(ctx, method, args...)     // sends a notification
    ClientFromContext(ctx)                  // to get a client in handler method

This is essentially a rewrite of the server-side code. JSON-RPC
processing code is now the same on both server and client side. Many
minor issues were fixed in the process and there is a new test suite for
JSON-RPC spec compliance (and non-compliance in some cases).

List of behavior changes:

- Method handlers are now called with a per-request context instead of a
  per-connection context. The context is canceled right after the method
  returns.
- Subscription error channels are always closed when the connection
  ends. There is no need to also wait on the Notifier's Closed channel
  to detect whether the subscription has ended.
- Client now omits "params" instead of sending "params": null when there
  are no arguments to a call. The previous behavior was not compliant
  with the spec. The server still accepts "params": null.
- Floating point numbers are allowed as "id". The spec doesn't allow
  them, but we handle request "id" as json.RawMessage and guarantee that
  the same number will be sent back.
- Logging is improved significantly. There is now a message at DEBUG
  level for each RPC call served.
2019-02-04 13:47:34 +01:00

207 lines
5.9 KiB
Go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package rpc
import (
"encoding/json"
"fmt"
"net"
"strings"
"testing"
"time"
)
func TestNewID(t *testing.T) {
hexchars := "0123456789ABCDEFabcdef"
for i := 0; i < 100; i++ {
id := string(NewID())
if !strings.HasPrefix(id, "0x") {
t.Fatalf("invalid ID prefix, want '0x...', got %s", id)
}
id = id[2:]
if len(id) == 0 || len(id) > 32 {
t.Fatalf("invalid ID length, want len(id) > 0 && len(id) <= 32), got %d", len(id))
}
for i := 0; i < len(id); i++ {
if strings.IndexByte(hexchars, id[i]) == -1 {
t.Fatalf("unexpected byte, want any valid hex char, got %c", id[i])
}
}
}
}
func TestSubscriptions(t *testing.T) {
var (
namespaces = []string{"eth", "shh", "bzz"}
service = &notificationTestService{}
subCount = len(namespaces)
notificationCount = 3
server = NewServer()
clientConn, serverConn = net.Pipe()
out = json.NewEncoder(clientConn)
in = json.NewDecoder(clientConn)
successes = make(chan subConfirmation)
notifications = make(chan subscriptionResult)
errors = make(chan error, subCount*notificationCount+1)
)
// setup and start server
for _, namespace := range namespaces {
if err := server.RegisterName(namespace, service); err != nil {
t.Fatalf("unable to register test service %v", err)
}
}
go server.ServeCodec(NewJSONCodec(serverConn), OptionMethodInvocation|OptionSubscriptions)
defer server.Stop()
// wait for message and write them to the given channels
go waitForMessages(in, successes, notifications, errors)
// create subscriptions one by one
for i, namespace := range namespaces {
request := map[string]interface{}{
"id": i,
"method": fmt.Sprintf("%s_subscribe", namespace),
"version": "2.0",
"params": []interface{}{"someSubscription", notificationCount, i},
}
if err := out.Encode(&request); err != nil {
t.Fatalf("Could not create subscription: %v", err)
}
}
timeout := time.After(30 * time.Second)
subids := make(map[string]string, subCount)
count := make(map[string]int, subCount)
allReceived := func() bool {
done := len(count) == subCount
for _, c := range count {
if c < notificationCount {
done = false
}
}
return done
}
for !allReceived() {
select {
case confirmation := <-successes: // subscription created
subids[namespaces[confirmation.reqid]] = string(confirmation.subid)
case notification := <-notifications:
count[notification.ID]++
case err := <-errors:
t.Fatal(err)
case <-timeout:
for _, namespace := range namespaces {
subid, found := subids[namespace]
if !found {
t.Errorf("subscription for %q not created", namespace)
continue
}
if count, found := count[subid]; !found || count < notificationCount {
t.Errorf("didn't receive all notifications (%d<%d) in time for namespace %q", count, notificationCount, namespace)
}
}
t.Fatal("timed out")
}
}
}
// This test checks that unsubscribing works.
func TestServerUnsubscribe(t *testing.T) {
// Start the server.
server := newTestServer()
service := &notificationTestService{unsubscribed: make(chan string)}
server.RegisterName("nftest2", service)
p1, p2 := net.Pipe()
go server.ServeCodec(NewJSONCodec(p1), OptionMethodInvocation|OptionSubscriptions)
p2.SetDeadline(time.Now().Add(10 * time.Second))
// Subscribe.
p2.Write([]byte(`{"jsonrpc":"2.0","id":1,"method":"nftest2_subscribe","params":["someSubscription",0,10]}`))
// Handle received messages.
resps := make(chan subConfirmation)
notifications := make(chan subscriptionResult)
errors := make(chan error)
go waitForMessages(json.NewDecoder(p2), resps, notifications, errors)
// Receive the subscription ID.
var sub subConfirmation
select {
case sub = <-resps:
case err := <-errors:
t.Fatal(err)
}
// Unsubscribe and check that it is handled on the server side.
p2.Write([]byte(`{"jsonrpc":"2.0","method":"nftest2_unsubscribe","params":["` + sub.subid + `"]}`))
for {
select {
case id := <-service.unsubscribed:
if id != string(sub.subid) {
t.Errorf("wrong subscription ID unsubscribed")
}
return
case err := <-errors:
t.Fatal(err)
case <-notifications:
// drop notifications
}
}
}
type subConfirmation struct {
reqid int
subid ID
}
func waitForMessages(in *json.Decoder, successes chan subConfirmation, notifications chan subscriptionResult, errors chan error) {
for {
var msg jsonrpcMessage
if err := in.Decode(&msg); err != nil {
errors <- fmt.Errorf("decode error: %v", err)
return
}
switch {
case msg.isNotification():
var res subscriptionResult
if err := json.Unmarshal(msg.Params, &res); err != nil {
errors <- fmt.Errorf("invalid subscription result: %v", err)
} else {
notifications <- res
}
case msg.isResponse():
var c subConfirmation
if msg.Error != nil {
errors <- msg.Error
} else if err := json.Unmarshal(msg.Result, &c.subid); err != nil {
errors <- fmt.Errorf("invalid response: %v", err)
} else {
json.Unmarshal(msg.ID, &c.reqid)
successes <- c
}
default:
errors <- fmt.Errorf("unrecognized message: %v", msg)
return
}
}
}