// Copyright 2017 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/>.
/*
the p2p/testing package provides a unit test scheme to check simple
protocol message exchanges with one pivot node and a number of dummy peers
The pivot test node runs a node.Service, the dummy peers run a mock node
that can be used to send and receive messages
*/
package testing
import (
"fmt"
"sync"
"testing"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/node"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/discover"
"github.com/ethereum/go-ethereum/p2p/simulations"
"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
"github.com/ethereum/go-ethereum/rpc"
)
// ProtocolTester is the tester environment used for unit testing protocol
// message exchanges. It uses p2p/simulations framework
type ProtocolTester struct {
*ProtocolSession
network *simulations.Network
}
// NewProtocolTester constructs a new ProtocolTester
// it takes as argument the pivot node id, the number of dummy peers and the
// protocol run function called on a peer connection by the p2p server
func NewProtocolTester(t *testing.T, id discover.NodeID, n int, run func(*p2p.Peer, p2p.MsgReadWriter) error) *ProtocolTester {
services := adapters.Services{
"test": func(ctx *adapters.ServiceContext) (node.Service, error) {
return &testNode{run}, nil
},
"mock": func(ctx *adapters.ServiceContext) (node.Service, error) {
return newMockNode(), nil
},
}
adapter := adapters.NewSimAdapter(services)
net := simulations.NewNetwork(adapter, &simulations.NetworkConfig{})
if _, err := net.NewNodeWithConfig(&adapters.NodeConfig{
ID: id,
EnableMsgEvents: true,
Services: []string{"test"},
}); err != nil {
panic(err.Error())
}
if err := net.Start(id); err != nil {
panic(err.Error())
}
node := net.GetNode(id).Node.(*adapters.SimNode)
peers := make([]*adapters.NodeConfig, n)
peerIDs := make([]discover.NodeID, n)
for i := 0; i < n; i++ {
peers[i] = adapters.RandomNodeConfig()
peers[i].Services = []string{"mock"}
peerIDs[i] = peers[i].ID
}
events := make(chan *p2p.PeerEvent, 1000)
node.SubscribeEvents(events)
ps := &ProtocolSession{
Server: node.Server(),
IDs: peerIDs,
adapter: adapter,
events: events,
}
self := &ProtocolTester{
ProtocolSession: ps,
network: net,
}
self.Connect(id, peers...)
return self
}
// Stop stops the p2p server
func (self *ProtocolTester) Stop() error {
self.Server.Stop()
return nil
}
// Connect brings up the remote peer node and connects it using the
// p2p/simulations network connection with the in memory network adapter
func (self *ProtocolTester) Connect(selfID discover.NodeID, peers ...*adapters.NodeConfig) {
for _, peer := range peers {
log.Trace(fmt.Sprintf("start node %v", peer.ID))
if _, err := self.network.NewNodeWithConfig(peer); err != nil {
panic(fmt.Sprintf("error starting peer %v: %v", peer.ID, err))
}
if err := self.network.Start(peer.ID); err != nil {
panic(fmt.Sprintf("error starting peer %v: %v", peer.ID, err))
}
log.Trace(fmt.Sprintf("connect to %v", peer.ID))
if err := self.network.Connect(selfID, peer.ID); err != nil {
panic(fmt.Sprintf("error connecting to peer %v: %v", peer.ID, err))
}
}
}
// testNode wraps a protocol run function and implements the node.Service
// interface
type testNode struct {
run func(*p2p.Peer, p2p.MsgReadWriter) error
}
func (t *testNode) Protocols() []p2p.Protocol {
return []p2p.Protocol{{
Length: 100,
Run: t.run,
}}
}
func (t *testNode) APIs() []rpc.API {
return nil
}
func (t *testNode) Start(server *p2p.Server) error {
return nil
}
func (t *testNode) Stop() error {
return nil
}
// mockNode is a testNode which doesn't actually run a protocol, instead
// exposing channels so that tests can manually trigger and expect certain
// messages
type mockNode struct {
testNode
trigger chan *Trigger
expect chan *Expect
err chan error
stop chan struct{}
stopOnce sync.Once
}
func newMockNode() *mockNode {
mock := &mockNode{
trigger: make(chan *Trigger),
expect: make(chan *Expect),
err: make(chan error),
stop: make(chan struct{}),
}
mock.testNode.run = mock.Run
return mock
}
// Run is a protocol run function which just loops waiting for tests to
// instruct it to either trigger or expect a message from the peer
func (m *mockNode) Run(peer *p2p.Peer, rw p2p.MsgReadWriter) error {
for {
select {
case trig := <-m.trigger:
m.err <- p2p.Send(rw, trig.Code, trig.Msg)
case exp := <-m.expect:
m.err <- p2p.ExpectMsg(rw, exp.Code, exp.Msg)
case <-m.stop:
return nil
}
}
}
func (m *mockNode) Trigger(trig *Trigger) error {
m.trigger <- trig
return <-m.err
}
func (m *mockNode) Expect(exp *Expect) error {
m.expect <- exp
return <-m.err
}
func (m *mockNode) Stop() error {
m.stopOnce.Do(func() { close(m.stop) })
return nil
}
