swarm: network simulation for swarm tests (#769)

* cmd/swarm: minor cli flag text adjustments

* cmd/swarm, swarm/storage, swarm: fix  mingw on windows test issues

* cmd/swarm: support for smoke tests on the production swarm cluster

* cmd/swarm/swarm-smoke: simplify cluster logic as per suggestion

* changed colour of landing page

* landing page reacts to enter keypress

* swarm/api/http: sticky footer for swarm landing page using flex

* swarm/api/http: sticky footer for error pages and fix for multiple choices

* swarm: propagate ctx to internal apis (#754)

* swarm/simnet: add basic node/service functions

* swarm/netsim: add buckets for global state and kademlia health check

* swarm/netsim: Use sync.Map as bucket and provide cleanup function for...

* swarm, swarm/netsim: adjust SwarmNetworkTest

* swarm/netsim: fix tests

* swarm: added visualization option to sim net redesign

* swarm/netsim: support multiple services per node

* swarm/netsim: remove redundant return statement

* swarm/netsim: add comments

* swarm: shutdown HTTP in Simulation.Close

* swarm: sim HTTP server timeout

* swarm/netsim: add more simulation methods and peer events examples

* swarm/netsim: add WaitKademlia example

* swarm/netsim: fix comments

* swarm/netsim: terminate peer events goroutines on simulation done

* swarm, swarm/netsim: naming updates

* swarm/netsim: return not healthy kademlias on WaitTillHealthy

* swarm: fix WaitTillHealthy call in testSwarmNetwork

* swarm/netsim: allow bucket to have any type for a key

* swarm: Added snapshots to new netsim

* swarm/netsim: add more tests for bucket

* swarm/netsim: move http related things into separate files

* swarm/netsim: add AddNodeWithService option

* swarm/netsim: add more tests and Start* methods

* swarm/netsim: add peer events and kademlia tests

* swarm/netsim: fix some tests flakiness

* swarm/netsim: improve random nodes selection, fix TestStartStop* tests

* swarm/netsim: remove time measurement from TestClose to avoid flakiness

* swarm/netsim: builder pattern for netsim HTTP server (#773)

* swarm/netsim: add connect related tests

* swarm/netsim: add comment for TestPeerEvents

* swarm: rename netsim package to network/simulation

1 files changed, 104 insertions, 0 deletions

diff --git a/swarm/network/simulation/events_test.go b/swarm/network/simulation/events_test.go
new file mode 100644
index 000000000..0c185d977
--- /dev/null
+++ b/swarm/network/simulation/events_test.go
@@ -0,0 +1,104 @@
+// Copyright 2018 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 simulation
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+)
+
+// TestPeerEvents creates simulation, adds two nodes,
+// register for peer events, connects nodes in a chain
+// and waits for the number of connection events to
+// be received.
+func TestPeerEvents(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	_, err := sim.AddNodes(2)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	events := sim.PeerEvents(ctx, sim.NodeIDs())
+
+	// two nodes -> two connection events
+	expectedEventCount := 2
+
+	var wg sync.WaitGroup
+	wg.Add(expectedEventCount)
+
+	go func() {
+		for e := range events {
+			if e.Error != nil {
+				if e.Error == context.Canceled {
+					return
+				}
+				t.Error(e.Error)
+				continue
+			}
+			wg.Done()
+		}
+	}()
+
+	err = sim.ConnectNodesChain(sim.NodeIDs())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	wg.Wait()
+}
+
+func TestPeerEventsTimeout(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	_, err := sim.AddNodes(2)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
+	events := sim.PeerEvents(ctx, sim.NodeIDs())
+
+	done := make(chan struct{})
+	go func() {
+		for e := range events {
+			if e.Error == context.Canceled {
+				return
+			}
+			if e.Error == context.DeadlineExceeded {
+				close(done)
+				return
+			} else {
+				t.Fatal(e.Error)
+			}
+		}
+	}()
+
+	select {
+	case <-time.After(time.Second):
+		t.Error("no context deadline received")
+	case <-done:
+		// all good, context deadline detected
+	}
+}