test: add test.Scheduler (#58)

When simulating execution of core.Consensus by passing packets through golang-channel or real-socket, we need to utilize time.Sleep and time.Now to simulate the required network/proposing latency. It's problematic when we try to test a simulation with long network latency.

Instead, Scheduler would try to execute the event with minimum timestamp, thus time.Sleep is replaced with Scheduler.nextTick, and time.Now is replaced with Event.Time.

Changes:
- Add test.Scheduler.
- Add test.Stopper interface to provide encapsulate different stop conditions for scheduler.
- Add a reference implementation for test.Stopper, it will stop scheduler when all validators confirmed X blocks proposed from themselves.
- Add a test scenario on core.Consensus that all validators are not byzantine.

1 files changed, 90 insertions, 0 deletions

diff --git a/integration_test/non-byzantine_test.go b/integration_test/non-byzantine_test.go
new file mode 100644
index 0000000..111dcd0
--- /dev/null
+++ b/integration_test/non-byzantine_test.go
@@ -0,0 +1,90 @@
+// Copyright 2018 The dexon-consensus-core Authors
+// This file is part of the dexon-consensus-core library.
+//
+// The dexon-consensus-core 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 dexon-consensus-core 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 dexon-consensus-core library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package integration
+
+import (
+	"testing"
+	"time"
+
+	"github.com/dexon-foundation/dexon-consensus-core/blockdb"
+	"github.com/dexon-foundation/dexon-consensus-core/core/test"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
+	"github.com/stretchr/testify/suite"
+)
+
+type NonByzantineTestSuite struct {
+	suite.Suite
+}
+
+func (s *NonByzantineTestSuite) TestNonByzantine() {
+	var (
+		networkLatency = &normalLatencyModel{
+			Sigma: 20,
+			Mean:  250,
+		}
+		proposingLatency = &normalLatencyModel{
+			Sigma: 30,
+			Mean:  500,
+		}
+		apps = make(map[types.ValidatorID]*test.App)
+		dbs  = make(map[types.ValidatorID]blockdb.BlockDatabase)
+		req  = s.Require()
+	)
+
+	gov, err := test.NewGovernance(25, 700)
+	req.Nil(err)
+	now := time.Now().UTC()
+	for vID := range gov.GetValidatorSet() {
+		apps[vID] = test.NewApp()
+
+		db, err := blockdb.NewMemBackedBlockDB()
+		req.Nil(err)
+		dbs[vID] = db
+	}
+	stopper := test.NewStopByConfirmedBlocks(50, apps, dbs)
+	sch := test.NewScheduler(stopper)
+	for vID := range gov.GetValidatorSet() {
+		key, err := gov.GetPrivateKey(vID)
+		req.Nil(err)
+		v := newValidator(
+			apps[vID],
+			gov,
+			dbs[vID],
+			key,
+			vID,
+			networkLatency,
+			proposingLatency)
+		sch.RegisterEventHandler(vID, v)
+		req.Nil(sch.Seed(newProposeBlockEvent(vID, now)))
+	}
+	sch.Run(10)
+	// Check results by comparing test.App instances.
+	for vFrom := range gov.GetValidatorSet() {
+		req.Nil(apps[vFrom].Verify())
+		for vTo := range gov.GetValidatorSet() {
+			if vFrom == vTo {
+				continue
+			}
+			req.Nil(apps[vFrom].Compare(apps[vTo]))
+		}
+	}
+}
+
+func TestNonByzantine(t *testing.T) {
+	suite.Run(t, new(NonByzantineTestSuite))
+}