From 4d39b902efd39dbac5c5f1c17c9f534f8572982f Mon Sep 17 00:00:00 2001
From: Sri Kidambi <1702865+kidambisrinivas@users.noreply.github.com>
Date: Tue, 1 Oct 2024 12:11:03 +0100
Subject: [PATCH] Test cursor usage of LogEventTrigger capability

---
 .../capabilities/log_event_trigger_test.go    | 98 ++++++++++++++++---
 1 file changed, 82 insertions(+), 16 deletions(-)

diff --git a/core/services/relay/evm/capabilities/log_event_trigger_test.go b/core/services/relay/evm/capabilities/log_event_trigger_test.go
index f2104529b7f..497b9f91e44 100644
--- a/core/services/relay/evm/capabilities/log_event_trigger_test.go
+++ b/core/services/relay/evm/capabilities/log_event_trigger_test.go
@@ -9,6 +9,7 @@ import (
 	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/require"
 
+	"github.com/smartcontractkit/chainlink-common/pkg/capabilities"
 	"github.com/smartcontractkit/chainlink-common/pkg/services/servicetest"
 	commontypes "github.com/smartcontractkit/chainlink-common/pkg/types"
 	commonmocks "github.com/smartcontractkit/chainlink-common/pkg/types/core/mocks"
@@ -59,31 +60,96 @@ func TestLogEventTriggerEVMHappyPath(t *testing.T) {
 	log1Ch, err := logEventTriggerService.RegisterTrigger(ctx, th.LogEmitterRegRequest)
 	require.NoError(t, err)
 
-	expectedLogVal := int64(10)
+	emitLogTxnAndWaitForLog(t, th, log1Ch, []*big.Int{big.NewInt(10)})
+}
+
+// Test if Log Event Trigger Capability is able to receive only new logs
+// by using cursor and does not receive duplicate logs
+func TestLogEventTriggerCursorNewLogs(t *testing.T) {
+	th := testutils.NewContractReaderTH(t)
+
+	logEventConfig := logevent.Config{
+		ChainID:        th.BackendTH.ChainID.String(),
+		Network:        "evm",
+		LookbackBlocks: 1000,
+		PollPeriod:     1000,
+	}
+
+	// Create a new contract reader to return from mock relayer
+	ctx := coretestutils.Context(t)
+
+	// Fetch latest head from simulated backend to return from mock relayer
+	height, err := th.BackendTH.EVMClient.LatestBlockHeight(ctx)
+	require.NoError(t, err)
+	block, err := th.BackendTH.EVMClient.BlockByNumber(ctx, height)
+	require.NoError(t, err)
+
+	// Mock relayer to return a New ContractReader instead of gRPC client of a ContractReader
+	relayer := commonmocks.NewRelayer(t)
+	relayer.On("NewContractReader", mock.Anything, th.LogEmitterContractReaderCfg).Return(th.LogEmitterContractReader, nil).Once()
+	relayer.On("LatestHead", mock.Anything).Return(commontypes.Head{
+		Height:    height.String(),
+		Hash:      block.Hash().Bytes(),
+		Timestamp: block.Time(),
+	}, nil).Once()
+
+	// Create Log Event Trigger Service and register trigger
+	logEventTriggerService, err := logevent.NewTriggerService(ctx,
+		th.BackendTH.Lggr,
+		relayer,
+		logEventConfig)
+	require.NoError(t, err)
+
+	// Start the service
+	servicetest.Run(t, logEventTriggerService)
+
+	log1Ch, err := logEventTriggerService.RegisterTrigger(ctx, th.LogEmitterRegRequest)
+	require.NoError(t, err)
 
-	// Send a blockchain transaction that emits logs
+	emitLogTxnAndWaitForLog(t, th, log1Ch, []*big.Int{big.NewInt(10)})
+
+	// This confirms that the cursor being tracked by log event trigger capability
+	// works correctly and does not send old logs again as duplicates to the
+	// callback channel log1Ch
+	emitLogTxnAndWaitForLog(t, th, log1Ch, []*big.Int{big.NewInt(11), big.NewInt(12)})
+}
+
+// Send a transaction to EmitLog contract to emit Log1 events with given
+// input parameters and wait for those logs to be received from relayer
+// and ContractReader's QueryKey APIs used by Log Event Trigger
+func emitLogTxnAndWaitForLog(t *testing.T,
+	th *testutils.ContractReaderTH,
+	log1Ch <-chan capabilities.TriggerResponse,
+	expectedLogVals []*big.Int) {
 	done := make(chan struct{})
-	t.Cleanup(func() { <-done })
+	var err error
 	go func() {
 		defer close(done)
 		_, err =
-			th.LogEmitterContract.EmitLog1(th.BackendTH.ContractsOwner, []*big.Int{big.NewInt(expectedLogVal)})
+			th.LogEmitterContract.EmitLog1(th.BackendTH.ContractsOwner, expectedLogVals)
 		assert.NoError(t, err)
 		th.BackendTH.Backend.Commit()
 		th.BackendTH.Backend.Commit()
 		th.BackendTH.Backend.Commit()
 	}()
 
-	// Wait for logs with a timeout
-	_, output, err := testutils.WaitForLog(th.BackendTH.Lggr, log1Ch, 15*time.Second)
-	require.NoError(t, err)
-	th.BackendTH.Lggr.Infow("EmitLog", "output", output)
-	// Verify if valid cursor is returned
-	cursor, err := testutils.GetStrVal(output, "Cursor")
-	require.NoError(t, err)
-	require.True(t, len(cursor) > 60)
-	// Verify if Arg0 is correct
-	actualLogVal, err := testutils.GetBigIntValL2(output, "Data", "Arg0")
-	require.NoError(t, err)
-	require.Equal(t, expectedLogVal, actualLogVal.Int64())
+	for _, expectedLogVal := range expectedLogVals {
+		// Wait for logs with a timeout
+		_, output, err := testutils.WaitForLog(th.BackendTH.Lggr, log1Ch, 15*time.Second)
+		require.NoError(t, err)
+		th.BackendTH.Lggr.Infow("EmitLog", "output", output)
+
+		// Verify if valid cursor is returned
+		cursor, err := testutils.GetStrVal(output, "Cursor")
+		require.NoError(t, err)
+		require.True(t, len(cursor) > 60)
+
+		// Verify if Arg0 is correct
+		actualLogVal, err := testutils.GetBigIntValL2(output, "Data", "Arg0")
+		require.NoError(t, err)
+
+		require.Equal(t, expectedLogVal.Int64(), actualLogVal.Int64())
+	}
+
+	<-done
 }