diff --git a/internal/workflow_replayer_utils_test.go b/internal/workflow_replayer_utils_test.go
new file mode 100644
index 000000000..3e2386dc3
--- /dev/null
+++ b/internal/workflow_replayer_utils_test.go
@@ -0,0 +1,117 @@
+// Copyright (c) 2017-2021 Uber Technologies Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package internal
+
+import (
+	"github.com/stretchr/testify/assert"
+	"go.uber.org/cadence/.gen/go/shared"
+	"go.uber.org/cadence/internal/common"
+	"testing"
+)
+
+type matchReplayWithHistoryTestCase struct {
+	name            string
+	replayDecisions []*shared.Decision
+	historyEvents   []*shared.HistoryEvent
+	expectError     bool
+}
+
+func TestMatchReplayWithHistory(t *testing.T) {
+	testCases := []matchReplayWithHistoryTestCase{
+		{
+			name: "Success matching",
+			replayDecisions: []*shared.Decision{
+				mockDecision(shared.DecisionTypeScheduleActivityTask),
+			},
+			historyEvents: []*shared.HistoryEvent{
+				mockHistoryEvent(shared.EventTypeActivityTaskScheduled),
+			},
+			expectError: false,
+		},
+		{
+			name: "Mismatch error",
+			replayDecisions: []*shared.Decision{
+				mockDecision(shared.DecisionTypeStartTimer),
+			},
+			historyEvents: []*shared.HistoryEvent{
+				mockHistoryEvent(shared.EventTypeTimerCanceled),
+			},
+			expectError: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			info := &WorkflowInfo{} // Assuming WorkflowInfo is a struct you have defined
+			err := matchReplayWithHistory(info, tc.replayDecisions, tc.historyEvents)
+			if tc.expectError {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}
+
+func mockHistoryEvent(eventType shared.EventType) *shared.HistoryEvent {
+	event := &shared.HistoryEvent{
+		EventType: &eventType,
+	}
+
+	switch eventType {
+	case shared.EventTypeActivityTaskScheduled:
+		event.ActivityTaskScheduledEventAttributes = &shared.ActivityTaskScheduledEventAttributes{
+			ActivityId:   common.StringPtr("mockActivityId"),
+			ActivityType: &shared.ActivityType{Name: common.StringPtr("mockActivityType")},
+			TaskList:     &shared.TaskList{Name: common.StringPtr("mockTaskList")},
+			Input:        []byte("mockInput"),
+		}
+	case shared.EventTypeTimerCanceled: // Newly added case
+		event.TimerCanceledEventAttributes = &shared.TimerCanceledEventAttributes{
+			TimerId: common.StringPtr("mockTimerId"),
+		}
+	}
+
+	return event
+}
+
+func mockDecision(decisionType shared.DecisionType) *shared.Decision {
+	decision := &shared.Decision{
+		DecisionType: &decisionType,
+	}
+
+	switch decisionType {
+	case shared.DecisionTypeScheduleActivityTask:
+		decision.ScheduleActivityTaskDecisionAttributes = &shared.ScheduleActivityTaskDecisionAttributes{
+			ActivityId:   common.StringPtr("mockActivityId"),
+			ActivityType: &shared.ActivityType{Name: common.StringPtr("mockActivityType")},
+			TaskList:     &shared.TaskList{Name: common.StringPtr("mockTaskList")},
+			Input:        []byte("mockInput"),
+		}
+	case shared.DecisionTypeStartTimer: // Newly added case
+		decision.StartTimerDecisionAttributes = &shared.StartTimerDecisionAttributes{
+			TimerId:                   common.StringPtr("mockTimerId"),
+			StartToFireTimeoutSeconds: common.Int64Ptr(60), // Example value
+		}
+	}
+
+	return decision
+}