Unit test for the fetcher/current.go. (#5504)

* resolved merge conflicts

* deleted extra file

* Some file

* Added a unit test for the fetcher/current.go

* Removed the finish call

common/reconciliation/fetcher/current_test.go

@@ -0,0 +1,103 @@
+// The MIT License (MIT)
+//
+// Copyright (c) 2017-2020 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 fetcher
+
+import (
+	"context"
+	"testing"
+
+	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/require"
+	"github.com/uber/cadence/common/pagination"
+	"github.com/uber/cadence/common/persistence"
+	"github.com/uber/cadence/common/reconciliation/entity"
+)
+
+func TestGetCurrentExecution(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	mockRetryer := persistence.NewMockRetryer(ctrl)
+	ctx := context.Background()
+	pageSize := 10
+
+	testCases := []struct {
+		name          string
+		setupMock     func()
+		expectedPage  pagination.Page
+		expectedError bool
+	}{
+		{
+			name: "Success",
+			setupMock: func() {
+				executions := []*persistence.CurrentWorkflowExecution{
+					{
+						DomainID:     "testDomainID",
+						WorkflowID:   "testWorkflowID",
+						RunID:        "testRunID",
+						State:        persistence.WorkflowStateRunning,
+						CurrentRunID: "testCurrentRunID", // Setting CurrentRunID
+					},
+				}
+
+				mockRetryer.EXPECT().
+					ListCurrentExecutions(ctx, &persistence.ListCurrentExecutionsRequest{
+						PageSize: pageSize,
+					}).
+					Return(&persistence.ListCurrentExecutionsResponse{
+						Executions: executions,
+						PageToken:  nil,
+					}, nil)
+
+				mockRetryer.EXPECT().GetShardID().Return(123)
+			},
+			expectedPage: pagination.Page{
+				Entities: []pagination.Entity{
+					&entity.CurrentExecution{
+						CurrentRunID: "testCurrentRunID", // This should match with the mocked data
+						Execution: entity.Execution{
+							ShardID:    123,
+							DomainID:   "testDomainID",
+							WorkflowID: "testWorkflowID",
+							RunID:      "testRunID",
+							State:      persistence.WorkflowStateRunning,
+						},
+					},
+				},
+			},
+			expectedError: false,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			tc.setupMock()
+			fetchFn := getCurrentExecution(mockRetryer, pageSize)
+			page, err := fetchFn(ctx, nil)
+
+			if tc.expectedError {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				require.Equal(t, tc.expectedPage, page)
+			}
+		})
+	}
+}