Add unit tests for frontend handler covering shutting down branch (ca…

…dence-workflow#6466)

service/frontend/api/refresh_workflow_tasks.go

@@ -26,13 +26,17 @@ import (
 	"context"
 
 	"github.com/uber/cadence/common/types"
+	"github.com/uber/cadence/service/frontend/validate"
 )
 
 // RefreshWorkflowTasks re-generates the workflow tasks
 func (wh *WorkflowHandler) RefreshWorkflowTasks(
 	ctx context.Context,
 	request *types.RefreshWorkflowTasksRequest,
 ) error {
+	if wh.isShuttingDown() {
+		return validate.ErrShuttingDown
+	}
 	if err := wh.requestValidator.ValidateRefreshWorkflowTasksRequest(ctx, request); err != nil {
 		return err
 	}

service/frontend/api/shutting_down_test.go

@@ -0,0 +1,82 @@
+// 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 api
+
+import (
+	"context"
+	"reflect"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestShuttingDownError(t *testing.T) {
+	wh, _ := setupMocksForWorkflowHandler(t)
+	wh.Stop()
+
+	// get all methods of Handler interface
+	tt := reflect.TypeOf(struct{ Handler }{})
+	methodNames := make(map[string]struct{})
+	for i := 0; i < tt.NumMethod(); i++ {
+		methodNames[tt.Method(i).Name] = struct{}{}
+	}
+	delete(methodNames, "GetClusterInfo")
+	delete(methodNames, "Health")
+
+	v := reflect.ValueOf(wh)
+	for name := range methodNames {
+		method := v.MethodByName(name)
+		methodType := method.Type()
+		if methodType.Kind() != reflect.Func {
+			t.Fatalf("method: %s is not a function - %s", name, methodType.String())
+		}
+		if methodType.IsVariadic() {
+			t.Fatalf("method: %s is variadic - %s", name, methodType.String())
+		}
+		if methodType.NumIn() < 1 || methodType.NumIn() > 2 {
+			t.Fatalf("method: %s has wrong number of inputs - %s", name, methodType.String())
+		}
+
+		var results []reflect.Value
+		if methodType.NumIn() == 1 {
+			results = method.Call([]reflect.Value{reflect.ValueOf(context.Background())})
+		} else {
+			results = method.Call([]reflect.Value{reflect.ValueOf(context.Background()), reflect.Zero(methodType.In(1))})
+		}
+		if len(results) == 1 {
+			err, ok := results[0].Interface().(error)
+			if !ok {
+				t.Fatalf("method: %s has wrong output type - %s", name, methodType.String())
+			}
+			assert.ErrorContains(t, err, "Shutting down")
+		} else if len(results) == 2 {
+			err, ok := results[1].Interface().(error)
+			if !ok {
+				t.Fatalf("method: %s has wrong output type - %s", name, methodType.String())
+			}
+			assert.ErrorContains(t, err, "Shutting down")
+		} else {
+			t.Fatalf("method: %s has wrong number of outputs - %s", name, methodType.String())
+		}
+	}
+}