如何使用Go语言模拟一个带有方法的虚拟gRPC服务

huangapple
go评论128阅读模式
英文:

How to mock a dummy grpc service with methods in Go

问题

我需要为一个函数编写单元测试，该函数在其源代码中调用了一个不同的 gRPC 服务的 gRPC 方法。我的测试结果出现了 panic 错误，因为该 gRPC 服务没有在我的机器上运行。我想在我的测试中创建一个虚拟服务，并且该服务必须提供源代码中调用的方法。我该如何做？

编辑：细节
源函数：

  1. func (s *mainType) MainGenerateBearerToken(inputs...)(output) {
  2.     response, err := s.Subtype.SubGenerateBearerToken(context, authnPass, ttl)
  3.     if err != nil {
  4.         return nil, err
  5.     }
  6.     return &models.OCITokenResponse{Token: response.Token, ExpiresIn: ttl}, nil
  7. }
  9. func(cl *Subtype) SubGenerateBearerToken(context,authnPass, ttl) (*BearerTokenResponse, error) {
  10.     resp,err := pb.NewGrpcClient(cl.Conn).GetBearerToken_grpc(ctx, &pb.GetBearerTokenRequest{AuthnToken, BearerTtlValue:ttlNum)
  11.     return &BearerTokenResponse{Token}, err
  12. }

我正在为 MainGenerateBearerToken() 函数编写测试，该函数调用 SubGenerateBearerToken()，而 SubGenerateBearerToken() 中调用了 gRPC 方法。

英文:

I need to write unit test for a function, which in its source code calling a gRPC method of a different gRPC service. My test result in panic error because that gRPC service is not running on my machine. I want to create a dummy service in my test and that service must serve the method calling inside the source code. How do I do that?

Edit: Details
Source function:

  1. func (s *mainType) MainGenerateBearerToken(inputs...)(output) {
  2.     	response, err := s.Subtype.SubGenerateBearerToken(context, authnPass, ttl)
  3.     	if err != nil {
  4.     		return nil, err
  5.     	}
  6.     	return &models.OCITokenResponse{Token: response.Token, ExpiresIn: ttl}, nil
  7.     }
  9. func(cl *Subtype) SubGenerateBearerToken(context,authnPass, ttl) (*BearerTokenResponse, error) {
  10. 	
  11. 	resp,err := pb.NewGrpcClient(cl.Conn).GetBearerToken_grpc(ctx, &pb.GetBearerTokenRequest{AuthnToken, BearerTtlValue:ttlNum)
  12. 	
  13. 	return &BearerTokenResponse{Token}, err
  14. }

I'm writing test for the MainGenerateBearerToken() function, which calls SubGenerateBearerToken(), inside which the grpc method is called.

答案1

得分: 1

一个 gRPC 服务客户端是一个普通的 Go 接口。

你可以使用像 gomock 或 moq 这样的工具为任何 Go 接口生成模拟。

  1. $ go install github.com/golang/mock/mockgen@v1.6.0
  2. $ mockgen -source=my_service.pb.go MyServiceClient

或者

  1. $ go install github.com/matryer/moq@v0.2.5
  2. $ moq -pkg mock -out mock/my_service.go . MyServiceClient

这将生成一个实现 MyServiceClient 接口的 mock.MyServiceClientMock。然后你可以在单元测试中使用它，而不是真正的 gRPC 客户端。

使用 moq 的完整示例：

my_service.proto:

  1. syntax = "proto3";
  3. package main;
  4. option go_package = "main";
  6. service MyService {
  7.     rpc Hello(HelloMesage) returns (HelloMesage) {}
  8. }
  10. message HelloMesage {
  11.   string msg = 1;
  12. }

main.go:

  1. package main
  3. import context "context"
  5. //go:generate protoc --go_out=plugins=grpc:. -I=. my_service.proto
  6. //go:generate moq -out my_service_mock.go . MyServiceClient
  8. func CallHello(myService MyServiceClient) (*HelloMesage, error) {
  9. 	return myService.Hello(context.TODO(), &HelloMesage{Msg: "hello"})
  10. }
  12. func main() {
  13. 	// (omitted) 正常调用 grpc ...
  14. }

main_test.go:

  1. package main
  3. import (
  4. 	context "context"
  5. 	"testing"
  7. 	"github.com/stretchr/testify/assert"
  8. 	grpc "google.golang.org/grpc"
  9. )
  11. func TestCallHello(t *testing.T) {
  12. 	myServiceClient := &MyServiceClientMock{
  13. 		HelloFunc: func(ctx context.Context, in *HelloMesage, opts ...grpc.CallOption) (*HelloMesage, error) {
  14. 			return &HelloMesage{Msg: in.Msg + " reply"}, nil
  15. 		},
  16. 	}
  17. 	res, err := CallHello(myServiceClient)
  18. 	assert.NoError(t, err)
  19. 	assert.Equal(t, "hello reply", res.Msg)
  21. }

运行：

  1. $ go mod init myservice
  2. $ go mod tidy
  3. $ go generate
  4. $ go test
英文:

A gRPC service client is a regular Go interface.

You can use tools like gomock or moq to generate a mock for any Go interface.

  1. $ go install github.com/golang/mock/mockgen@v1.6.0
  2. $ mockgen -source=my_service.pb.go MyServiceClient

Or

  1. $ go install github.com/matryer/moq@v0.2.5
  2. $ moq -pkg mock -out mock/my_service.go . MyServiceClient

That will generate mock.MyServiceClientMock that implements MyServiceClient. Then you can use it in your unit tests instead of the real gRPC client.

Complete example using moq:

my_service.proto:

  1. syntax = "proto3";
  3. package main;
  4. option go_package = "main";
  6. service MyService {
  7.     rpc Hello(HelloMesage) returns (HelloMesage) {}
  8. }
  10. message HelloMesage {
  11.   string msg = 1;
  12. }

main.go:

  1. package main
  3. import context "context"
  5. //go:generate protoc --go_out=plugins=grpc:. -I=. my_service.proto
  6. //go:generate moq -out my_service_mock.go . MyServiceClient
  8. func CallHello(myService MyServiceClient) (*HelloMesage, error) {
  9. 	return myService.Hello(context.TODO(), &HelloMesage{Msg: "hello"})
  10. }
  12. func main() {
  13. 	// (omitted) call grpc normally ...
  14. }

main_test.go:

  1. package main
  3. import (
  4. 	context "context"
  5. 	"testing"
  7. 	"github.com/stretchr/testify/assert"
  8. 	grpc "google.golang.org/grpc"
  9. )
  11. func TestCallHello(t *testing.T) {
  12. 	myServiceClient := &MyServiceClientMock{
  13. 		HelloFunc: func(ctx context.Context, in *HelloMesage, opts ...grpc.CallOption) (*HelloMesage, error) {
  14. 			return &HelloMesage{Msg: in.Msg + " reply"}, nil
  15. 		},
  16. 	}
  17. 	res, err := CallHello(myServiceClient)
  18. 	assert.NoError(t, err)
  19. 	assert.Equal(t, "hello reply", res.Msg)
  21. }

To run:

  1. $ go mod init myservice
  2. $ go mod tidy
  3. $ go generate
  4. $ go test

答案2

得分: 0

如果在SubGenerateBearerToken方法中删除grpc客户端的创建是合适的（例如，将其保留在子类型中或作为参数传递），你可以轻松地创建一个简单的假客户端：

  1. type fakeClient struct {
  2.     grpc.YourClient // 来自*.pb.go文件的客户端接口
  3. }
  5. func NewFakeClient(_ *grpc.ClientConn) *fakeClient {
  6.     return &fakeClient{}
  7. }
  9. func (fc *fakeClient) GetBearerToken_grpc(ctx context.Context, in *pb.GetBearerTokenRequest, opts ...grpc.CallOption) (*pb.BearerTokenResponse, error) {
  10.     return &pb.BearerTokenResponse{
  11.         // 你的假响应...
  12.     }, nil
  13. }
英文:

If it's appropriate to get rid of the grpc client creation in the SubGenerateBearerToken method (e.g. keep it in the Subtype or pass as an arg) you could easily create a simple fake client:

  1. type fakeClient struct {
  2. 	grpc.YourClient // a client interface from your *.pb.go file
  3. }
  5. func NewFakeClient(_ *grpc.ClientConn) *fakeClient {
  6. 	return &fakeClient{}
  7. }
  9. func (fc *fakeClient) GetBearerToken_grpc(ctx context.Context, in *pb.GetBearerTokenRequest, opts ...grpc.CallOption) (*pb.BearerTokenResponse, error) {
  10. 	return &pb.BearerTokenResponse{
  11.         // your fake response...
  12.     }, nil
  13. }

huangapple
  • 本文由 发表于 2022年2月28日 20:47:15
  • 转载请务必保留本文链接：https://go.coder-hub.com/71295259.html
  • go
  • grpc
  • grpc-go
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