mtf

Microservice Test Framework

Introduction

This Microservice Test Framework (MTF) allows in simple way to mock service dependencies and setup docker test environment in a comprehensive way.

Supported dependencies:

• GRPC client/server communication
• Google Cloud Pubsub
• Google Cloud Storage (Partial - only bucket object Insert/Get operation)
• FTP
• HTTP/HTTPS integration
• MySQL
• Redis

The aim of the MTF framework is not only cut dependencies require to run your binary and execute tests but also focus on test readability.

Getting started

To begin using MTF framework you will need to define TestMain function and setup required environment used for binary that you would like to test further called SUT (System Under Test). To setup prerequisite dependency for your SUT the framework.TestEnv function should be invoked. With...() functions method chain allows to set up and configure dependency for SUT. Finally the .Run() chain method function starts the test.

func TestMain(m *testing.M) {
	framework.TestEnv(m).
		WithSUT(framework.SutSettings{
			Dir:   "./service", // dir with source files of system under test.
			Ports: []int{8001},
			Envs: []string{
				"ORACLE_ADDR=" + framework.GetDockerHostAddr(8002),
			}}).
		WithRedis(framework.RedisSettings{
			Password: "test",
		}).
		WithMySQL(framework.MysqlSettings{
			DatabaseName: "test_db",
			MigrationDir: "./service/migrations",
			Password:     "test",
		}).Run()
}

SuiteTest collects and groups collection of ports that allows to communicate with external mocked dependency.

type SuiteTest struct {
	echoPort   *port.Port
	httpPort   *port.Port
	oraclePort *port.Port
}

Ports initialization should be done within Suite Init(t *testing.T) function.

func (st *SuiteTest) Init(t *testing.T) {
	var err error
	if st.echoPort, err = port.NewGRPCClientPort((*pb.EchoClient)(nil), "localhost:8001"); err != nil {
		t.Fatalf("failed to init grpc client port")
	}
	st.httpPort = port.NewHTTPPort()
	if st.oraclePort, err = port.NewGRPCServerPort((*pbo.OracleServer)(nil), ":8002"); err != nil {
		t.Fatalf("failed to init grpc oracle server")
	}
}

Ports

Port are used to communicate with dependencies by sending and receiving messages in a consistent way.

GRPC Client/Server port port.NewGRPCServerPort port.NewGRPCClientPort

GRPC ports allows to mock whole grpc communication between client<->SUT<->Other GRPC service.

Server grpc port initialization:

oraclePort, err = port.NewGRPCServerPort((*pbo.OracleServer)(nil), ":8002")

Client port initialization:

echoPort, err = port.NewGRPCClientPort((*pb.EchoClient)(nil), "localhost:8001")

Example of sut gprc method handler:

func (s *server) AskOracle(ctx context.Context, req *pb.AskOracleRequest) (*pb.AskOracleResponse, error) {
	resp, err := s.OracleClient.AskDeepThought(ctx, &pbo.AskDeepThoughtRequest{
		Data: req.GetData(),
	})
	if err != nil {
		switch status.Code(err) {
		case codes.FailedPrecondition:
			return &pb.AskOracleResponse{
				Data: "Come back after seven and a half million years",
			}, nil
		default:
			return nil, err
		}
	}
	return &pb.AskOracleResponse{
		Data: resp.GetData(),
	}, nil
}

Test GRPC message flow:

func (st *SuiteTest) TestClientServerGRPC(t *testing.T) {
	st.echoPort.Send(t, &pb.AskOracleRequest{
		Data: "Get answer for ultimate question of life the universe and everything",
	})
	st.oraclePort.Receive(t, &pbo.AskDeepThoughtRequest{
		Data: "Get answer for ultimate question of life the universe and everything",
	})
	st.oraclePort.Send(t, &pbo.AskDeepThoughtResponse{
		Data: "42",
	})
	st.echoPort.Receive(t, &pb.AskOracleResponse{
		Data: "42",
	})
}

--- PASS: TestEchoService (0.75s)
    --- PASS: TestEchoService/TestClientServerGRPC (0.01s)
PASS

If we change the handler body by adding additional text to AskOracleResponse.Date:

@@ -110,6 +110,6 @@ func (s *server) AskOracle(ctx context.Context, req *pb.AskOracleRequest) (*pb.A
                return nil, err
        }
        return &pb.AskOracleResponse{
-               Data: resp.GetData(),
+               Data: resp.GetData() + "!!!",
        }, nil
 }

The echoPort.Receive(t, &pb.AskOracleResponse{...} call will log port mismatch

--- FAIL: TestEchoService/TestClientServerGRPC (0.01s)
port.go:89: Failed to receive *echo.AskOracleResponse:
     deep equal:
     got:'{
     "data": "42!!!!"
    }'
     exp: '{
     "data": "42"
    }'
    : match not eq

Mock GRPC error response:

func (st *SuiteTest) TestClientServerGRPCError(t *testing.T) {
	st.echoPort.Send(t, &pb.AskOracleRequest{
		Data: "Get answer for ultimate question of life the universe and everything",
	})
	st.oraclePort.Receive(t, &pbo.AskDeepThoughtRequest{
		Data: "Get answer for ultimate question of life the universe and everything",
	})
	st.oraclePort.Send(t, &port.GRPCErr{
		Err: status.Errorf(codes.FailedPrecondition, "Deepthought error"),
	})
	st.echoPort.Receive(t, &pb.AskOracleResponse{
		Data: "Come back after seven and a half million years",
	})
}

HTTP/HTTPS Port port.NewHTTPPort()

HTTP port allows to test external http endpoint integration by matching SUT's http requests and sending back custom shape responses.

func (st *SuiteTest) TestHTTP(t *testing.T) {
	st.httpPort.Receive(t, &port.HTTPRequest{
		Body:   []byte{},
		Method: "GET",
		Host:   "example.com",
		URL:    "/urlpath",
	})

	st.httpPort.Send(t, &port.HTTPResponse{
		Body:   []byte(`{"value":{"joke":"42"}}`),
		Status: http.StatusOK,
	})
}

GRPC and HTTPS with TLS support

The framework.WithTLS(framework.TLSSettings{Hosts: []string{"customdomain.com"}) chain method of framework.TestEnv allows to set custom DNSNames that will be added to TLS. In order to create grpc TLS server or client the port port.WithTLS options should be pass to NewGRPCServerPort or NewGRPCClientPort port funciton. Under the hood the mtf framework will create cert key pair in /tmp/mtf/ that will be propagated to dependencies during test execution.

Match mtf/match

Match only respnse message type:

echoPort.Receive(t, match.Type(&pb.AskOracleResponse{})

Match response by custom function:

echoPort.Receive(t, match.Fn(func(resp *pb.AskGoogleResponse) {
		if got, want := len(resp.GetData()), 2; got != want {
			t.Fatalf("data len mismatch, got: %v want: %v", got, want)
		}
	}))

Match response GRPC Error status code:

echoPort.Receive(t, match.GRPCStatusCode(codes.Internal))

MTF Tests execution

Right now MTF framework does not support parallel test execution and to prevent simultaneously test run passing the -p 1 flag to go test command is required.

Run tests examples:

go test ./example/... -p 1 --rebuild_binary=true  -tags=mtf

Test Environment preparation phase

At first run the mtf will download docker images dependency needed to prepare and run test environment:

=== PREPARING TEST ENV
  - Starting [REDIS Component] -  1.601356005s
  - Starting [MYSQL Component] -  50.75908ms
  - Starting [MIGRATE Component] -  805.090778ms
  - Starting [SUT Component] -  5.895084273s
=== TEST RUN DONE - 11.863770827s