Quick start

HTTP

A test starts a server, adds a mock, and points the code under test at m.URL(...):

func Example() {
	m := mockhttp.MustNew(mockhttp.Setup().Silent())
	m.MustStart()
	defer m.Close()

	scoped := m.MustMock(mockhttp.Getf("/hello").Reply(mockhttp.OK().PlainText("hello world")))

	res, err := http.Get(m.URL("/hello"))
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()

	body, err := io.ReadAll(res.Body)
	if err != nil {
		panic(err)
	}

	fmt.Println(res.StatusCode, string(body), scoped.Called())
	// Output: 200 hello world true
}

In a test, use t.Cleanup(m.Close) in place of defer, and scoped.AssertCalled(t) to fail the test when the mock wasn't called:

func TestHello(t *testing.T) {
	m := mockhttp.MustNew()
	m.MustStart()
	t.Cleanup(m.Close)

	scoped := m.MustMock(mockhttp.Getf("/hello").Reply(mockhttp.OK().PlainText("hello world")))

	// ... call m.URL("/hello") ...

	scoped.AssertCalled(t)
}

mockhttp.New does the same as MustNew but returns an error instead of panicking. Pass mockhttp.Setup() to either one to configure the server: its address, TLS, CORS, proxying or recording, for example.

gRPC

A gRPC mock server serves any method of the services whose generated code the program imports. InMemory() needs no port: m.Dial() connects to it.

func Example() {
	m := mockgrpc.MustNew(mockgrpc.Setup().Silent().InMemory())
	m.MustStart()
	defer m.Close()

	m.MustMock(mockgrpc.Method("TestService/Greetings").
		Field("message", match.Equal("hi")).
		Reply(mockgrpc.Message(&pb.HiRes{Message: "hello"})))

	res, err := pb.NewTestServiceClient(m.MustDial()).Greetings(context.Background(), &pb.HiReq{Message: "hi"})
	if err != nil {
		panic(err)
	}

	fmt.Println(res.GetMessage())
	// Output: hello
}

The CLI

Write a mock file:

# testdata/vlatte/_mocks/hello_mock.yaml
request:
  method: GET
  path: /hello
response:
  status: 200
  body: hello world

Serve it:

vlatte --addr=127.0.0.1:8080
curl http://127.0.0.1:8080/hello

Next

• Concepts: mocks, matchers, replies and servers.
• HTTP and gRPC: everything each protocol does.
• Guides: longer walkthroughs.