memhttp provides a full net/http server and client that communicate over in-memory pipes rather than the network. This is often useful in tests, where you want to avoid localhost networking but don't want to stub out all the complexity of HTTP.

Occasionally, it's also useful in production code: if you're planning to split a monolithic application into microservices, you can first use memhttp to simulate the split. This allows you to rewrite local function calls as HTTP calls (complete with serialization, compression, and middleware) while retaining the ability to quickly change service boundaries.

In particular, memhttp pairs well with connect-go RPC servers.

go get go.akshayshah.org/memhttp

In-memory HTTP is most common in tests, so most users will be best served by the memhttptest subpackage:

func TestServer(t *testing.T) {
  hello := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    io.WriteString(w, "Hello, world!")
  })
  // The server starts automatically, and it shuts down gracefully when the
  // test ends. Startup and shutdown errors fail the test.
  //
  // By default, servers and clients use TLS and support HTTP/2.
  srv := memhttptest.New(t, hello)
  res, err := srv.Client().Get(srv.URL())
  if err != nil {
    t.Fatal(err)
  }
  if res.StatusCode != http.StatusOK {
    t.Error(res.Status)
  }
}

This module is unstable, with a stable release expected before the end of 2023. It supports the two most recent major releases of Go.

Within those parameters, memhttp follows semantic versioning.

Offered under the MIT license.