net/http/httptest: NewRequest sets body to {} instead of nil

[devdinu]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version go1.8rc2 darwin/amd64

What operating system and processor architecture are you using (go env)?

GOBIN="/Users/dineshkumar/Documents/Learn/Golang/workspace/bin"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/dineshkumar/Documents/Learn/Golang/workspace"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/cw/0ps5z6nd6m19x9vpdrwlbm_m0000gn/T/go-build939833936=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
PKG_CONFIG="pkg-config"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"

What did you do?

httptest.NewRequest("GET", "/path/some_url", nil)

import (
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestHttpNewRequest(t *testing.T) {
	r := httptest.NewRequest(http.MethodGet, "/some_url", nil)
	httpRequest, _ := http.NewRequest(http.MethodGet, "/some_url", nil)

	dummyHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Body != nil {
			t.Log("body should be nil")
			t.FailNow()
		}
	})

	dummyHandler(httptest.NewRecorder(), httpRequest)
	t.Log("http Request works as expected")
	dummyHandler(httptest.NewRecorder(), r)
	t.Log("httptest Request works as expected")
}

What did you expect to see?

httptest request works as expected, which is its body to be nil.

What did you see instead?

it fails for body being not nil. it actually sets the body to be {}.

[bradfitz]

Working as intended:

https://golang.org/pkg/net/http/#Request.Body

        // For server requests the Request Body is always non-nil
        // but will return EOF immediately when no body is present.
        // The Server will close the request body. The ServeHTTP
        // Handler does not need to.

[devdinu]

@bradfitz sorry, could you please elaborate for me to understand, so if it should be non-nil then why does http.NewRequest results in nil body?

(or) Does this mean when the request is sent to (actual) server it will have an empty body?

[bradfitz]

httptest.NewRequest is for generating incoming (server) requests, for an http.Handler.

http.NewRequest is for generating outgoing (client) requests, for http.Transport.

The Request fields have slightly different (but documented) semantics and requirements for client vs. server.