Package httptest


Package httptest provides utilities for HTTP testing.


Package files

httptest.go recorder.go server.go


DefaultRemoteAddr is the default remote address to return in RemoteAddr if an explicit DefaultRemoteAddr isn't set on ResponseRecorder.

const DefaultRemoteAddr = ""

func NewRequestSource

func NewRequest(method, target string, body io.Reader) *http.Request

NewRequest returns a new incoming server Request, suitable for passing to an http.Handler for testing.

The target is the RFC 7230 "request-target": it may be either a path or an absolute URL. If target is an absolute URL, the host name from the URL is used. Otherwise, "example.com" is used.

The TLS field is set to a non-nil dummy value if target has scheme "https".

The Request.Proto is always HTTP/1.1.

An empty method means "GET".

The provided body may be nil. If the body is of type *bytes.Reader, *strings.Reader, or *bytes.Buffer, the Request.ContentLength is set.

NewRequest panics on error for ease of use in testing, where a panic is acceptable.

To generate a client HTTP request instead of a server request, see the NewRequest function in the net/http package.

type ResponseRecorderSource

ResponseRecorder is an implementation of http.ResponseWriter that records its mutations for later inspection in tests.

type ResponseRecorder struct {
        // Code is the HTTP response code set by WriteHeader.
        // Note that if a Handler never calls WriteHeader or Write,
        // this might end up being 0, rather than the implicit
        // http.StatusOK. To get the implicit value, use the Result
        // method.
        Code int

        // HeaderMap contains the headers explicitly set by the Handler.
        // To get the implicit headers set by the server (such as
        // automatic Content-Type), use the Result method.
        HeaderMap http.Header

        // Body is the buffer to which the Handler's Write calls are sent.
        // If nil, the Writes are silently discarded.
        Body *bytes.Buffer

        // Flushed is whether the Handler called Flush.
        Flushed bool
        // contains filtered or unexported fields


package main

import (

func main() {
	handler := func(w http.ResponseWriter, r *http.Request) {
		io.WriteString(w, "<html><body>Hello World!</body></html>")

	req := httptest.NewRequest("GET", "http://example.com/foo", nil)
	w := httptest.NewRecorder()
	handler(w, req)

	resp := w.Result()
	body, _ := ioutil.ReadAll(resp.Body)



func NewRecorderSource

func NewRecorder() *ResponseRecorder

NewRecorder returns an initialized ResponseRecorder.

func (*ResponseRecorder) FlushSource

func (rw *ResponseRecorder) Flush()

Flush sets rw.Flushed to true.

func (*ResponseRecorder) HeaderSource

func (rw *ResponseRecorder) Header() http.Header

Header returns the response headers.

func (*ResponseRecorder) ResultSource

func (rw *ResponseRecorder) Result() *http.Response

Result returns the response generated by the handler.

The returned Response will have at least its StatusCode, Header, Body, and optionally Trailer populated. More fields may be populated in the future, so callers should not DeepEqual the result in tests.

The Response.Header is a snapshot of the headers at the time of the first write call, or at the time of this call, if the handler never did a write.

The Response.Body is guaranteed to be non-nil and Body.Read call is guaranteed to not return any error other than io.EOF.

Result must only be called after the handler has finished running.

func (*ResponseRecorder) WriteSource

func (rw *ResponseRecorder) Write(buf []byte) (int, error)

Write always succeeds and writes to rw.Body, if not nil.

func (*ResponseRecorder) WriteHeaderSource

func (rw *ResponseRecorder) WriteHeader(code int)

WriteHeader sets rw.Code. After it is called, changing rw.Header will not affect rw.HeaderMap.

func (*ResponseRecorder) WriteStringSource

func (rw *ResponseRecorder) WriteString(str string) (int, error)

WriteString always succeeds and writes to rw.Body, if not nil.

type ServerSource

A Server is an HTTP server listening on a system-chosen port on the local loopback interface, for use in end-to-end HTTP tests.

type Server struct {
        URL      string // base URL of form http://ipaddr:port with no trailing slash
        Listener net.Listener

        // TLS is the optional TLS configuration, populated with a new config
        // after TLS is started. If set on an unstarted server before StartTLS
        // is called, existing fields are copied into the new config.
        TLS *tls.Config

        // Config may be changed after calling NewUnstartedServer and
        // before Start or StartTLS.
        Config *http.Server
        // contains filtered or unexported fields


package main

import (

func main() {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintln(w, "Hello, client")
	defer ts.Close()

	res, err := http.Get(ts.URL)
	if err != nil {
	greeting, err := ioutil.ReadAll(res.Body)
	if err != nil {

	fmt.Printf("%s", greeting)

func NewServerSource

func NewServer(handler http.Handler) *Server

NewServer starts and returns a new Server. The caller should call Close when finished, to shut it down.

func NewTLSServerSource

func NewTLSServer(handler http.Handler) *Server

NewTLSServer starts and returns a new Server using TLS. The caller should call Close when finished, to shut it down.

func NewUnstartedServerSource

func NewUnstartedServer(handler http.Handler) *Server

NewUnstartedServer returns a new Server but doesn't start it.

After changing its configuration, the caller should call Start or StartTLS.

The caller should call Close when finished, to shut it down.

func (*Server) CloseSource

func (s *Server) Close()

Close shuts down the server and blocks until all outstanding requests on this server have completed.

func (*Server) CloseClientConnectionsSource

func (s *Server) CloseClientConnections()

CloseClientConnections closes any open HTTP connections to the test Server.

func (*Server) StartSource

func (s *Server) Start()

Start starts a server from NewUnstartedServer.

func (*Server) StartTLSSource

func (s *Server) StartTLS()

StartTLS starts TLS on a server from NewUnstartedServer.

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Licensed under the Creative Commons Attribution License 3.0.