net/http/httptest: add examples

R=golang-dev, adg, bradfitz
CC=golang-dev
https://golang.org/cl/7314046

src/pkg/net/http/httptest/example_test.go

+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package httptest_test
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/http/httptest"
+)
+
+func ExampleRecorder() {
+	handler := func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, "something failed", http.StatusInternalServerError)
+	}
+
+	req, err := http.NewRequest("GET", "http://example.com/foo", nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	w := httptest.NewRecorder()
+	handler(w, req)
+
+	fmt.Printf("%d - %s", w.Code, w.Body.String())
+	// Output: 500 - something failed
+}
+
+func ExampleServer() {
+	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 {
+		log.Fatal(err)
+	}
+	greeting, err := ioutil.ReadAll(res.Body)
+	res.Body.Close()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("%s", greeting)
+	// Output: Hello, client
+}