httputil: add test for CloseBody

Change-Id: I6049de69279aef7bb0c013935ae4d37b8eaff853

pkg/httputil/httputil.go

@@ -318,9 +318,6 @@ func CloseBody(rc io.ReadCloser) {
 	// Content-Length.  Or maybe Go 1.3's Close itself would look
 	// to see if we're at EOF even if it hasn't been Read.
 
-	// TODO: reflect to get the type name, and avoid this Read
-	// if it's seen EOF? Maybe more expensive.
-
 	// TODO: use a bytepool package somewhere for these two bytes.
 	rc.Read(make([]byte, 2))
 	rc.Close()

pkg/httputil/httputil_test.go

@@ -0,0 +1,61 @@
+/*
+Copyright 2014 The Camlistore Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package httputil
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"testing"
+)
+
+func TestCloseBody(t *testing.T) {
+	const msg = "{\"foo\":\"bar\"}\r\n"
+	addrSeen := make(map[string]int)
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		addrSeen[r.RemoteAddr]++
+		w.Header().Set("Content-Length", strconv.Itoa(len(msg)))
+		w.WriteHeader(200)
+		w.Write([]byte(msg))
+	}))
+	defer ts.Close()
+
+	buf := make([]byte, len(msg))
+
+	for _, trim := range []int{0, 2} {
+		for i := 0; i < 3; i++ {
+			res, err := http.Get(ts.URL)
+			if err != nil {
+				t.Errorf("Get: %v", err)
+				continue
+			}
+			want := len(buf) - trim
+			n, err := res.Body.Read(buf[:want])
+			CloseBody(res.Body)
+			if n != want {
+				t.Errorf("Read = %v; want %v", n, want)
+			}
+			if err != nil && err != io.EOF {
+				t.Errorf("Read = %v", err)
+			}
+		}
+	}
+	if len(addrSeen) != 1 {
+		t.Errorf("server saw %d distinct client addresses; want 1", len(addrSeen))
+	}
+}