encoding/json: test style tweaks

Rename test name from Http to HTTP, and fix some style nits.

Change-Id: I00fe1cecd69ca2f50be86a76ec90031c2f921707
Reviewed-on: https://go-review.googlesource.com/12760Reviewed-by: Andrew Gerrand <adg@golang.org>

src/encoding/json/stream_test.go

@@ -319,43 +319,36 @@ func TestDecodeInStream(t *testing.T) {
 
 }
 
-const raw = `{ "foo": "bar" }`
+// Test from golang.org/issue/11893
+func TestHTTPDecoding(t *testing.T) {
+	const raw = `{ "foo": "bar" }`
 
-func makeHTTP() io.ReadCloser {
-	mux := http.NewServeMux()
-	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte(raw))
-	})
-	ts := httptest.NewServer(mux)
+	}))
 	defer ts.Close()
 	res, err := http.Get(ts.URL)
 	if err != nil {
 		log.Fatalf("GET failed: %v", err)
 	}
-	return res.Body
-}
-
-func TestHttpDecoding(t *testing.T) {
+	defer res.Body.Close()
 
 	foo := struct {
 		Foo string
 	}{}
 
-	rc := makeHTTP()
-	defer rc.Close()
-
-	d := NewDecoder(rc)
-	err := d.Decode(&foo)
+	d := NewDecoder(res.Body)
+	err = d.Decode(&foo)
 	if err != nil {
-		t.Errorf("Unexpected error %v", err)
+		t.Fatalf("Decode: %v", err)
 	}
 	if foo.Foo != "bar" {
-		t.Errorf("Expected \"bar\", was %v", foo.Foo)
+		t.Errorf("decoded %q; want \"bar\"", foo.Foo)
 	}
 
 	// make sure we get the EOF the second time
 	err = d.Decode(&foo)
 	if err != io.EOF {
-		t.Errorf("Expected io.EOF, was %v", err)
+		t.Errorf("err = %v; want io.EOF", err)
 	}
 }