test: use Fprintf to simplify writing headers (#1510)

Author: alexandear

server_test.go

@@ -3772,7 +3772,7 @@ func TestStreamRequestBody(t *testing.T) {
 	pipe := fasthttputil.NewPipeConns()
 	cc, sc := pipe.Conn1(), pipe.Conn2()
 	// write headers and part1 body
-	if _, err := cc.Write([]byte(fmt.Sprintf("POST /foo2 HTTP/1.1\r\nHost: aaa.com\r\nContent-Length: %d\r\nContent-Type: aa\r\n\r\n", contentLength))); err != nil {
+	if _, err := fmt.Fprintf(cc, "POST /foo2 HTTP/1.1\r\nHost: aaa.com\r\nContent-Length: %d\r\nContent-Type: aa\r\n\r\n", contentLength); err != nil {
 		t.Fatal(err)
 	}
 	if _, err := cc.Write([]byte(part1)); err != nil {
@@ -3829,7 +3829,7 @@ func TestStreamRequestBodyExceedMaxSize(t *testing.T) {
 	pipe := fasthttputil.NewPipeConns()
 	cc, sc := pipe.Conn1(), pipe.Conn2()
 	// write headers and part1 body
-	if _, err := cc.Write([]byte(fmt.Sprintf("POST /foo2 HTTP/1.1\r\nHost: aaa.com\r\nContent-Length: %d\r\nContent-Type: aa\r\n\r\n%s", contentLength, part1))); err != nil {
+	if _, err := fmt.Fprintf(cc, "POST /foo2 HTTP/1.1\r\nHost: aaa.com\r\nContent-Length: %d\r\nContent-Type: aa\r\n\r\n%s", contentLength, part1); err != nil {
 		t.Error(err)
 	}
 
@@ -3876,7 +3876,7 @@ func TestStreamBodyRequestContentLength(t *testing.T) {
 
 	pipe := fasthttputil.NewPipeConns()
 	cc, sc := pipe.Conn1(), pipe.Conn2()
-	if _, err := cc.Write([]byte(fmt.Sprintf("POST /foo2 HTTP/1.1\r\nHost: aaa.com\r\nContent-Length: %d\r\nContent-Type: aa\r\n\r\n%s", contentLength, content))); err != nil {
+	if _, err := fmt.Fprintf(cc, "POST /foo2 HTTP/1.1\r\nHost: aaa.com\r\nContent-Length: %d\r\nContent-Type: aa\r\n\r\n%s", contentLength, content); err != nil {
 		t.Fatal(err)
 	}