Make Request implement io.WriterTo

client.go

@@ -153,7 +153,7 @@ func (c *Client) do(ctx context.Context, conn net.Conn, req *Request) (*Response
 	}
 
 	// Write the request
-	if err := req.Write(w); err != nil {
+	if _, err := req.WriteTo(w); err != nil {
 		return nil, err
 	}
 

request.go

@@ -77,21 +77,26 @@ func ReadRequest(r io.Reader) (*Request, error) {
 	return &Request{URL: u}, nil
 }
 
-// Write writes a Gemini request in wire format.
+// WriteTo writes r to w in the Gemini request format.
 // This method consults the request URL only.
-func (r *Request) Write(w io.Writer) error {
+func (r *Request) WriteTo(w io.Writer) (int, error) {
 	bw := bufio.NewWriterSize(w, 1026)
 	url := r.URL.String()
 	if len(url) > 1024 {
-		return ErrInvalidRequest
+		return 0, ErrInvalidRequest
 	}
-	if _, err := bw.WriteString(url); err != nil {
-		return err
+	var wrote int
+	n, err := bw.WriteString(url)
+	wrote += n
+	if err != nil {
+		return wrote, err
 	}
-	if _, err := bw.Write(crlf); err != nil {
-		return err
+	n, err = bw.Write(crlf)
+	wrote += n
+	if err != nil {
+		return wrote, err
 	}
-	return bw.Flush()
+	return wrote, bw.Flush()
 }
 
 // Conn returns the network connection on which the request was received.

request_test.go

@@ -119,7 +119,7 @@ func TestWriteRequest(t *testing.T) {
 		t.Logf("%s", test.Req.URL)
 		var b strings.Builder
 		bw := bufio.NewWriter(&b)
-		err := test.Req.Write(bw)
+		_, err := test.Req.WriteTo(bw)
 		if err != test.Err {
 			t.Errorf("expected err = %v, got %v", test.Err, err)
 		}