2 files changed, 20 insertions, 25 deletions

diff --git a/client/client.go b/client/client.go
index b68b2be..60d4461 100644
--- a/client/client.go
+++ b/client/client.go
@@ -3,7 +3,6 @@
 package client
 
 import (
-	"bytes"
 	"fmt"
 	"io"
 	"net/http"
@@ -20,28 +19,28 @@ type CaesarClient struct {
 	once sync.Once
 }
 
-// EncodeMessage asks the Caesar server to encode the supplied message and
-// returns the result along with an error in case the request fails.
-func (c *CaesarClient) EncodeMessage(r io.Reader) (io.Reader, error) {
+// EncodeMessage asks the Caesar server to encode the supplied message, writes
+// the encoded message to the supplied writer, and returns an error in case the
+// request fails.
+func (c *CaesarClient) EncodeMessage(w io.Writer, r io.Reader) error {
 	c.once.Do(func() {
 		c.c = &http.Client{Timeout: 10 * time.Second}
 	})
 	req, err := http.NewRequest("POST", c.Endpoint, r)
 	if err != nil {
-		return nil, err
+		return err
 	}
 	req.Header.Set("user-agent", "caesar-client/1.0")
 	resp, err := c.c.Do(req)
 	if err != nil {
-		return nil, err
+		return err
 	}
 	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("http status %s", resp.Status)
+		return fmt.Errorf("http status %s", resp.Status)
 	}
-	var body bytes.Buffer
 	defer resp.Body.Close()
-	if _, err := io.Copy(&body, resp.Body); err != nil {
-		return nil, err
+	if _, err := io.Copy(w, resp.Body); err != nil {
+		return err
 	}
-	return &body, nil
+	return nil
 }
diff --git a/client/client_test.go b/client/client_test.go
index a724857..bfb8480 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -1,6 +1,7 @@
 package client
 
 import (
+	"bytes"
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
@@ -14,32 +15,27 @@ func TestEncode(t *testing.T) {
 	}))
 	defer server.Close()
 	client := CaesarClient{Endpoint: server.URL} // HL
-	r, err := client.EncodeMessage(strings.NewReader("secret message"))
-	if err != nil {
+	var b bytes.Buffer
+	if err := client.EncodeMessage(&b, strings.NewReader("secret message")); err != nil {
 		t.Errorf("should not have gotten error: %v", err)
 	}
-	if r == nil {
-		t.Fatalf("should have gotten a reader")
-	}
-	resp, err := ioutil.ReadAll(r)
-	if err != nil {
-		t.Fatalf("could not read message: %v", err)
-	}
-	if string(resp) != "response" {
+	resp := b.String()
+	if resp != "response" {
 		t.Errorf("expected 'response' but got '%s'", resp)
 	}
 }
 
 func TestUserAgent(t *testing.T) {
 	var ua string
-	var hf http.HandlerFunc = func(w http.ResponseWriter, r *http.Request) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		ua = r.Header.Get("user-agent")
-	}
-	server := httptest.NewServer(hf)
+	}))
 	defer server.Close()
 
 	c := CaesarClient{Endpoint: server.URL}
-	c.EncodeMessage(strings.NewReader("secret message"))
+	if err := c.EncodeMessage(ioutil.Discard, strings.NewReader("secret message")); err != nil {
+		t.Errorf("expected no error but got %v", err)
+	}
 
 	expected := "caesar-client/1.0"
 	if ua != expected {