internal/http/client.go

@@ -19,6 +19,15 @@ type OAuthTokenSourceCreator interface {
 	CreateOAuth2TokenSource(ctx context.Context) (oauth2.TokenSource, error)
 }
 
+// BytesBufferReadCloser allows direct access to the underlying buffer
+// so that re-reading ops do not incur a performance penalty.
+type BytesBufferReadCloser struct {
+	*bytes.Buffer
+}
+
+// Close is no-op - avoids http.NewRequest wrapping the body in an io.NopCloser
+func (BytesBufferReadCloser) Close() error { return nil }
+
 // retryableAuthTransport wraps a http.RoundTripper and combines it with an OAuthTokenSourceCreator so
 // that any 401s cause a re-authentication and request retry
 type retryableAuthTransport struct {
@@ -97,16 +106,26 @@ func (t *retryableAuthTransport) RoundTrip(req *http.Request) (*http.Response, e
 
 func backupRequestBody(req *http.Request) error {
 	if req.Body != nil && req.GetBody == nil {
-		bodyBytes, err := io.ReadAll(req.Body)
-		ios.Close(req.Body) // Ensure the body is always closed
-		if err != nil {
-			return err
-		}
+		// TODO handle bytes.Reader and strings.Reader
+		// optimization - we can re-read bytes.Buffer over and over again
+		if r, ok := req.Body.(BytesBufferReadCloser); ok {
+			buf := r.Buffer
+			req.GetBody = func() (io.ReadCloser, error) {
+				return BytesBufferReadCloser{buf}, nil
+			}
+			req.Body, _ = req.GetBody()
+		} else {
+			bodyBytes, err := io.ReadAll(req.Body)
+			ios.Close(req.Body) // Ensure the body is always closed
+			if err != nil {
+				return err
+			}
 
-		req.GetBody = func() (io.ReadCloser, error) {
-			return io.NopCloser(bytes.NewBuffer(bodyBytes)), nil
+			req.GetBody = func() (io.ReadCloser, error) {
+				return io.NopCloser(bytes.NewBuffer(bodyBytes)), nil
+			}
+			req.Body, _ = req.GetBody()
 		}
-		req.Body, _ = req.GetBody()
 	}
 	return nil
 }

internal/http/client_test.go

@@ -1,6 +1,7 @@
 package http_test
 
 import (
+	"bytes"
 	"context"
 	"github.com/cloudfoundry-community/go-cfclient/v3/internal/http"
 	"github.com/cloudfoundry-community/go-cfclient/v3/testutil"
@@ -32,12 +33,13 @@ func (ts *MockedOAuthTokenSource) Token() (*oauth2.Token, error) {
 }
 
 func TestOAuthSessionManager(t *testing.T) {
+	g := testutil.NewObjectJSONGenerator(1)
 	serverURL := testutil.SetupMultiple([]testutil.MockRoute{
 		{
-			Method:    "GET",
+			Method:    "POST",
 			Endpoint:  "/v3/organizations",
-			Output:    []string{"organizations[]"},
-			Statuses:  []int{200},
+			Output:    []string{"auth error", g.Organization().JSON},
+			Statuses:  []int{401, 201},
 			UserAgent: "Go-http-client/1.1",
 		},
 		{
@@ -65,14 +67,15 @@ func TestOAuthSessionManager(t *testing.T) {
 	client, err := http.NewAuthenticatedClient(context.Background(), gohttp.DefaultClient, tokenSrcCreator)
 	require.NoError(t, err)
 
-	resp, err := client.Get(serverURL + "/v3/organizations")
+	body := http.BytesBufferReadCloser{Buffer: bytes.NewBufferString(g.Organization().JSON)}
+	resp, err := client.Post(serverURL+"/v3/organizations", "application/json", body)
 	require.NoError(t, err)
-	require.Equal(t, 200, resp.StatusCode)
+	require.Equal(t, 201, resp.StatusCode)
 
 	// to the caller the retry is transparent on 401
 	resp, err = client.Get(serverURL + "/v3/spaces")
 	require.NoError(t, err)
 	require.Equal(t, 200, resp.StatusCode)
 
-	tokenSrcCreator.AssertNumberOfCalls(t, "CreateOAuth2TokenSource", 2)
+	tokenSrcCreator.AssertNumberOfCalls(t, "CreateOAuth2TokenSource", 3)
 }

internal/http/request.go

@@ -57,5 +57,7 @@ func EncodeBody(obj any) (io.Reader, error) {
 	if err := json.NewEncoder(buf).Encode(obj); err != nil {
 		return nil, fmt.Errorf("error encoding object to JSON: %w", err)
 	}
-	return buf, nil
+	return &BytesBufferReadCloser{
+		buf,
+	}, nil
 }

testutil/api_mock.go

@@ -115,14 +115,18 @@ func SetupMultiple(mockEndpoints []MockRoute, t *testing.T) string {
 				return status, singleOutput
 			})
 		case "POST":
+			count := 0
 			r.Post(endpoint, func(res http.ResponseWriter, req *http.Request) (int, string) {
 				testUserAgent(req.Header.Get("User-Agent"), userAgent, t)
 				testQueryString(req.URL.RawQuery, queryString, t)
 				testReqBody(req, postFormBody, t)
 				if redirectLocation != "" {
 					res.Header().Add("Location", redirectLocation)
 				}
-				return status, output[0]
+				singleOutput := output[count]
+				status = statuses[count]
+				count++
+				return status, singleOutput
 			})
 		case "DELETE":
 			r.Delete(endpoint, func(res http.ResponseWriter, req *http.Request) (int, string) {