Function TestDialErrorBodyRetry

modules/caddyhttp/reverseproxy/retries_test.go:140–260

TestDialErrorBodyRetry verifies that a POST request whose body has NOT been pre-buffered via request_buffers can still be retried after a dial error. Before the fix, a dial error caused Go's transport to close the shared body (via cloneRequest's shallow copy), so the retry attempt would read from a

(t *testing.T)

// shared body. Since dial errors never read any bytes, the body remains at
// position 0 for the retry.
func TestDialErrorBodyRetry(t *testing.T) {
	// Good upstream: echoes the request body with 200 OK.
	goodServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		body, err := io.ReadAll(r.Body)
		if err != nil {
			http.Error(w, "read body: "+err.Error(), http.StatusInternalServerError)
			return
		}
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write(body)
	}))
	t.Cleanup(goodServer.Close)

	const requestBody = "hello, retry"

	tests := []struct {
		name       string
		method     string
		body       string
		retries    int
		wantStatus int
		wantBody   string
	}{
		{
			// Core regression case: POST with a body, no request_buffers,
			// dial error on first upstream → retry to second upstream succeeds.
			name:       "POST body retried after dial error",
			method:     http.MethodPost,
			body:       requestBody,
			retries:    1,
			wantStatus: http.StatusOK,
			wantBody:   requestBody,
		},
		{
			// Dial errors are always retried regardless of method, but there
			// is no body to re-read, so GET has always worked. Keep it as a
			// sanity check that we did not break the no-body path.
			name:       "GET without body retried after dial error",
			method:     http.MethodGet,
			body:       "",
			retries:    1,
			wantStatus: http.StatusOK,
			wantBody:   "",
		},
		{
			// Without any retry configuration the handler must give up on the
			// first dial error and return a 502. Confirms no wrapping occurs
			// in the no-retry path.
			name:       "no retries configured returns 502 on dial error",
			method:     http.MethodPost,
			body:       requestBody,
			retries:    0,
			wantStatus: http.StatusBadGateway,
			wantBody:   "",
		},
	}

	for _, tc := range tests {