test(copy_file_range): assert TRANSFER_CLASSIFIED copied byte count end-to-end

TestCopyFileRangeBasic previously asserted only the enter event and source
path (copyrangesrc.txt) but not the copied byte count on the
TRANSFER_CLASSIFIED exit, unlike sibling sendfile64/splice/tee coverage in
retbytes_test.go. The basic scenario copies exactly the 32-byte payload
"copy_file_range integration data" in a single copy_file_range(2) call, so
the exit byte count is deterministic.

Switch to runScenarioResult and add assertEventBytesEqual(...,32) plus
assertEventDurationPositive to lock in the transfer attribution (FamilyFS,
fd_in@args[0], ret TransferClassified). Coverage hardening only; no defect.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/integrationtests/copy_file_range_test.go b/integrationtests/copy_file_range_test.go
index d87c5af..b8e81a6 100644
--- a/integrationtests/copy_file_range_test.go
+++ b/integrationtests/copy_file_range_test.go
@@ -3,7 +3,7 @@ package integrationtests
 import "testing"
 
 func TestCopyFileRangeBasic(t *testing.T) {
-	runScenario(t, "copy-file-range-basic", []ExpectedEvent{
+	result, _ := runScenarioResult(t, "copy-file-range-basic", []ExpectedEvent{
 		{
 			PathContains: "copyrangesrc.txt",
 			Tracepoint:   "enter_copy_file_range",
@@ -11,6 +11,16 @@ func TestCopyFileRangeBasic(t *testing.T) {
 			MinCount:     1,
 		},
 	})
+
+	// copy_file_range is TRANSFER_CLASSIFIED: a successful call reports
+	// ctx->ret > 0, the number of bytes copied from fd_in to fd_out. The
+	// basic scenario copies exactly the 32-byte payload
+	// ("copy_file_range integration data") in a single call, so the exit
+	// byte count is deterministic and must equal 32. Locking in the exact
+	// count guards the transfer attribution (FamilyFS, fd_in@args[0]).
+	exp := ExpectedEvent{Tracepoint: "enter_copy_file_range", Comm: "ioworkload"}
+	assertEventBytesEqual(t, result, exp, 32)
+	assertEventDurationPositive(t, result, exp)
 }
 
 func TestCopyFileRangeBadDstFd(t *testing.T) {