1 files changed, 81 insertions, 0 deletions
diff --git a/internal/eventloop_mountfs_test.go b/internal/eventloop_mountfs_test.go
new file mode 100644
index 0000000..05c11d9
--- /dev/null
+++ b/internal/eventloop_mountfs_test.go
@@ -0,0 +1,81 @@
+package internal
+
+import (
+	"testing"
+
+	"ior/internal/event"
+	"ior/internal/file"
+	"ior/internal/globalfilter"
+	"ior/internal/types"
+)
+
+func TestHandleTwoFdExitUsesFirstDescriptor(t *testing.T) {
+	el := mustNewEventLoop(t, eventLoopConfig{})
+	el.fdState().set(81, file.NewFd(81, "/proc/self/fd/81", -1))
+
+	enter := &types.TwoFdEvent{
+		EventType: types.ENTER_TWO_FD_EVENT,
+		TraceId:   types.SYS_ENTER_MOVE_MOUNT,
+		Time:      100,
+		Pid:       70,
+		Tid:       71,
+		FdA:       81,
+		FdB:       82,
+		Extra:     0x2,
+	}
+	exit := &types.RetEvent{
+		EventType: types.EXIT_RET_EVENT,
+		TraceId:   types.SYS_EXIT_MOVE_MOUNT,
+		Time:      200,
+		Ret:       0,
+		Pid:       70,
+		Tid:       71,
+	}
+	ep := &event.Pair{EnterEv: enter, ExitEv: exit}
+
+	if ok := el.handleTwoFdExit(ep, enter); !ok {
+		t.Fatal("handleTwoFdExit returned false")
+	}
+	if ep.File == nil || ep.File.FD() != 81 {
+		t.Fatalf("expected resolved descriptor 81, got file=%v", ep.File)
+	}
+}
+
+func TestHandleTwoFdExitAppliesPairFilter(t *testing.T) {
+	el := mustNewEventLoop(t, eventLoopConfig{
+		filter: globalfilter.Filter{
+			Syscall: &globalfilter.StringFilter{Pattern: "openat"},
+		},
+	})
+
+	enter := &types.TwoFdEvent{
+		EventType: types.ENTER_TWO_FD_EVENT,
+		TraceId:   types.SYS_ENTER_MOVE_MOUNT,
+		Time:      100,
+		Pid:       72,
+		Tid:       73,
+		FdA:       91,
+		FdB:       92,
+		Extra:     0,
+	}
+	exit := &types.RetEvent{
+		EventType: types.EXIT_RET_EVENT,
+		TraceId:   types.SYS_EXIT_MOVE_MOUNT,
+		Time:      200,
+		Ret:       0,
+		Pid:       72,
+		Tid:       73,
+	}
+	ep := &event.Pair{EnterEv: enter, ExitEv: exit}
+
+	if ok := el.handleTwoFdExit(ep, enter); ok {
+		t.Fatal("handleTwoFdExit should reject pair due to filter mismatch")
+	}
+}
+
+func TestInitRawHandlersRegistersTwoFdEvent(t *testing.T) {
+	el := mustNewEventLoop(t, eventLoopConfig{})
+	if _, ok := el.rawHandlers[types.ENTER_TWO_FD_EVENT]; !ok {
+		t.Fatal("ENTER_TWO_FD_EVENT handler is not registered")
+	}
+}