test(rdpeusb): add client/server I/O sequence coverage

crates/ironrdp-rdpeusb/src/client.rs

@@ -215,7 +215,7 @@ pub trait UrbdrcDeviceBackend: Send {
     /// the message MUST match the RequestId in the QUERY_DEVICE_TEXT message.
     ///
     /// [3.3.5.3.5]: https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpeusb/834f56cc-cfed-4649-8952-0b6486638c28
-    fn query_device_text(&mut self, channel_id: u32, text_type: u32, locale_id: u32) -> PduResult<Option<DeviceText>>;
+    fn query_device_text(&mut self, channel_id: u32, text_type: u32, locale_id: u32) -> PduResult<DeviceText>;
 
     /// Process an `IoControl` request.
     ///
@@ -550,19 +550,15 @@ impl DvcProcessor for UrbdrcDeviceClient {
                 if !self.ready_for_io || dev_text_pdu.udev_iface != self.udev_iface {
                     return Ok(Vec::new());
                 }
-                if let Some(device_text) =
+                let device_text =
                     self.backend
-                        .query_device_text(channel_id, dev_text_pdu.text_type, dev_text_pdu.locale_id)?
-                {
-                    Ok(vec![Box::new(QueryDeviceTextRsp {
-                        msg_id: dev_text_pdu.msg_id,
-                        udev_iface: dev_text_pdu.udev_iface,
-                        hresult: device_text.hresult,
-                        device_description: device_text.description.into(),
-                    })])
-                } else {
-                    Ok(Vec::new())
-                }
+                        .query_device_text(channel_id, dev_text_pdu.text_type, dev_text_pdu.locale_id)?;
+                Ok(vec![Box::new(QueryDeviceTextRsp {
+                    msg_id: dev_text_pdu.msg_id,
+                    udev_iface: dev_text_pdu.udev_iface,
+                    hresult: device_text.hresult,
+                    device_description: device_text.description.into(),
+                })])
             }
             IoCtl(io_ctl_pdu) => {
                 if !self.ready_for_io || io_ctl_pdu.udev_iface != self.udev_iface {

crates/ironrdp-testsuite-core/tests/rdpeusb/client.rs

@@ -18,17 +18,7 @@ use ironrdp_rdpeusb::pdu::{
     UrbdrcClientControlPdu, UrbdrcClientDevicePdu, UrbdrcServerControlPdu, UrbdrcServerDevicePdu,
 };
 
-use super::simple_device_info;
-
-const STREAM_ID_PROXY: u32 = 1;
-
-fn proxy_iface_id(iface: InterfaceId) -> u32 {
-    u32::from(iface) | (STREAM_ID_PROXY << 30)
-}
-
-fn encode_pdu<T: ironrdp_core::Encode>(pdu: &T) -> Vec<u8> {
-    encode_vec(pdu).expect("encode should succeed")
-}
+use super::{encode_pdu, proxy_iface_id, simple_device_info};
 
 fn decode_control_msg(message: &DvcMessage) -> UrbdrcClientControlPdu {
     let encoded = encode_vec(message.as_ref()).expect("encode should succeed");
@@ -98,13 +88,11 @@ impl UrbdrcDeviceBackend for TestDeviceBackend {
 
     fn cancel_request(&mut self, _request_id: RequestId, _channel_id: u32) {}
 
-    fn query_device_text(
-        &mut self,
-        _channel_id: u32,
-        _text_type: u32,
-        _locale_id: u32,
-    ) -> PduResult<Option<DeviceText>> {
-        Ok(None)
+    fn query_device_text(&mut self, _channel_id: u32, _text_type: u32, _locale_id: u32) -> PduResult<DeviceText> {
+        Ok(DeviceText {
+            hresult: 0,
+            description: String::new(),
+        })
     }
 
     fn io_control(