queue: extend getters/setters unit tests

Add tests for the setters and getters in queue.rs and queue_sync.rs.
Add an implementation for testing for PartialEq of Queue errors.

Signed-off-by: Andreea Florescu <[email protected]>

Author: andreeaflorescu

coverage_config_x86_64.json

@@ -1,5 +1,5 @@
 {
-  "coverage_score": 87.2,
+  "coverage_score": 88.5,
   "exclude_path": "crates/virtio-bindings,crates/virtio-queue/src/mock.rs",
   "crate_features": "virtio-blk/backend-stdio"
 }

crates/virtio-queue-ser/src/state.rs

@@ -140,6 +140,6 @@ mod tests {
 
         let queue_state = QueueState::from(&queue_ser);
         let err = Queue::try_from(queue_state).unwrap_err();
-        assert_eq!(err.to_string(), Error::InvalidSize.to_string());
+        assert_eq!(err, Error::InvalidSize);
     }
 }

crates/virtio-queue/src/queue.rs

@@ -773,6 +773,15 @@ where
     }
 }
 
+#[cfg(any(test, feature = "test-utils"))]
+// It is convenient for tests to implement `PartialEq`, but it is not a
+// proper implementation as `GuestMemory` errors cannot implement `PartialEq`.
+impl PartialEq for Error {
+    fn eq(&self, other: &Self) -> bool {
+        format!("{}", &self) == format!("{}", other)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -1408,4 +1417,35 @@ mod tests {
 
         assert!(q.pop_descriptor_chain(m).is_none());
     }
+
+    #[test]
+    fn test_setters_error_cases() {
+        assert_eq!(Queue::new(15).unwrap_err(), Error::InvalidMaxSize);
+        let mut q = Queue::new(16).unwrap();
+
+        let expected_val = q.desc_table.0;
+        assert_eq!(
+            q.try_set_desc_table_address(GuestAddress(0xf)).unwrap_err(),
+            Error::InvalidDescTableAlign
+        );
+        assert_eq!(q.desc_table(), expected_val);
+
+        let expected_val = q.avail_ring.0;
+        assert_eq!(
+            q.try_set_avail_ring_address(GuestAddress(0x1)).unwrap_err(),
+            Error::InvalidAvailRingAlign
+        );
+        assert_eq!(q.avail_ring(), expected_val);
+
+        let expected_val = q.used_ring.0;
+        assert_eq!(
+            q.try_set_used_ring_address(GuestAddress(0x3)).unwrap_err(),
+            Error::InvalidUsedRingAlign
+        );
+        assert_eq!(q.used_ring(), expected_val);
+
+        let expected_val = q.size;
+        assert_eq!(q.try_set_size(15).unwrap_err(), Error::InvalidSize);
+        assert_eq!(q.size(), expected_val)
+    }
 }

crates/virtio-queue/src/queue_sync.rs

@@ -316,14 +316,17 @@ mod tests {
         let mut q = QueueSync::new(0x100).unwrap();
 
         q.set_desc_table_address(Some(0x1000), None);
+        assert_eq!(q.desc_table(), 0x1000);
         q.set_avail_ring_address(Some(0x2000), None);
+        assert_eq!(q.avail_ring(), 0x2000);
         q.set_used_ring_address(Some(0x3000), None);
+        assert_eq!(q.used_ring(), 0x3000);
         q.set_ready(true);
         assert!(q.is_valid(mem));
 
         let used_addr = GuestAddress(q.lock_state().used_ring());
 
-        assert!(!q.lock_state().event_idx_enabled());
+        assert!(!q.event_idx_enabled());
         q.enable_notification(mem).unwrap();
         let v = m.read_obj::<u16>(used_addr).map(u16::from_le).unwrap();
         assert_eq!(v, 0);