Support for unit enum desr

src/de/variant_de.rs

@@ -1,5 +1,8 @@
 use crate::{de::wbem_class_de::Deserializer, variant::Variant, WMIError};
-use serde::{de, forward_to_deserialize_any, Deserialize};
+use serde::{
+    de::{self, IntoDeserializer},
+    forward_to_deserialize_any, Deserialize,
+};
 use std::{fmt, vec::IntoIter};
 
 #[derive(Debug)]
@@ -84,16 +87,19 @@ impl<'de> serde::Deserializer<'de> for Variant {
     fn deserialize_enum<V>(
         self,
         name: &'static str,
-        fields: &'static [&'static str],
+        variants: &'static [&'static str],
         visitor: V,
     ) -> Result<V::Value, Self::Error>
     where
         V: de::Visitor<'de>,
     {
         match self {
             Variant::Object(o) => {
-                Deserializer::from_wbem_class_obj(o).deserialize_enum(name, fields, visitor)
+                Deserializer::from_wbem_class_obj(o).deserialize_enum(name, variants, visitor)
             }
+            Variant::String(str) => str
+                .into_deserializer()
+                .deserialize_enum(name, variants, visitor),
             _ => self.deserialize_any(visitor),
         }
     }

src/de/wbem_class_de.rs

@@ -487,4 +487,49 @@ mod tests {
 
         assert!(matches!(proc.TargetInstance, Instance::Process(..)))
     }
+
+    #[test]
+    fn it_can_desr_unit_enum_field_from_string() {
+        let wmi_con = wmi_con();
+
+        #[derive(Deserialize, Debug, PartialEq, Eq)]
+        enum Status {
+            SomeValue,
+            OK,
+            SomeOtherValue,
+        }
+
+        #[derive(Deserialize, Debug)]
+        struct Win32_OperatingSystem {
+            Status: Status,
+        }
+
+        let os: Win32_OperatingSystem = wmi_con.get().unwrap();
+
+        assert_eq!(os.Status, Status::OK);
+    }
+
+    #[test]
+    fn it_fail_to_desr_unit_enum_field_from_unexpected_string() {
+        let wmi_con = wmi_con();
+
+        #[derive(Deserialize, Debug, PartialEq, Eq)]
+        enum Status {
+            Potato,
+        }
+
+        #[derive(Deserialize, Debug)]
+        struct Win32_OperatingSystem {
+            Status: Status,
+        }
+
+        let res: Result<Win32_OperatingSystem, WMIError> = wmi_con.get();
+
+        let err = res.err().unwrap();
+
+        assert_eq!(
+            format!("{}", err),
+            "unknown variant `OK`, expected `Potato`"
+        )
+    }
 }