Added defaults to FieldType.

src/message.rs

@@ -959,6 +959,15 @@ enum FieldType {
     Uuid,
 }
 
+impl FieldType {
+    fn get_default(&self) -> Field {
+        match self {
+            FieldType::StaticString => "".into(),
+            FieldType::Uuid => Uuid::new_v4().into(),
+        }
+    }
+}
+
 impl From<&Field> for FieldType {
     fn from(value: &Field) -> Self {
         match value {
@@ -968,6 +977,37 @@ impl From<&Field> for FieldType {
     }
 }
 
+#[cfg(test)]
+mod fieldtypes {
+    use super::*;
+
+    #[test]
+    fn can_get_defaults_for_uuid() {
+        let ftype = FieldType::Uuid;
+        let mut ids: Vec<Uuid> = Vec::new();
+        for _ in 0..5 {
+            let result = ftype.get_default();
+            match result {
+                Field::Uuid(data) => {
+                    assert!(!ids.contains(&data), "found duplicate id {:?} in {:?}", data, ids);
+                    ids.push(data.clone());
+                },
+                _ => unreachable!("got {:?}: should have been uuid", result),
+            }
+        }
+    }
+
+    #[test]
+    fn can_get_defaults_for_static_string() {
+        let ftype = FieldType::StaticString;
+        let result = ftype.get_default();
+        match result {
+            Field::StaticString(data) => assert_eq!(data, ""),
+            _ => unreachable!("got {:?}: should have been static string", result),
+        }
+    }
+}
+
 #[derive(Clone, Debug, PartialEq)]
 enum Field {
     StaticString(String),