Add test for signed entity type discriminant ordering

mithril-common/src/entities/signed_entity_type.rs

@@ -26,6 +26,7 @@ const ENTITY_TYPE_CARDANO_TRANSACTIONS: usize = 3;
 /// are identified by their discriminant (i.e. index in the enum), thus the
 /// modification of this type should only ever consist of appending new
 /// variants.
+// Important note: The order of the variants is important as it is used for the derived Ord trait.
 #[derive(Display, Debug, Clone, PartialEq, Eq, Serialize, Deserialize, EnumDiscriminants)]
 #[strum(serialize_all = "PascalCase")]
 #[strum_discriminants(derive(EnumString, AsRefStr, Serialize, Deserialize, PartialOrd, Ord))]
@@ -162,4 +163,56 @@ impl SignedEntityTypeDiscriminants {
 }
 
 #[cfg(test)]
-mod tests {}
+mod tests {
+    use super::*;
+
+    // Expected ord:
+    // MithrilStakeDistribution < CardanoStakeDistribution < CardanoImmutableFilesFull < CardanoTransactions
+    #[test]
+    fn ordering_discriminant() {
+        let mut list = vec![
+            SignedEntityTypeDiscriminants::CardanoStakeDistribution,
+            SignedEntityTypeDiscriminants::CardanoTransactions,
+            SignedEntityTypeDiscriminants::CardanoImmutableFilesFull,
+            SignedEntityTypeDiscriminants::MithrilStakeDistribution,
+        ];
+        list.sort();
+
+        assert_eq!(
+            list,
+            vec![
+                SignedEntityTypeDiscriminants::MithrilStakeDistribution,
+                SignedEntityTypeDiscriminants::CardanoStakeDistribution,
+                SignedEntityTypeDiscriminants::CardanoImmutableFilesFull,
+                SignedEntityTypeDiscriminants::CardanoTransactions,
+            ]
+        );
+    }
+
+    #[test]
+    fn ordering_discriminant_with_duplicate() {
+        let mut list = vec![
+            SignedEntityTypeDiscriminants::CardanoStakeDistribution,
+            SignedEntityTypeDiscriminants::MithrilStakeDistribution,
+            SignedEntityTypeDiscriminants::CardanoTransactions,
+            SignedEntityTypeDiscriminants::CardanoStakeDistribution,
+            SignedEntityTypeDiscriminants::CardanoImmutableFilesFull,
+            SignedEntityTypeDiscriminants::MithrilStakeDistribution,
+            SignedEntityTypeDiscriminants::MithrilStakeDistribution,
+        ];
+        list.sort();
+
+        assert_eq!(
+            list,
+            vec![
+                SignedEntityTypeDiscriminants::MithrilStakeDistribution,
+                SignedEntityTypeDiscriminants::MithrilStakeDistribution,
+                SignedEntityTypeDiscriminants::MithrilStakeDistribution,
+                SignedEntityTypeDiscriminants::CardanoStakeDistribution,
+                SignedEntityTypeDiscriminants::CardanoStakeDistribution,
+                SignedEntityTypeDiscriminants::CardanoImmutableFilesFull,
+                SignedEntityTypeDiscriminants::CardanoTransactions,
+            ]
+        );
+    }
+}