Support currencies in openleadr-wire (#54)

Cargo.toml

@@ -63,3 +63,5 @@ argon2 = "0.5.3"
 dotenvy = "0.15.7"
 
 serial_test = "3.1.1"
+
+iso_currency = { version = "0.5.0", features = ["with-serde"] }

openleadr-wire/Cargo.toml

@@ -19,6 +19,7 @@ iso8601-duration.workspace = true
 thiserror.workspace = true
 http.workspace = true
 validator.workspace = true
+iso_currency.workspace = true
 
 [dev-dependencies]
 serde_json.workspace = true

openleadr-wire/src/event.rs

@@ -5,6 +5,7 @@ use crate::{
     values_map::Value, Identifier, IdentifierError, Unit,
 };
 use chrono::{DateTime, Utc};
+use iso_currency::Currency;
 use serde::{Deserialize, Serialize};
 use serde_with::skip_serializing_none;
 use std::{
@@ -208,13 +209,6 @@ impl EventPayloadDescriptor {
     }
 }
 
-// TODO: Find a nice ISO 4217 crate
-/// A currency described as listed in ISO 4217
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub enum Currency {
-    Todo,
-}
-
 /// An object defining a temporal window and a list of valuesMaps. if intervalPeriod present may set
 /// temporal aspects of interval or override event.intervalPeriod.
 #[skip_serializing_none]
@@ -428,4 +422,35 @@ mod tests {
             expected
         );
     }
+
+    #[test]
+    fn test_currency() {
+        // deserialize
+        let example = r#"{"payloadType":"SIMPLE","currency":"EUR"}"#;
+
+        let expected = EventPayloadDescriptor {
+            payload_type: EventType::Simple,
+            units: None,
+            currency: Some(Currency::EUR),
+        };
+
+        assert_eq!(
+            serde_json::from_str::<EventPayloadDescriptor>(example).unwrap(),
+            expected
+        );
+
+        // round-trip
+        let source = EventPayloadDescriptor {
+            payload_type: EventType::Price,
+            units: Some(Unit::Volts),
+            currency: Some(Currency::USD),
+        };
+
+        let serialized = serde_json::to_string(&source).unwrap();
+
+        assert_eq!(
+            source,
+            serde_json::from_str::<EventPayloadDescriptor>(&serialized).unwrap()
+        );
+    }
 }