fix: allow deserialization of optional decimals (#139)

the 'rust_decimal::serde::arbitrary_precision_option' macro
requires 'default' to be specified to allow deserializing
the objects when the value is not present

Author: j-white

src/tests/schema_validation/v2_0_1.rs

@@ -2226,6 +2226,113 @@ mod tests {
         }
         assert!(compiled.is_valid(&instance));
     }
+    /**
+     * Some optional fields including maxLimit of the VariableCharacteristicsType are not
+     * included in the payload in order to validate deserialization of optional fields.
+     */
+    #[test]
+    fn validate_notify_report_request_from_json() {
+        let json = r#"{
+    "generatedAt": "2024-12-23T03:38:31.625Z",
+    "reportData": [
+      {
+        "component": {
+          "name": "AlignedDataCtrlr"
+        },
+        "variable": {
+          "name": "Interval"
+        },
+        "variableAttribute": [
+          {
+            "mutability": "ReadWrite",
+            "value": "10"
+          }
+        ],
+        "variableCharacteristics": {
+          "dataType": "integer",
+          "supportsMonitoring": true,
+          "unit": "seconds"
+        }
+      },
+      {
+        "component": {
+          "name": "AlignedDataCtrlr"
+        },
+        "variable": {
+          "name": "Measurands"
+        },
+        "variableAttribute": [
+          {
+            "mutability": "ReadWrite",
+            "value": "Energy.Active.Import.Register"
+          }
+        ],
+        "variableCharacteristics": {
+          "dataType": "MemberList",
+          "supportsMonitoring": true
+        }
+      },
+      {
+        "component": {
+          "name": "AlignedDataCtrlr"
+        },
+        "variable": {
+          "name": "TxEndedInterval"
+        },
+        "variableAttribute": [
+          {
+            "mutability": "ReadWrite",
+            "value": "10"
+          }
+        ],
+        "variableCharacteristics": {
+          "dataType": "integer",
+          "supportsMonitoring": true,
+          "unit": "seconds"
+        }
+      },
+      {
+        "component": {
+          "name": "AlignedDataCtrlr"
+        },
+        "variable": {
+          "name": "TxEndedMeasurands"
+        },
+        "variableAttribute": [
+          {
+            "mutability": "ReadWrite",
+            "value": "Energy.Active.Import.Register"
+          }
+        ],
+        "variableCharacteristics": {
+          "dataType": "MemberList",
+          "supportsMonitoring": true,
+          "minLimit": 0
+        }
+      }
+    ],
+    "requestId": 1,
+    "seqNo": 0,
+    "tbc": true
+  }"#;
+
+        // verify that the JSON can be deserialized into a NotifyReportRequest object
+        let request: NotifyReportRequest = serde_json::from_str(json).unwrap();
+        assert_eq!(request.request_id, 1);
+
+        let schema = include_str!("schemas/v2.0.1/NotifyReportRequest.json");
+        let schema = serde_json::from_str(schema).unwrap();
+        let instance = serde_json::from_str(json).unwrap();
+        let compiled = Validator::new(&schema).expect("A valid schema");
+        let result = compiled.validate(&instance);
+        if let Err(errors) = result {
+            for error in errors {
+                println!("Validation error: {}", error);
+                println!("Instance path: {}", error.instance_path);
+            }
+        }
+        assert!(compiled.is_valid(&instance));
+    }
     #[test]
     fn validate_notify_report_request() {
         let test = NotifyReportRequest {
@@ -2257,7 +2364,7 @@ mod tests {
                     unit: Some("unit".to_string()),
                     data_type: DataEnumType::String,
                     min_limit: Some(dec!(0.0)),
-                    max_limit: Some(dec!(0.0)),
+                    max_limit: None,
                     values_list: Some("values_list".to_string()),
                     supports_monitoring: false,
                 }),

src/v1_6/types/charging_schedule.rs

@@ -18,7 +18,10 @@ pub struct ChargingSchedule {
     /// Required. List of ChargingSchedulePeriod elements defining maximum power or current usage over time. The startSchedule of the first ChargingSchedulePeriod SHALL always be 0.
     pub charging_schedule_period: Vec<ChargingSchedulePeriod>,
     /// Optional. Minimum charging rate supported by the electric vehicle. The unit of measure is defined by the chargingRateUnit. This parameter is intended to be used by a local smart charging algorithm to optimize the power allocation for in the case a charging process is inefficient at lower charging rates. Accepts at most one digit fraction (e.g. 8.1)
-    #[serde(skip_serializing_if = "Option::is_none")]
-    #[serde(with = "rust_decimal::serde::arbitrary_precision_option")]
+    #[serde(
+        with = "rust_decimal::serde::arbitrary_precision_option",
+        skip_serializing_if = "Option::is_none",
+        default
+    )]
     pub min_charging_rate: Option<Decimal>,
 }

src/v2_0_1/datatypes/charging_schedule_type.rs

@@ -23,8 +23,11 @@ pub struct ChargingScheduleType {
     /// Required. The unit of measure Limit is expressed in.
     pub charging_rate_unit: ChargingRateUnitEnumType,
     /// Optional. Minimum charging rate supported by the EV. The unit of measure is defined by the chargingRateUnit. This parameter is intended to be used by a local smart charging algorithm to optimize the power allocation for in the case a charging process is inefficient at lower charging rates. Accepts at most one digit fraction (e.g. 8.1)
-    #[serde(skip_serializing_if = "Option::is_none")]
-    #[serde(with = "rust_decimal::serde::arbitrary_precision_option")]
+    #[serde(
+        with = "rust_decimal::serde::arbitrary_precision_option",
+        skip_serializing_if = "Option::is_none",
+        default
+    )]
     pub min_charging_rate: Option<Decimal>,
     /// Required. List of ChargingSchedulePeriod elements defining maximum power or current usage over time. The maximum number of periods, that is supported by the Charging Station, if less than 1024, is set by device model variable SmartChargingCtrlr.PeriodsPerSchedule
     #[validate(length(min = 1))]

src/v2_0_1/datatypes/variable_characteristics_type.rs

@@ -10,11 +10,17 @@ pub struct VariableCharacteristicsType {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub unit: Option<String>,
     pub data_type: DataEnumType,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    #[serde(with = "rust_decimal::serde::arbitrary_precision_option")]
+    #[serde(
+        with = "rust_decimal::serde::arbitrary_precision_option",
+        skip_serializing_if = "Option::is_none",
+        default
+    )]
     pub min_limit: Option<Decimal>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    #[serde(with = "rust_decimal::serde::arbitrary_precision_option")]
+    #[serde(
+        with = "rust_decimal::serde::arbitrary_precision_option",
+        skip_serializing_if = "Option::is_none",
+        default
+    )]
     pub max_limit: Option<Decimal>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub values_list: Option<String>,

src/v2_0_1/messages/transaction_event.rs

@@ -40,8 +40,11 @@ pub struct TransactionEventRequest {
 #[derive(serde::Serialize, serde::Deserialize, Debug, Clone, PartialEq, Default)]
 #[serde(rename_all = "camelCase")]
 pub struct TransactionEventResponse {
-    #[serde(skip_serializing_if = "Option::is_none")]
-    #[serde(with = "rust_decimal::serde::arbitrary_precision_option")]
+    #[serde(
+        with = "rust_decimal::serde::arbitrary_precision_option",
+        skip_serializing_if = "Option::is_none",
+        default
+    )]
     pub total_cost: Option<Decimal>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub charging_priority: Option<i32>,