Add test for customizable resampling functions

Signed-off-by: Sahas Subramanian <sahas.subramanian@proton.me>

Author: shsms

src/logical_meter/logical_meter_handle.rs

@@ -186,6 +186,7 @@ impl LogicalMeterHandle {
 #[cfg(test)]
 mod tests {
     use chrono::TimeDelta;
+    use frequenz_resampling::ResamplingFunction;
     use tokio_stream::{StreamExt, wrappers::BroadcastStream};
 
     use crate::{
@@ -421,6 +422,57 @@ mod tests {
         )
     }
 
+    #[tokio::test(start_paused = true)]
+    async fn test_resampling_functions() {
+        let lm_config = Some(
+            LogicalMeterConfig::new(TimeDelta::try_milliseconds(200).unwrap())
+                .with_default_resampling_function(ResamplingFunction::Count)
+                .override_resampling_function::<crate::metric::AcVoltage>(ResamplingFunction::Last),
+        );
+        let mut lm = new_logical_meter_handle(lm_config).await;
+        let bat_volt_formula = lm.battery(None, crate::metric::AcVoltage).unwrap();
+
+        let samples = fetch_samples(bat_volt_formula, 10).await;
+        check_samples(
+            samples,
+            |q| q.as_volts(),
+            TimeDelta::try_milliseconds(200).unwrap(),
+            vec![
+                Some(400.0),
+                Some(400.0),
+                Some(398.0),
+                Some(396.0),
+                Some(396.0),
+                Some(396.0),
+                Some(396.0),
+                Some(396.0),
+                None,
+                None,
+            ],
+        );
+
+        let cons_pow_formula = lm.consumer(crate::metric::AcPowerActive).unwrap();
+
+        let samples = fetch_samples(cons_pow_formula, 10).await;
+        check_samples(
+            samples,
+            |q| q.as_watts(),
+            TimeDelta::try_milliseconds(200).unwrap(),
+            vec![
+                Some(1.0),
+                Some(2.0),
+                Some(3.0),
+                Some(3.0),
+                Some(3.0),
+                Some(3.0),
+                Some(2.0),
+                Some(1.0),
+                Some(0.0),
+                Some(0.0),
+            ],
+        );
+    }
+
     #[tokio::test(start_paused = true)]
     async fn test_consumer_current_formula() {
         let formula = new_logical_meter_handle(None)
@@ -478,14 +530,14 @@ mod tests {
             );
         });
 
-        for (v, ev) in values.iter().zip(expected_values.iter()) {
+        for (id, (v, ev)) in values.iter().zip(expected_values.iter()).enumerate() {
             match (v, ev) {
                 (Some(v), Some(ev)) => assert!(
                     (v - ev).abs() < 0.01,
-                    "expected value {ev:?}, got value {v:?}"
+                    "Item {id} - expected value {ev:?}, got value {v:?}"
                 ),
                 (None, None) => {}
-                _ => panic!("expected value {ev:?}, got value {v:?}"),
+                _ => panic!("Item {id} - expected value {ev:?}, got value {v:?}"),
             }
         }
     }