fix: Fix LossLink and WTW losses.

- Add missing aggregated nodes to LossLinkNode and
WaterTreatmentWorks. This means that actually apply losses.
- Adds a shared struct for defining Gross or Net losses.
- Add new tests for both nodes.

pywr-core/src/aggregated_node.rs

@@ -344,6 +344,6 @@ mod tests {
 
         let model = Model::new(default_time_domain().into(), network);
 
-        run_all_solvers(&model, &["cbc", "highs"]);
+        run_all_solvers(&model, &["cbc", "highs"], &[]);
     }
 }

pywr-core/src/metric.rs

@@ -27,6 +27,14 @@ impl ConstantMetricF64 {
             ConstantMetricF64::Constant(v) => Ok(*v),
         }
     }
+
+    /// Returns true if the constant value is a [`ConstantMetricF64::Constant`] with a value of zero.
+    pub fn is_constant_zero(&self) -> bool {
+        match self {
+            ConstantMetricF64::Constant(v) => *v == 0.0,
+            _ => false,
+        }
+    }
 }
 #[derive(Clone, Debug, PartialEq)]
 pub enum SimpleMetricF64 {
@@ -45,6 +53,14 @@ impl SimpleMetricF64 {
             SimpleMetricF64::Constant(m) => m.get_value(values.get_constant_values()),
         }
     }
+
+    /// Returns true if the constant value is a [`ConstantMetricF64::Constant`] with a value of zero.
+    pub fn is_constant_zero(&self) -> bool {
+        match self {
+            SimpleMetricF64::Constant(c) => c.is_constant_zero(),
+            _ => false,
+        }
+    }
 }
 
 #[derive(Clone, Debug, PartialEq)]
@@ -122,6 +138,14 @@ impl MetricF64 {
             MetricF64::Simple(s) => s.get_value(&state.get_simple_parameter_values()),
         }
     }
+
+    /// Returns true if the constant value is a [`ConstantMetricF64::Constant`] with a value of zero.
+    pub fn is_constant_zero(&self) -> bool {
+        match self {
+            MetricF64::Simple(s) => s.is_constant_zero(),
+            _ => false,
+        }
+    }
 }
 
 impl TryFrom<MetricF64> for SimpleMetricF64 {

pywr-core/src/network.rs

@@ -1785,7 +1785,7 @@ mod tests {
         model.network_mut().add_recorder(Box::new(recorder)).unwrap();
 
         // Test all solvers
-        run_all_solvers(&model, &[]);
+        run_all_solvers(&model, &[], &[]);
     }
 
     #[test]
@@ -1809,7 +1809,7 @@ mod tests {
         network.add_recorder(Box::new(recorder)).unwrap();
 
         // Test all solvers
-        run_all_solvers(&model, &[]);
+        run_all_solvers(&model, &[], &[]);
     }
 
     /// Test proportional storage derived metric.
@@ -1849,7 +1849,7 @@ mod tests {
         network.add_recorder(Box::new(recorder)).unwrap();
 
         // Test all solvers
-        run_all_solvers(&model, &[]);
+        run_all_solvers(&model, &[], &[]);
     }
 
     #[test]

pywr-core/src/recorders/csv.rs

@@ -8,6 +8,7 @@ use chrono::NaiveDateTime;
 use serde::{Deserialize, Serialize};
 use std::any::Any;
 use std::fs::File;
+use std::num::NonZeroU32;
 use std::ops::Deref;
 use std::path::PathBuf;
 
@@ -205,14 +206,21 @@ pub struct CsvLongFmtOutput {
     meta: RecorderMeta,
     filename: PathBuf,
     metric_set_indices: Vec<MetricSetIndex>,
+    decimal_places: Option<NonZeroU32>,
 }
 
 impl CsvLongFmtOutput {
-    pub fn new<P: Into<PathBuf>>(name: &str, filename: P, metric_set_indices: &[MetricSetIndex]) -> Self {
+    pub fn new<P: Into<PathBuf>>(
+        name: &str,
+        filename: P,
+        metric_set_indices: &[MetricSetIndex],
+        decimal_places: Option<NonZeroU32>,
+    ) -> Self {
         Self {
             meta: RecorderMeta::new(name),
             filename: filename.into(),
             metric_set_indices: metric_set_indices.to_vec(),
+            decimal_places,
         }
     }
 
@@ -236,14 +244,21 @@ impl CsvLongFmtOutput {
                         let name = metric.name().to_string();
                         let attribute = metric.attribute().to_string();
 
+                        let value_scaled = if let Some(decimal_places) = self.decimal_places {
+                            let scale = 10.0_f64.powi(decimal_places.get() as i32);
+                            (value.value * scale).round() / scale
+                        } else {
+                            value.value
+                        };
+
                         let record = CsvLongFmtRecord {
                             time_start: value.start,
                             time_end: value.end(),
                             scenario_index: scenario_idx,
                             metric_set: metric_set.name().to_string(),
                             name,
                             attribute,
-                            value: value.value,
+                            value: value_scaled,
                         };
 
                         internal

pywr-core/src/recorders/mod.rs

@@ -362,7 +362,7 @@ mod tests {
 
         let _idx = model.network_mut().add_recorder(Box::new(rec)).unwrap();
         // Test all solvers
-        run_all_solvers(&model, &[]);
+        run_all_solvers(&model, &[], &[]);
 
         // TODO fix this with respect to the trait.
         // let array = rec.data_view2().unwrap();

pywr-core/src/test_utils.rs

@@ -23,6 +23,7 @@ use float_cmp::{approx_eq, F64Margin};
 use ndarray::{Array, Array2};
 use rand::Rng;
 use rand_distr::{Distribution, Normal};
+use std::path::PathBuf;
 
 pub fn default_timestepper() -> Timestepper {
     let start = NaiveDate::from_ymd_opt(2020, 1, 1)
@@ -163,21 +164,42 @@ pub fn run_and_assert_parameter(
     let rec = AssertionRecorder::new("assert", p_idx.into(), expected_values, ulps, epsilon);
 
     model.network_mut().add_recorder(Box::new(rec)).unwrap();
-    run_all_solvers(model, &[])
+    run_all_solvers(model, &[], &[])
+}
+
+/// A struct to hold the expected outputs for a test.
+pub struct ExpectedOutputs {
+    actual_path: PathBuf,
+    expected_str: &'static str,
+}
+
+impl ExpectedOutputs {
+    pub fn new(actual_path: PathBuf, expected_str: &'static str) -> Self {
+        Self {
+            actual_path,
+            expected_str,
+        }
+    }
+
+    fn verify(&self) {
+        assert!(self.actual_path.exists());
+        let actual_str = std::fs::read_to_string(&self.actual_path).unwrap();
+        assert_eq!(actual_str, self.expected_str);
+    }
 }
 
 /// Run a model using each of the in-built solvers.
 ///
 /// The model will only be run if the solver has the required solver features (and
 /// is also enabled as a Cargo feature).
-pub fn run_all_solvers(model: &Model, solvers_without_features: &[&str]) {
-    check_features_and_run::<ClpSolver>(model, !solvers_without_features.contains(&"clp"));
+pub fn run_all_solvers(model: &Model, solvers_without_features: &[&str], expected_outputs: &[ExpectedOutputs]) {
+    check_features_and_run::<ClpSolver>(model, !solvers_without_features.contains(&"clp"), expected_outputs);
 
     #[cfg(feature = "cbc")]
-    check_features_and_run::<CbcSolver>(model, !solvers_without_features.contains(&"cbc"));
+    check_features_and_run::<CbcSolver>(model, !solvers_without_features.contains(&"cbc"), expected_outputs);
 
     #[cfg(feature = "highs")]
-    check_features_and_run::<HighsSolver>(model, !solvers_without_features.contains(&"highs"));
+    check_features_and_run::<HighsSolver>(model, !solvers_without_features.contains(&"highs"), expected_outputs);
 
     #[cfg(feature = "ipm-simd")]
     {
@@ -199,7 +221,7 @@ pub fn run_all_solvers(model: &Model, solvers_without_features: &[&str]) {
 }
 
 /// Check features and
-fn check_features_and_run<S>(model: &Model, expect_features: bool)
+fn check_features_and_run<S>(model: &Model, expect_features: bool, expected_outputs: &[ExpectedOutputs])
 where
     S: Solver,
     <S as Solver>::Settings: SolverSettings + Default,
@@ -214,6 +236,11 @@ where
         model
             .run::<S>(&Default::default())
             .unwrap_or_else(|_| panic!("Failed to solve with: {}", S::name()));
+
+        // Verify any expected outputs
+        for expected_output in expected_outputs {
+            expected_output.verify();
+        }
     } else {
         assert!(
             !has_features,

pywr-core/src/virtual_storage.rs

@@ -422,7 +422,7 @@ mod tests {
         let domain = default_timestepper().try_into().unwrap();
         let model = Model::new(domain, network);
         // Test all solvers
-        run_all_solvers(&model, &["highs"]);
+        run_all_solvers(&model, &["highs"], &[]);
     }
 
     #[test]
@@ -449,7 +449,7 @@ mod tests {
         network.add_recorder(Box::new(recorder)).unwrap();
 
         // Test all solvers
-        run_all_solvers(&model, &["highs"]);
+        run_all_solvers(&model, &["highs"], &[]);
     }
 
     #[test]
@@ -489,6 +489,6 @@ mod tests {
         network.add_recorder(Box::new(recorder)).unwrap();
 
         // Test all solvers
-        run_all_solvers(&model, &["highs"]);
+        run_all_solvers(&model, &["highs"], &[]);
     }
 }

pywr-schema/src/model.rs

@@ -1066,7 +1066,7 @@ mod core_tests {
         network.add_recorder(Box::new(rec)).unwrap();
 
         // Test all solvers
-        run_all_solvers(&model, &[]);
+        run_all_solvers(&model, &[], &[]);
     }
 
     /// Test that a cycle in parameter dependencies does not load.

pywr-schema/src/nodes/core.rs

@@ -982,6 +982,6 @@ mod tests {
         let schema = PywrModel::from_str(data).unwrap();
         let model: pywr_core::models::Model = schema.build_model(None, None).unwrap();
         // Test all solvers
-        run_all_solvers(&model, &[]);
+        run_all_solvers(&model, &[], &[]);
     }
 }

pywr-schema/src/nodes/delay.rs

@@ -197,6 +197,6 @@ mod tests {
         network.add_recorder(Box::new(recorder)).unwrap();
 
         // Test all solvers
-        run_all_solvers(&model, &[]);
+        run_all_solvers(&model, &[], &[]);
     }
 }