Move Form and Species to traits, implement a bunch of mocks

src/static_data/natures.rs

@@ -80,3 +80,23 @@ impl ValueIdentifiable for NatureImpl {
         self.identifier
     }
 }
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use super::*;
+
+    mockall::mock! {
+        #[derive(Debug)]
+        pub Nature {}
+        impl Nature for Nature {
+            fn increased_stat(&self) -> Statistic;
+            fn decreased_stat(&self) -> Statistic;
+            fn get_stat_modifier(&self, stat: Statistic) -> f32;
+        }
+        impl ValueIdentifiable for Nature {
+            fn value_identifier(&self) -> ValueIdentifier {
+                ValueIdentifier::new(0)
+            }
+        }
+    }
+}