Improved error tests

src/error.rs

@@ -1,6 +1,6 @@
 use std::ffi::NulError;
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 pub enum Error {
     Io,
     Parameter(String),

src/model.rs

@@ -2,6 +2,7 @@ use crate::bindings::*;
 use crate::{Error, Matrix, Params};
 use std::ffi::CString;
 
+#[derive(Debug)]
 pub struct Model {
     pub(crate) model: *mut MfModel,
 }
@@ -102,7 +103,7 @@ impl Drop for Model {
 
 #[cfg(test)]
 mod tests {
-    use crate::{Loss, Matrix, Model};
+    use crate::{Error, Loss, Matrix, Model};
 
     fn generate_data() -> Matrix {
         let mut data = Matrix::new();
@@ -168,13 +169,13 @@ mod tests {
         let data = generate_data();
         let model = Model::params().quiet(true).fit(&data).unwrap();
         let result = model.save("/tmp/missing/model.txt");
-        assert!(result.is_err());
+        assert_eq!(result.unwrap_err(), Error::Io);
     }
 
     #[test]
     fn test_load_missing() {
         let result = Model::load("/tmp/missing.txt");
-        assert!(result.is_err());
+        assert_eq!(result.unwrap_err(), Error::Io);
     }
 
     #[test]
@@ -220,20 +221,29 @@ mod tests {
     fn test_fit_bad_params() {
         let data = generate_data();
         let result = Model::params().factors(0).fit(&data);
-        assert!(result.is_err());
+        assert_eq!(
+            result.unwrap_err(),
+            Error::Parameter("number of factors must be greater than zero".to_string())
+        );
     }
 
     #[test]
     fn test_fit_eval_bad_params() {
         let data = generate_data();
         let result = Model::params().factors(0).fit_eval(&data, &data);
-        assert!(result.is_err());
+        assert_eq!(
+            result.unwrap_err(),
+            Error::Parameter("number of factors must be greater than zero".to_string())
+        );
     }
 
     #[test]
     fn test_cv_bad_params() {
         let data = generate_data();
         let result = Model::params().factors(0).cv(&data, 5);
-        assert!(result.is_err());
+        assert_eq!(
+            result.unwrap_err(),
+            Error::Parameter("number of factors must be greater than zero".to_string())
+        );
     }
 }