ensure IndPtr is deserialized correctly

Author: mulimoen

sprs-tests/tests/tests.rs

@@ -59,4 +59,29 @@ mod serde_tests {
             serde_json::from_str(&json_mat);
         assert!(mat.is_err());
     }
+
+    #[test]
+    fn valid_indptr() {
+        let indptr = r#"{ "storage": [0, 0, 1, 2, 2, 6] }"#;
+        let indptr: IndPtr<usize> = serde_json::from_str(&indptr).unwrap();
+        assert_eq!(indptr.raw_storage(), &[0, 0, 1, 2, 2, 6]);
+
+        let indptr = r#"{ "storage": [5, 5, 8, 9] }"#;
+        let indptr: IndPtr<usize> = serde_json::from_str(&indptr).unwrap();
+        assert_eq!(indptr.raw_storage(), &[5, 5, 8, 9]);
+    }
+
+    #[test]
+    fn invalid_indptr() {
+        let indptr = r#"{ "storage": [0, 0, 1, 2, 2, 1] }"#;
+        let indptr: Result<IndPtr<usize>, _> = serde_json::from_str(&indptr);
+        assert!(indptr.is_err());
+        let indptr = r#"{ "storage": [2, 1, 2, 2, 2, 7] }"#;
+        let indptr: Result<IndPtr<usize>, _> = serde_json::from_str(&indptr);
+        assert!(indptr.is_err());
+        // Larger than permitted by i16
+        let indptr = r#"{ "storage": [0, 32768] }"#;
+        let indptr: Result<IndPtr<i16>, _> = serde_json::from_str(&indptr);
+        assert!(indptr.is_err());
+    }
 }

src/sparse/indptr.rs

@@ -3,6 +3,8 @@
 //!
 //! [`CsMatBase`]: type.CsMatBase.html
 
+#[cfg(feature = "serde")]
+use super::serde_traits::IndPtrBaseShadow;
 use crate::errors::SprsError;
 use crate::indexing::SpIndex;
 #[cfg(feature = "serde")]
@@ -12,6 +14,10 @@ use std::ops::{Deref, DerefMut};
 
 #[derive(Eq, PartialEq, Debug, Copy, Clone, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(
+    feature = "serde",
+    serde(try_from = "IndPtrBaseShadow<Iptr, Storage>")
+)]
 pub struct IndPtrBase<Iptr, Storage>
 where
     Iptr: SpIndex,

src/sparse/serde_traits.rs

@@ -71,3 +71,26 @@ where
             .map_err(|(_, _, _, e)| e)
     }
 }
+
+#[derive(Deserialize)]
+pub struct IndPtrBaseShadow<Iptr, Storage>
+where
+    Iptr: SpIndex,
+    Storage: Deref<Target = [Iptr]>,
+{
+    storage: Storage,
+}
+
+impl<Iptr: SpIndex, Storage> TryFrom<IndPtrBaseShadow<Iptr, Storage>>
+    for IndPtrBase<Iptr, Storage>
+where
+    Storage: Deref<Target = [Iptr]>,
+{
+    type Error = SprsError;
+    fn try_from(
+        val: IndPtrBaseShadow<Iptr, Storage>,
+    ) -> Result<Self, Self::Error> {
+        let IndPtrBaseShadow { storage } = val;
+        Self::new(storage)
+    }
+}