test(runtime): add unit tests for borsh buffer and deserialization

Author: markovejnovic

hsrs/src/borsh_buffer.rs

@@ -35,3 +35,42 @@ fn hsrs_borsh_ptr(buf: &BorshBuffer) -> *const u8 {
 fn hsrs_borsh_free(buf: repr_c::Box<BorshBuffer>) {
     drop(buf);
 }
+
+#[cfg(test)]
+#[allow(
+    clippy::all,
+    clippy::pedantic,
+    clippy::nursery,
+    clippy::cargo,
+    clippy::unwrap_used,
+    clippy::expect_used,
+    clippy::missing_docs_in_private_items,
+    clippy::exhaustive_enums,
+    clippy::exhaustive_structs,
+    clippy::indexing_slicing,
+    clippy::shadow_reuse,
+    clippy::shadow_same,
+    clippy::shadow_unrelated
+)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn from_borsh_serializes_value() {
+        let buf = BorshBuffer::from_borsh(&42u32);
+        assert!(!buf.bytes.is_empty());
+    }
+
+    #[test]
+    fn borsh_len_returns_byte_count() {
+        let buf = BorshBuffer::from_borsh(&42u32);
+        assert_eq!(hsrs_borsh_len(&buf), buf.bytes.len() as u64);
+    }
+
+    #[test]
+    fn borsh_ptr_returns_valid_pointer() {
+        let buf = BorshBuffer::from_borsh(&42u32);
+        let ptr = hsrs_borsh_ptr(&buf);
+        assert_eq!(ptr, buf.bytes.as_ptr());
+    }
+}

hsrs/src/ffi_utils.rs

@@ -11,3 +11,32 @@ pub unsafe fn borsh_deserialize<T: borsh::BorshDeserialize>(ptr: *const u8, len:
     let bytes = unsafe { core::slice::from_raw_parts(ptr, len as usize) };
     borsh::from_slice(bytes).expect("hsrs: borsh deserialization failed")
 }
+
+#[cfg(test)]
+#[allow(
+    clippy::all,
+    clippy::pedantic,
+    clippy::nursery,
+    clippy::cargo,
+    clippy::unwrap_used,
+    clippy::expect_used,
+    unsafe_code,
+    clippy::missing_docs_in_private_items,
+    clippy::exhaustive_enums,
+    clippy::exhaustive_structs,
+    clippy::indexing_slicing,
+    clippy::shadow_reuse,
+    clippy::shadow_same,
+    clippy::shadow_unrelated
+)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn borsh_deserialize_roundtrips() {
+        let original: u32 = 42;
+        let bytes = borsh::to_vec(&original).unwrap();
+        let result: u32 = unsafe { borsh_deserialize(bytes.as_ptr(), bytes.len() as u64) };
+        assert_eq!(result, original);
+    }
+}