Remove use of unwrap() in hash_to_point test

zcash · Jun 5, 2021 · edc6ec4 · edc6ec4
1 parent 1e9fa9e
commit edc6ec4
Showing 1 changed file with 30 additions and 25 deletions.
diff --git a/src/circuit/gadget/sinsemilla/chip/hash_to_point.rs b/src/circuit/gadget/sinsemilla/chip/hash_to_point.rs
@@ -58,34 +58,39 @@ impl<C: CurveAffine, const K: usize, const MAX_WORDS: usize> SinsemillaChip<C, K
         #[allow(non_snake_case)]
         // Check equivalence to result from primitives::sinsemilla::hash_to_point
         {
-            use crate::primitives::sinsemilla::S_PERSONALIZATION;
             use crate::circuit::gadget::sinsemilla::message::MessagePiece;
+            use crate::primitives::sinsemilla::S_PERSONALIZATION;
             use halo2::arithmetic::CurveExt;
 
-            // Get message as a bitstring.
-            let bitstring: Vec<bool> = message
-                .0
-                .iter()
-                .map(|piece: &MessagePiece<C::Base, K>| {
-                    piece
-                        .field_elem()
-                        .unwrap()
-                        .to_le_bits()
-                        .into_iter()
-                        .take(K * piece.num_words())
-                        .collect::<Vec<_>>()
-                })
-                .flatten()
-                .collect();
-
-            let hasher_S = C::CurveExt::hash_to_curve(S_PERSONALIZATION);
-            let S = |chunk: &[bool]| hasher_S(&lebs2ip_k(chunk).to_le_bytes());
-
-            let expected_point = bitstring
-                .chunks(K)
-                .fold(Q.to_curve(), |acc, chunk| (acc + S(chunk)) + acc);
-            let actual_point = C::from_xy(x_a.value().unwrap(), y_a.unwrap()).unwrap();
-            assert_eq!(expected_point.to_affine(), actual_point);
+            let field_elems: Option<Vec<C::Base>> =
+                message.0.iter().map(|piece| piece.field_elem()).collect();
+
+            if let Some(_) = field_elems {
+                // Get message as a bitstring.
+                let bitstring: Vec<bool> = message
+                    .0
+                    .iter()
+                    .map(|piece: &MessagePiece<C::Base, K>| {
+                        piece
+                            .field_elem()
+                            .unwrap()
+                            .to_le_bits()
+                            .into_iter()
+                            .take(K * piece.num_words())
+                            .collect::<Vec<_>>()
+                    })
+                    .flatten()
+                    .collect();
+
+                let hasher_S = C::CurveExt::hash_to_curve(S_PERSONALIZATION);
+                let S = |chunk: &[bool]| hasher_S(&lebs2ip_k(chunk).to_le_bytes());
+
+                let expected_point = bitstring
+                    .chunks(K)
+                    .fold(Q.to_curve(), |acc, chunk| (acc + S(chunk)) + acc);
+                let actual_point = C::from_xy(x_a.value().unwrap(), y_a.unwrap()).unwrap();
+                assert_eq!(expected_point.to_affine(), actual_point);
+            }
         }
 
         // Enable `Sinsemilla` selector on the last double-and-add row for expr1