add tests

Author: jialinli98

src/scalar_field.nr

@@ -165,6 +165,11 @@ impl<let N: u32> std::convert::Into<Field> for ScalarField<N> {
      **/
     fn into(self: Self) -> Field {
         // TODO: This is susceptible to overflow when N is large!
+        if !std::runtime::is_unconstrained() {
+            if N >= 64 {
+                compare_scalar_field_to_bignum(self);
+            }
+        }
         let mut acc: Field = 0;
         for i in 0..N {
             acc = acc * 16;
@@ -372,4 +377,48 @@ mod tests {
                 ],
         );
     }
+    #[test(should_fail)]
+    fn test_get_modulus_slices_fail_64() {
+        //13th nibble is 14, which is greater than the modulus
+        let modulus_slices: [u8; 64] = [
+            9, 8, 3, 2, 2, 7, 3, 9, 7, 0, 9, 8, 14, 0, 1, 4, 13, 12, 2, 8, 2, 2, 13, 11, 4, 0, 12,
+            0, 10, 12, 2, 14, 9, 4, 1, 9, 15, 4, 2, 4, 3, 12, 13, 12, 11, 8, 4, 8, 10, 1, 15, 0, 15,
+            10, 12, 9, 15, 8, 0, 0, 0, 0, 0, 0,
+        ];
+        let mut result: ScalarField<64> = ScalarField { base4_slices: [0; 64], skew: true };
+        for i in 0..64 {
+            result.base4_slices[i] = modulus_slices[i];
+        }
+        let _ = result.into();
+    }
+    #[test(should_fail)]
+    fn test_get_modulus_slices_fail_65() {
+        //modulus slice represents a number that is greater than the modulus
+        let modulus_slices2 = [
+            8, 1, 8, 3, 2, 2, 7, 3, 10, 8, 0, 9, 8, 13, 0, 1, 4, 13, 12, 2, 8, 2, 2, 13, 11, 4, 0,
+            12, 0, 10, 12, 2, 14, 9, 4, 1, 9, 15, 4, 2, 4, 3, 12, 13, 12, 11, 8, 4, 8, 10, 1, 15, 0,
+            15, 10, 12, 9, 15, 8, 0, 0, 0, 0, 0, 0,
+        ];
+        let mut result: ScalarField<65> = ScalarField { base4_slices: [0; 65], skew: true };
+        for i in 0..64 {
+            result.base4_slices[i] = modulus_slices2[i];
+        }
+        let _ = result.into();
+    }
+
+    #[test(should_fail)]
+    fn test_get_modulus_slices_fail_68() {
+        //modulus slice represents a number that is greater than the modulus
+        let modulus_slices3 = [
+            8, 0, 0, 0, 2, 8, 3, 2, 2, 7, 3, 9, 7, 0, 9, 8, 13, 0, 1, 4, 13, 12, 2, 8, 2, 2, 13, 11,
+            4, 0, 12, 0, 10, 12, 2, 14, 9, 4, 1, 9, 15, 4, 2, 4, 3, 12, 13, 12, 11, 8, 4, 8, 10, 1,
+            15, 0, 15, 10, 12, 9, 15, 8, 0, 0, 0, 0, 0, 0,
+        ];
+        let mut result: ScalarField<68> = ScalarField { base4_slices: [0; 68], skew: true };
+        for i in 0..68 {
+            result.base4_slices[i] = modulus_slices3[i];
+        }
+        let _ = result.into();
+    }
+
 }