Unit tests for key encodings

Closes #119.

zcash_client_backend/src/encoding.rs

@@ -183,11 +183,95 @@ mod tests {
     use zcash_primitives::{
         jubjub::edwards,
         primitives::{Diversifier, PaymentAddress},
+        zip32::ExtendedSpendingKey,
     };
 
-    use super::{decode_payment_address, encode_payment_address};
+    use super::{
+        decode_extended_full_viewing_key, decode_extended_spending_key, decode_payment_address,
+        encode_extended_full_viewing_key, encode_extended_spending_key, encode_payment_address,
+    };
     use crate::constants;
 
+    #[test]
+    fn extended_spending_key() {
+        let extsk = ExtendedSpendingKey::master(&[0; 32][..]);
+
+        let encoded_main = "secret-extended-key-main1qqqqqqqqqqqqqq8n3zjjmvhhr854uy3qhpda3ml34haf0x388z5r7h4st4kpsf6qysqws3xh6qmha7gna72fs2n4clnc9zgyd22s658f65pex4exe56qjk5pqj9vfdq7dfdhjc2rs9jdwq0zl99uwycyrxzp86705rk687spn44e2uhm7h0hsagfvkk4n7n6nfer6u57v9cac84t7nl2zth0xpyfeg0w2p2wv2yn6jn923aaz0vdaml07l60ahapk6efchyxwysrvjs87qvlj";
+        let encoded_test = "secret-extended-key-test1qqqqqqqqqqqqqq8n3zjjmvhhr854uy3qhpda3ml34haf0x388z5r7h4st4kpsf6qysqws3xh6qmha7gna72fs2n4clnc9zgyd22s658f65pex4exe56qjk5pqj9vfdq7dfdhjc2rs9jdwq0zl99uwycyrxzp86705rk687spn44e2uhm7h0hsagfvkk4n7n6nfer6u57v9cac84t7nl2zth0xpyfeg0w2p2wv2yn6jn923aaz0vdaml07l60ahapk6efchyxwysrvjsvzyw8j";
+
+        assert_eq!(
+            encode_extended_spending_key(
+                constants::mainnet::HRP_SAPLING_EXTENDED_SPENDING_KEY,
+                &extsk
+            ),
+            encoded_main
+        );
+        assert_eq!(
+            decode_extended_spending_key(
+                constants::mainnet::HRP_SAPLING_EXTENDED_SPENDING_KEY,
+                encoded_main
+            )
+            .unwrap(),
+            Some(extsk.clone())
+        );
+
+        assert_eq!(
+            encode_extended_spending_key(
+                constants::testnet::HRP_SAPLING_EXTENDED_SPENDING_KEY,
+                &extsk
+            ),
+            encoded_test
+        );
+        assert_eq!(
+            decode_extended_spending_key(
+                constants::testnet::HRP_SAPLING_EXTENDED_SPENDING_KEY,
+                encoded_test
+            )
+            .unwrap(),
+            Some(extsk)
+        );
+    }
+
+    #[test]
+    fn extended_full_viewing_key() {
+        let extfvk = (&ExtendedSpendingKey::master(&[0; 32][..])).into();
+
+        let encoded_main = "zxviews1qqqqqqqqqqqqqq8n3zjjmvhhr854uy3qhpda3ml34haf0x388z5r7h4st4kpsf6qy3zw4wc246aw9rlfyg5ndlwvne7mwdq0qe6vxl42pqmcf8pvmmd5slmjxduqa9evgej6wa3th2505xq4nggrxdm93rxk4rpdjt5nmq2vn44e2uhm7h0hsagfvkk4n7n6nfer6u57v9cac84t7nl2zth0xpyfeg0w2p2wv2yn6jn923aaz0vdaml07l60ahapk6efchyxwysrvjsxmansf";
+        let encoded_test = "zxviewtestsapling1qqqqqqqqqqqqqq8n3zjjmvhhr854uy3qhpda3ml34haf0x388z5r7h4st4kpsf6qy3zw4wc246aw9rlfyg5ndlwvne7mwdq0qe6vxl42pqmcf8pvmmd5slmjxduqa9evgej6wa3th2505xq4nggrxdm93rxk4rpdjt5nmq2vn44e2uhm7h0hsagfvkk4n7n6nfer6u57v9cac84t7nl2zth0xpyfeg0w2p2wv2yn6jn923aaz0vdaml07l60ahapk6efchyxwysrvjs8evfkz";
+
+        assert_eq!(
+            encode_extended_full_viewing_key(
+                constants::mainnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY,
+                &extfvk
+            ),
+            encoded_main
+        );
+        assert_eq!(
+            decode_extended_full_viewing_key(
+                constants::mainnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY,
+                encoded_main
+            )
+            .unwrap(),
+            Some(extfvk.clone())
+        );
+
+        assert_eq!(
+            encode_extended_full_viewing_key(
+                constants::testnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY,
+                &extfvk
+            ),
+            encoded_test
+        );
+        assert_eq!(
+            decode_extended_full_viewing_key(
+                constants::testnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY,
+                encoded_test
+            )
+            .unwrap(),
+            Some(extfvk)
+        );
+    }
+
     #[test]
     fn payment_address() {
         let rng = &mut XorShiftRng::from_seed([