Add test for GetNoteDecryptor()

src/gtest/test_keystore.cpp

@@ -27,3 +27,15 @@ TEST(keystore_tests, store_and_retrieve_spending_key) {
     EXPECT_EQ(1, addrs.size());
     EXPECT_EQ(1, addrs.count(addr));
 }
+
+TEST(keystore_tests, store_and_retrieve_note_decryptor) {
+    CBasicKeyStore keyStore;
+    ZCNoteDecryption decOut;
+
+    auto sk = libzcash::SpendingKey::random();
+    auto addr = sk.address();
+    keyStore.AddSpendingKey(sk);
+
+    keyStore.GetNoteDecryptor(addr, decOut);
+    EXPECT_EQ(ZCNoteDecryption(sk.viewing_key()), decOut);
+}

src/zcash/NoteEncryption.hpp

@@ -71,6 +71,7 @@ public:
                       unsigned char nonce
                      ) const;
 
+    friend inline bool operator==(const NoteDecryption& a, const NoteDecryption& b) { return a.sk_enc == b.sk_enc && a.pk_enc == b.pk_enc; }
     friend inline bool operator<(const NoteDecryption& a, const NoteDecryption& b) { return a.pk_enc < b.pk_enc; }
 };