fix: always include amount in transaction payloads (#202)

Author: sleepdefic1t

src/include/cpp-crypto/interfaces/constants.h

@@ -76,6 +76,9 @@ constexpr size_t WIF_STRING_LEN         = 52U;
 constexpr auto KEY_ASSET_LABEL  = "asset";
 const auto KEY_ASSET_SIZE       = strlen(KEY_ASSET_LABEL);
 
+constexpr auto KEY_AMOUNT_LABEL = "amount";
+const auto KEY_AMOUNT_SIZE      = strlen(KEY_AMOUNT_LABEL);
+
 ////////////////////////////////////////////////////////////////////////////////
 // Misc
 constexpr uint8_t BASE_10 = 10U;

src/transactions/mapping/json.cpp

@@ -74,6 +74,12 @@ static auto getCommonJsonCapacity(
                             KEY_TIMESTAMP_SIZE + UINT32_MAX_CHARS;
     }
 
+    // Amount
+    if (transactionVersion == TRANSACTION_VERSION_TYPE_2) {
+        commonCapacity += JSON_OBJECT_SIZE(1) +
+                            KEY_AMOUNT_SIZE + UINT64_MAX_CHARS;
+    }
+
     // Vendorfield
     if (map.find(KEY_VENDORFIELD_LABEL) != map.end()) {
         commonCapacity += JSON_OBJECT_SIZE(1) +
@@ -244,6 +250,12 @@ static void mapCommonJson(DynamicJsonDocument &jsonDoc,
     // Fee
     jsonDoc[KEY_FEE_LABEL] = map.at(KEY_FEE_LABEL);
 
+    // Amount
+    jsonDoc[KEY_AMOUNT_LABEL] = map.find(KEY_AMOUNT_LABEL) == map.end() &&
+                                transactionVersion == TRANSACTION_VERSION_TYPE_2
+                                        ? "0"
+                                        : map.at(KEY_AMOUNT_LABEL);
+
     // VendorField
     if (map.find(KEY_VENDORFIELD_LABEL) != map.end()) {
         jsonDoc[KEY_VENDORFIELD_LABEL] = map.at(KEY_VENDORFIELD_LABEL);

src/transactions/types/multi_payment.cpp

@@ -175,9 +175,6 @@ const auto KEY_AMOUNTS_SIZE         = strlen(KEY_AMOUNTS_LABEL);
 constexpr auto KEY_ADDRESSES_LABEL  = "addresses";
 const auto KEY_ADDRESSES_SIZE       = strlen(KEY_ADDRESSES_LABEL);
 
-constexpr auto KEY_AMOUNT_LABEL     = "amount";
-const auto KEY_AMOUNT_SIZE          = strlen(KEY_AMOUNT_LABEL);
-
 constexpr auto KEY_RECIPIENT_ID_LABEL   = "recipientId";
 const auto KEY_RECIPIENT_ID_SIZE        = strlen(KEY_RECIPIENT_ID_LABEL);