fix: addpair should prevent adding same base and quote assets (#1559)

Author: rsercano

Diff for: lib/grpc/getGrpcError.ts

@@ -22,6 +22,7 @@ const getGrpcError = (err: any) => {
     case orderErrorCodes.MIN_QUANTITY_VIOLATED:
     case orderErrorCodes.QUANTITY_DOES_NOT_MATCH:
     case swapErrorCodes.REMOTE_IDENTIFIER_MISSING:
+    case orderErrorCodes.DUPLICATE_PAIR_CURRENCIES:
       code = status.INVALID_ARGUMENT;
       break;
     case orderErrorCodes.PAIR_DOES_NOT_EXIST:

Diff for: lib/orderbook/OrderBook.ts

@@ -290,6 +290,9 @@ class OrderBook extends EventEmitter {
 
   public addPair = async (pair: Pair) => {
     const pairId = derivePairId(pair);
+    if (pair.baseCurrency.toLowerCase() === pair.quoteCurrency.toLowerCase()) {
+      throw errors.DUPLICATE_PAIR_CURRENCIES(pair.baseCurrency, pair.quoteCurrency);
+    }
     if (this.pairInstances.has(pairId)) {
       throw errors.PAIR_ALREADY_EXISTS(pairId);
     }

Diff for: lib/orderbook/errors.ts

@@ -16,6 +16,7 @@ const errorCodes = {
   INSUFFICIENT_OUTBOUND_BALANCE: codesPrefix.concat('.12'),
   MIN_QUANTITY_VIOLATED: codesPrefix.concat('.13'),
   QUANTITY_ON_HOLD: codesPrefix.concat('.15'),
+  DUPLICATE_PAIR_CURRENCIES: codesPrefix.concat('.16'),
 };
 
 const errors = {
@@ -75,6 +76,10 @@ const errors = {
     message: `order with local id ${localId} has a quantity of ${holdQuantity} satoshis on hold, try again later`,
     code: errorCodes.QUANTITY_DOES_NOT_MATCH,
   }),
+  DUPLICATE_PAIR_CURRENCIES: (baseCurrency: string, quoteCurrency: string) => ({
+    message: `base asset (${baseCurrency}) and quote asset (${quoteCurrency}) have to be different`,
+    code: errorCodes.DUPLICATE_PAIR_CURRENCIES,
+  }),
 };
 
 export { errorCodes };