[Transfer] Fix known properties that don't meet SEP-24 spec (#130)

Some anchors don't 100% meet the SEP-24 spec for transaction object requirements, so normalize transaction responses to fix some known examples.

- Settle submits _id instead of id, so rewrite that if found.
- Saldo submits amount instead of amount_in and amount_out, so rewrite that if found.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@stellar/wallet-sdk",
-  "version": "0.0.8-rc.1",
+  "version": "0.0.8-rc.2",
   "description": "Libraries to help you write Stellar-enabled wallets in Javascript",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

src/transfers/TransferProvider.ts

@@ -43,6 +43,24 @@ interface TransactionsRegistry {
   [asset_code: string]: TransactionsRegistryAsset;
 }
 
+function _normalizeTransaction(transaction: Transaction) {
+  // some anchors (Settle) return _id instead of id, so rewrite that
+  if (transaction._id && transaction.id === undefined) {
+    transaction.id = transaction._id;
+  }
+
+  // others (Saldo) provide amount but not amount_in / amount_out
+  if (
+    transaction.amount &&
+    transaction.amount_in === undefined &&
+    transaction.amount_out === undefined
+  ) {
+    transaction.amount_in = transaction.amount;
+    transaction.amount_out = transaction.amount;
+  }
+  return transaction;
+}
+
 /**
  * TransferProvider is the base class for WithdrawProvider and DepositProvider.
  */
@@ -156,7 +174,7 @@ export abstract class TransferProvider {
 
     const { transactions } = await response.json();
 
-    return transactions;
+    return transactions.map(_normalizeTransaction);
   }
 
   /**
@@ -181,7 +199,7 @@ export abstract class TransferProvider {
 
     const transaction: Transaction = await response.json();
 
-    return transaction;
+    return _normalizeTransaction(transaction);
   }
 
   /**

src/types/transfers.ts

@@ -261,6 +261,10 @@ interface BaseTransaction {
   external_transaction_id?: string;
   message?: string;
   refunded?: boolean;
+
+  // these are off-spec props from certain anchors
+  _id?: string;
+  amount?: string;
 }
 
 export interface DepositTransaction extends BaseTransaction {