feat(bitgo): add example to sanitize unwitnessed txn from cardano cli

EA-658

examples/js/ada/sanitize-unwitnessed-pledge-txn.js

@@ -0,0 +1,33 @@
+// There are known serialization inconsistencies between the cardano-cli and nodejs libraries. As a workaround, ADA pledge txn
+// needs to be re-serialized using the nodejs library before witnessed by node key and then submitted to BitGo pledge endpoint.
+// This script helps to re-serialize the pledge txn using the nodejs library.
+const fs = require('fs');
+const BitGoJS = require('bitgo');
+const { Transaction } = require('@bitgo/sdk-coin-ada');
+const bitgo = new BitGoJS.BitGo({ env: 'test' });
+const coin = 'tada';
+const basecoin = bitgo.coin(coin);
+
+const unwitnessedTxCborHex = 'replaced by CBOR hex of unwitnessed tx from cardano-cli';
+
+const tx = new Transaction(basecoin);
+tx.fromRawTransaction(unwitnessedTxCborHex);
+const sanitizedUnwitnessedTxn = tx.toBroadcastFormat();
+
+const unwitnessedTxn = JSON.stringify(
+  {
+    type: 'Unwitnessed Tx BabbageEra',
+    description: 'Ledger Cddl Format',
+    cborHex: sanitizedUnwitnessedTxn,
+  },
+  null,
+  4
+);
+
+fs.writeFile('sanitized_unwitnessed_pledge_txn.tx', unwitnessedTxn, (err) => {
+  if (err) {
+    console.error('Error writing to sanitized txn.', err);
+  } else {
+    console.log('Successfully saved to sanitized txn.');
+  }
+});