fix: added error with clear message when signing a tx without outputs

Author: gomezdn

src/transaction.js

@@ -318,6 +318,8 @@ class Transaction {
       hashSequences = bcrypto.sha256(bufferWriter.end());
     }
     if (!(isNone || isSingle)) {
+      if (!this.outs.length)
+        throw new Error('Add outputs to the transaction before signing.');
       const txOutsSize = this.outs
         .map(output => 8 + varSliceSize(output.script))
         .reduce((a, b) => a + b);

ts_src/transaction.ts

@@ -414,6 +414,8 @@ export class Transaction {
     }
 
     if (!(isNone || isSingle)) {
+      if (!this.outs.length)
+        throw new Error('Add outputs to the transaction before signing.');
       const txOutsSize = this.outs
         .map(output => 8 + varSliceSize(output.script))
         .reduce((a, b) => a + b);