fix: return signature from transfer transactions

web3.js/module.flow.js

@@ -170,7 +170,7 @@ declare module '@solana/web3.js' {
       source: PublicKey,
       destination: PublicKey,
       amount: number | TokenAmount,
-    ): Promise<void>;
+    ): Promise<TransactionSignature>;
     approve(
       owner: Account,
       account: PublicKey,

web3.js/src/token-program.js

@@ -11,6 +11,7 @@ import {Account} from './account';
 import {PublicKey} from './publickey';
 import {SystemProgram} from './system-program';
 import {Transaction, TransactionInstruction} from './transaction';
+import type {TransactionSignature} from './transaction';
 import {sendAndConfirmTransaction} from './util/send-and-confirm-transaction';
 import type {Connection} from './connection';
 
@@ -373,8 +374,8 @@ export class Token {
     source: PublicKey,
     destination: PublicKey,
     amount: number | TokenAmount,
-  ): Promise<void> {
-    await sendAndConfirmTransaction(
+  ): Promise<?TransactionSignature> {
+    return await sendAndConfirmTransaction(
       this.connection,
       owner,
       new Transaction().add(

web3.js/test/token-program.test.js

@@ -477,7 +477,12 @@ test('transfer', async () => {
     mockGetSignatureStatus();
   }
 
-  await testToken.transfer(initialOwner, initialOwnerTokenAccount, dest, 123);
+  await testToken.transfer(
+    initialOwner,
+    initialOwnerTokenAccount,
+    dest,
+    123,
+  );
 
   {
     // mock Token.accountInfo()'s getAccountInfo