feat: add getMultipleAccountsInfo which uses the getMultipleAccounts RPC method (#18736)

* feat(web3): add getMultipleAccountsInfo which uses the getMultipleAccounts RPC method

* fix: add airdrop to get multiple accounts info

Co-authored-by: Josh Hundley <josh.hundley@gmail.com>

web3.js/src/connection.ts

@@ -2407,6 +2407,28 @@ export class Connection {
     }
   }
 
+  /**
+   * Fetch all the account info for multiple accounts specified by an array of public keys
+   */
+  async getMultipleAccountsInfo(
+    publicKeys: PublicKey[],
+    commitment?: Commitment,
+  ): Promise<AccountInfo<Buffer>[] | null> {
+    const keys = publicKeys.map(key => key.toBase58());
+    const args = this._buildArgs([keys], commitment, 'base64');
+    const unsafeRes = await this._rpcRequest('getMultipleAccounts', args);
+    const res = create(
+      unsafeRes,
+      jsonRpcResultAndContext(nullable(array(AccountInfoResult))),
+    );
+    if ('error' in res) {
+      throw new Error(
+        'failed to get info for accounts ' + keys + ': ' + res.error.message,
+      );
+    }
+    return res.result.value;
+  }
+
   /**
    * Returns epoch activation information for a stake account that has been delegated
    */

web3.js/test/connection.test.ts

@@ -155,6 +155,76 @@ describe('Connection', () => {
       .be.null;
   });
 
+  it('get multiple accounts info', async () => {
+    const account1 = Keypair.generate();
+    const account2 = Keypair.generate();
+
+    {
+      await helpers.airdrop({
+        connection,
+        address: account1.publicKey,
+        amount: LAMPORTS_PER_SOL,
+      });
+
+      await helpers.airdrop({
+        connection,
+        address: account2.publicKey,
+        amount: LAMPORTS_PER_SOL,
+      });
+    }
+
+    const value = [
+      {
+        owner: '11111111111111111111111111111111',
+        lamports: LAMPORTS_PER_SOL,
+        data: ['', 'base64'],
+        executable: false,
+        rentEpoch: 0,
+      },
+      {
+        owner: '11111111111111111111111111111111',
+        lamports: LAMPORTS_PER_SOL,
+        data: ['', 'base64'],
+        executable: false,
+        rentEpoch: 0,
+      },
+    ];
+
+    await mockRpcResponse({
+      method: 'getMultipleAccounts',
+      params: [
+        [account1.publicKey.toBase58(), account2.publicKey.toBase58()],
+        {encoding: 'base64'},
+      ],
+      value: value,
+      withContext: true,
+    });
+
+    const res = await connection.getMultipleAccountsInfo(
+      [account1.publicKey, account2.publicKey],
+      'confirmed',
+    );
+
+    const expectedValue = [
+      {
+        owner: new PublicKey('11111111111111111111111111111111'),
+        lamports: LAMPORTS_PER_SOL,
+        data: Buffer.from([]),
+        executable: false,
+        rentEpoch: 0,
+      },
+      {
+        owner: new PublicKey('11111111111111111111111111111111'),
+        lamports: LAMPORTS_PER_SOL,
+        data: Buffer.from([]),
+        executable: false,
+        rentEpoch: 0,
+      },
+    ];
+
+    expect(res).to.eql(expectedValue);
+  });
+
   it('get program accounts', async () => {
     const account0 = Keypair.generate();
     const account1 = Keypair.generate();