fix: query Nonce account

web3.js/src/nonce-account.js

@@ -0,0 +1,40 @@
+// @flow
+import * as BufferLayout from 'buffer-layout';
+
+import type {Blockhash} from './blockhash';
+import * as Layout from './layout';
+import {PublicKey} from './publickey';
+
+/**
+ * See https://github.com/solana-labs/solana/blob/0ea2843ec9cdc517572b8e62c959f41b55cf4453/sdk/src/nonce_state.rs#L29-L32
+ *
+ * @private
+ */
+const NonceAccountLayout = BufferLayout.struct([
+  BufferLayout.u32('state'),
+  Layout.publicKey('authorizedPubkey'),
+  Layout.publicKey('hash'),
+]);
+
+/**
+ * NonceAccount class
+ */
+export class NonceAccount {
+  authorizedPubkey: PublicKey;
+  nonce: Blockhash;
+
+  /**
+   * Deserialize NonceAccount from the account data.
+   *
+   * @param buffer account data
+   * @return NonceAccount
+   */
+  static fromAccountData(buffer: Buffer): NonceAccount {
+    const nonceAccount = NonceAccountLayout.decode(buffer, 0);
+    nonceAccount.authorizedPubkey = new PublicKey(
+      nonceAccount.authorizedPubkey,
+    );
+    nonceAccount.nonce = new PublicKey(nonceAccount.nonce).toString();
+    return nonceAccount;
+  }
+}