token-js: expose unpack methods (#3471)

* feat: expose unpack methods

* default program id

Co-authored-by: Arrowana <[email protected]>

Author: Arrowana

token/js/src/state/account.ts

@@ -157,7 +157,18 @@ export async function getMinimumBalanceForRentExemptAccountWithExtensions(
     return await connection.getMinimumBalanceForRentExemption(accountLen, commitment);
 }
 
-function unpackAccount(info: AccountInfo<Buffer> | null, address: PublicKey, programId: PublicKey) {
+/**
+ * Unpacks a token account
+ * @param info the token account on-chain account
+ * @param address TokenAccount
+ * @param programId SPL Token program account
+ * @returns
+ */
+export function unpackAccount(
+    info: AccountInfo<Buffer> | null,
+    address: PublicKey,
+    programId: PublicKey = TOKEN_PROGRAM_ID
+): Account {
     if (!info) throw new TokenAccountNotFoundError();
     if (!info.owner.equals(programId)) throw new TokenInvalidAccountOwnerError();
     if (info.data.length < ACCOUNT_SIZE) throw new TokenInvalidAccountSizeError();

token/js/src/state/mint.ts

@@ -1,6 +1,6 @@
 import { struct, u32, u8 } from '@solana/buffer-layout';
 import { bool, publicKey, u64 } from '@solana/buffer-layout-utils';
-import { Commitment, Connection, PublicKey } from '@solana/web3.js';
+import { AccountInfo, Commitment, Connection, PublicKey } from '@solana/web3.js';
 import { ASSOCIATED_TOKEN_PROGRAM_ID, TOKEN_PROGRAM_ID } from '../constants';
 import {
     TokenAccountNotFoundError,
@@ -77,6 +77,21 @@ export async function getMint(
     programId = TOKEN_PROGRAM_ID
 ): Promise<Mint> {
     const info = await connection.getAccountInfo(address, commitment);
+    return unpackMint(info, address, programId);
+}
+
+/**
+ * Unpacks a mint
+ * @param info the mint on-chain account
+ * @param address Mint
+ * @param programId SPL Token program account
+ * @returns
+ */
+export function unpackMint(
+    info: AccountInfo<Buffer> | null,
+    address: PublicKey,
+    programId: PublicKey = TOKEN_PROGRAM_ID
+): Mint {
     if (!info) throw new TokenAccountNotFoundError();
     if (!info.owner.equals(programId)) throw new TokenInvalidAccountOwnerError();
     if (info.data.length < MINT_SIZE) throw new TokenInvalidAccountSizeError();