solana.js

import * as bip32 from 'bip32';
import * as BufferLayout from 'buffer-layout';
import _ from 'lodash';
import nacl from 'tweetnacl';
import { Service } from 'typedi';

import {
    Account, Connection, PublicKey, SystemProgram, SYSVAR_RENT_PUBKEY, Transaction,
    TransactionInstruction
} from '@solana/web3.js';

import { env } from '../../env';
import { SolanaAccountQuery } from '../controllers/requests/SolanaQuery';

@Service()
export class SolanaService {

    public async getTransactions(
        solanaAccountQuery: SolanaAccountQuery
    ): Promise<object> {
        const ACCOUNT_LAYOUT = BufferLayout.struct([
            BufferLayout.blob(32, 'mint'),
            BufferLayout.blob(32, 'owner'),
            BufferLayout.nu64('amount'),
            BufferLayout.blob(93),
        ]);

        const TOKEN_PROGRAM_ID = new PublicKey(
            'TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA'
        );

        const headers = {};
        const endpoint = env.solana.mainNetUrl;

        const params = { headers, method: 'POST' };
        const path = `coins/eth/${solanaAccountQuery.token}`;
        headers['Content-Type'] = 'application/json';
        const resp: any = await fetch(`https://swap.sollet.io/api/${path}`, params);
        let json = await resp.json();
        json = json.result;
        const mint = new PublicKey(json.splMint);

        const bip39 = await import('bip39');
        let seed: any = await bip39.mnemonicToSeed(solanaAccountQuery.mnemonic);
        seed = Buffer.from(seed, 'hex');

        const connection = new Connection(endpoint, 'recent');

        const derivedSeed = bip32
            .fromSeed(seed)
            .derivePath(`m/501'/0'/0/0`).privateKey;

        const account = new Account(nacl.sign.keyPair.fromSeed(derivedSeed).secretKey);
        const newAccount = new Account();

        const transaction = new Transaction();
        console.log(transaction) // when I console this I see empty signature array whereas when I console the tx object just after this line https://github.com/project-serum/spl-token-wallet/blob/master/src/utils/tokens/index.js#L128 I see signatures array populated I am using the latest solana web3 version
        transaction.add(
            SystemProgram.createAccount({
                fromPubkey: account.publicKey,
                newAccountPubkey: newAccount.publicKey,
                lamports: await connection.getMinimumBalanceForRentExemption(
                    ACCOUNT_LAYOUT.span
                ),
                space: ACCOUNT_LAYOUT.span,
                programId: TOKEN_PROGRAM_ID,
            })
        );
        transaction.add(
            await this.initializeAccount({
                account: newAccount.publicKey,
                mint,
                owner: account.publicKey,
            })
        );
        return transaction;
    }

    public async initializeAccount({ account, mint, owner }) {

        const TOKEN_PROGRAM_ID = new PublicKey(
            'TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA'
        );
        const keys = [
            { pubkey: account, isSigner: false, isWritable: true },
            { pubkey: mint, isSigner: false, isWritable: false },
            { pubkey: owner, isSigner: false, isWritable: false },
            { pubkey: SYSVAR_RENT_PUBKEY, isSigner: false, isWritable: false },
        ];
        return new TransactionInstruction({
            keys,
            data: await this.encodeTokenInstructionData({
                initializeAccount: {},
            }),
            programId: TOKEN_PROGRAM_ID,
        });
    }

    public async encodeTokenInstructionData(instruction: any) {
        const LAYOUT = BufferLayout.union(BufferLayout.u8('instruction'));
        LAYOUT.addVariant(
            0,
            BufferLayout.struct([
                BufferLayout.u8('decimals'),
                BufferLayout.blob(32, 'mintAuthority'),
                BufferLayout.u8('freezeAuthorityOption'),
                BufferLayout.blob(32, 'freezeAuthority'),
            ]),
            'initializeMint'
        );
        LAYOUT.addVariant(1, BufferLayout.struct([]), 'initializeAccount');
        LAYOUT.addVariant(
            3,
            BufferLayout.struct([BufferLayout.nu64('amount')]),
            'transfer'
        );
        LAYOUT.addVariant(
            7,
            BufferLayout.struct([BufferLayout.nu64('amount')]),
            'mintTo'
        );
        LAYOUT.addVariant(
            8,
            BufferLayout.struct([BufferLayout.nu64('amount')]),
            'burn'
        );
        LAYOUT.addVariant(9, BufferLayout.struct([]), 'closeAccount');

        const instructionMaxSpan = Math.max(
            ...Object.values(LAYOUT.registry).map((r: any) => r.span)
        );
        const b = Buffer.alloc(instructionMaxSpan);
        const span = LAYOUT.encode(instruction, b);
        return b.slice(0, span);
    }
}