02_non_native_programs

🛹 Demo 2: Building Non-Native Programs

tl; dr

• In the previous demo, we used @solana/web3.js's SystemProgram.transfer() function to create an instruction to send SOL.

• In this demo, we will be working with non-native programs, and specifying how to create creating instructions that are structured to match the corresponding program.

---

Setup

• Run npm install from the root of the project.
• Create an .env file, similar to the previous demo.

---

Understanding TransactionInstruction

• With @solana/web3, non-native instructions can be created with the TransactionInstruction constructor.

• This constructor takes a single argument of the data type TransactionInstructionCtorFields, with:

  • an array of keys of type AccountMeta, where each object represents an account that will be read from or written to during a transaction's execution containing =
    • pubkey, the public key of the account
    • isSigner, a boolean representing whether or not the account is a signer on the transaction
    • isWritable, a boolean representing whether or not the account is written to during the transaction's execution
  • programId, the public key for the program being called
  • an optional Buffer containing data to pass to the program

export type TransactionInstructionCtorFields = {
  keys: Array<AccountMeta>;
  programId: PublicKey;
  data?: Buffer;
};

• To illustrate this concept, let's create a script to ping an on-chain program, incrementing a counter each time it is pinged.
• This program exists on the Solana Devnet at address ChT1B39WKLS8qUrkLvFDXMhEJ4F1XZzwUNHUt4AU9aVa and stores its data in a specific account in the address Ah9K7dQ8EHaZqcAsgBW8w37yN2eAy3koFmUn4x3CJtod.

import { 
    clusterApiUrl,
    Connection,
    TransactionInstruction,
    PublicKey,
    Transaction,
    sendAndConfirmTransaction,
    LAMPORTS_PER_SOL
  } from "@solana/web3.js";
import { 
    getKeypairFromEnvironment, 
    airdropIfRequired 
} from "@solana-developers/helpers";
import "dotenv/config"

// Get the sender's keypair and create a connection to the devnet cluster
const sender = getKeypairFromEnvironment('KEYPAIR_SECRET')
const connection = new Connection(clusterApiUrl('devnet'))

// Air drop SOL to the sender's account if required
const airdrop = await airdropIfRequired(
  connection,
  sender.publicKey,
  1 * LAMPORTS_PER_SOL,
  0.5 * LAMPORTS_PER_SOL,
);

// Get the program's address and the program data account's address
const PING_PROGRAM_ADDRESS = new PublicKey('ChT1B39WKLS8qUrkLvFDXMhEJ4F1XZzwUNHUt4AU9aVa')
const PING_PROGRAM_DATA_ADDRESS =  new PublicKey('Ah9K7dQ8EHaZqcAsgBW8w37yN2eAy3koFmUn4x3CJtod')

// Create a new transaction, then initialize a PublicKey for the 
// program account, and another for the data account
const transaction = new Transaction()
const programId = new PublicKey(PING_PROGRAM_ADDRESS)
const pingProgramDataId = new PublicKey(PING_PROGRAM_DATA_ADDRESS)

// Create the instruction, which needs to include the public key for 
// the Ping program and an array with all the accounts that will be 
// read from or written to. In this example program, only the data 
// account referenced above is needed.
const instruction = new TransactionInstruction({
  keys: [
    {
      pubkey: pingProgramDataId,
      isSigner: false,
      isWritable: true
    },
  ],
  programId
})

// Add the instruction to the transaction we created. 
// Then, call sendAndConfirmTransaction() 
transaction.add(instruction)

const signature = await sendAndConfirmTransaction(
  connection,
  transaction,
  [sender]
)
console.log(`✅ Transaction completed! Signature is ${signature}`)
console.log(`You can view your transaction on Solana Explorer at:\nhttps://explorer.solana.com/tx/${signature}?cluster=devnet`)

• Run this code with:

npx esrun tests/ping.ts

• Now copy the transaction signature and paste into the search on Solana explorer to find details and logs about the transaction, including how many times the program has been pinged.

> Program logged: "Pinged 7982 time(s)!"
> Program consumed: 1396 of 200000 compute units