solana-program-examples/basics/pda-rent-payer/anchor/tests/test.ts

import * as anchor from "@coral-xyz/anchor";
import { Keypair, LAMPORTS_PER_SOL, PublicKey } from "@solana/web3.js";
import BN from "bn.js";
import { assert } from "chai";
import type { PdaRentPayer } from "../target/types/pda_rent_payer";

describe("PDA Rent-Payer", () => {
	const provider = anchor.AnchorProvider.env();
	anchor.setProvider(provider);
	const wallet = provider.wallet as anchor.Wallet;
	const connection = provider.connection;
	const program = anchor.workspace.PdaRentPayer as anchor.Program<PdaRentPayer>;

	// PDA for the Rent Vault
	const [rentVaultPDA] = PublicKey.findProgramAddressSync(
		[Buffer.from("rent_vault")],
		program.programId,
	);

	it("Initialize the Rent Vault", async () => {
		// 1 SOL
		const fundAmount = new BN(LAMPORTS_PER_SOL);

		await program.methods
			.initRentVault(fundAmount)
			.accounts({
				payer: wallet.publicKey,
			})
			.rpc();

		// Check rent vault balance
		const accountInfo =
			await program.provider.connection.getAccountInfo(rentVaultPDA);
		assert(accountInfo.lamports === fundAmount.toNumber());
	});

	it("Create a new account using the Rent Vault", async () => {
		// Generate a new keypair for the new account
		const newAccount = new Keypair();

		await program.methods
			.createNewAccount()
			.accounts({
				newAccount: newAccount.publicKey,
			})
			.signers([newAccount])
			.rpc();

		// Minimum balance for rent exemption for new account
		const lamports = await connection.getMinimumBalanceForRentExemption(0);

		// Check that the account was created
		const accountInfo = await connection.getAccountInfo(newAccount.publicKey);
		assert(accountInfo.lamports === lamports);
	});
});