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

import * as anchor from "@project-serum/anchor";
import { 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 program = anchor.workspace.PdaRentPayer as anchor.Program<PdaRentPayer>;

  function deriveRentVaultPda() {
      const pda = anchor.web3.PublicKey.findProgramAddressSync(
          [Buffer.from("rent_vault")],
          program.programId,
      )
      console.log(`PDA: ${pda[0].toBase58()}`)
      return pda
  }

  it("Initialize the Rent Vault", async () => {
      const [rentVaultPda, _] = deriveRentVaultPda();
      await program.methods.initRentVault(new anchor.BN(1000000000))
        .accounts({
          rentVault: rentVaultPda,
          payer: wallet.publicKey,
        })
        .signers([wallet.payer])
        .rpc()
  });

  it("Create a new account using the Rent Vault", async () => {
      const newAccount = anchor.web3.Keypair.generate();
      const [rentVaultPda, _] = deriveRentVaultPda();
      await program.methods.createNewAccount()
        .accounts({
          newAccount: newAccount.publicKey,
          rentVault: rentVaultPda,
        })
        .signers([wallet.payer])
        .rpc()
  });
});