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

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

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 anchor.BN(LAMPORTS_PER_SOL)

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