# Piggy Bank (Anchor) Complete all tasks below - Implement a piggy bank program - Test locally # Update program id ```shell anchor keys sync ``` # Task 1 - Implement [`lock`](https://github.com/Cyfrin/solana-course/blob/main/apps/piggy/anchor/exercise/programs/piggy/src/lib.rs) - Require `amt` > 0 ```shell require!(amt > 0, error::Error::InvalidAmount); ``` - Ensure expiration is in the future ```shell require!( exp > u64::try_from(clock.unix_timestamp).unwrap(), error::Error::InvalidExpiration ); ``` - Store lock state ```shell let lock = &mut ctx.accounts.lock; lock.dst = ctx.accounts.dst.key(); lock.exp = exp; ``` - Transfer SOL from payer to PDA ```shell let ix = anchor_lang::solana_program::system_instruction::transfer( &ctx.accounts.payer.key(), &ctx.accounts.lock.key(), amt, ); anchor_lang::solana_program::program::invoke( &ix, &[ ctx.accounts.payer.to_account_info(), ctx.accounts.lock.to_account_info(), ctx.accounts.system_program.to_account_info(), ], )?; ``` - Call `instructions::lock` inside `lib.rs` # Task 2 - Implement [`unlock`](https://github.com/Cyfrin/solana-course/blob/main/apps/piggy/anchor/exercise/programs/piggy/src/lib.rs) - Check expiration ```shell require!( u64::try_from(clock.unix_timestamp).unwrap() >= lock.exp, error::Error::LockNotExpired ); ``` - Transfer all lamports to dst ```shell let amt = ctx.accounts.lock.to_account_info().lamports(); **ctx .accounts .lock .to_account_info() .try_borrow_mut_lamports()? -= amt; **ctx .accounts .dst .to_account_info() .try_borrow_mut_lamports()? += amt; ``` # Build ```shell anchor build ``` # Test ```shell anchor test ```