https://en.wikipedia.org/wiki/Dutch_auction

This not code for production usage, need more tests and knowledge for verification. Just interesting task for learning some things from Solana.

Usage example in tests/auction.rs (can be testsed only for target bpf):

cargo test-bpf --test auction -- --nocapture

Easiest way to install tools is to use install tool: https://docs.solana.com/cli/install-solana-cli-tools#use-solanas-install-tool

Unfortunately on M1 I got error for 1.7.1:

$ solana-test-validator --help
dyld: Library not loaded: /usr/local/opt/openssl@1.1/lib/libssl.1.1.dylib
  Referenced from: /Users/kirill/.local/share/solana/install/active_release/bin/solana-test-validator
  Reason: image not found
zsh: abort      solana-test-validator --help

But we also can build binaries from source code:

https://docs.solana.com/cli/install-solana-cli-tools#build-from-source

Before run cargo-install-all.sh we need:

• Checkout to v1.7.1
• Comment line with spl-token-cli installation, because it's not compilable right now due to ring crate: https://github.com/solana-labs/solana/blob/v1.7.1/scripts/cargo-install-all.sh#L135
• Cherry-pick code from https://github.com/solana-labs/solana/pull/17632

Still error on M1 on deploying helloword example:

Error: Deploying program failed: unable to confirm transaction. This can happen in situations such as transaction expiration and insufficient fee-payer funds

We sill would need x86_64 MacOS/Linux for deploying program to local validator 😑.

At least we can run tests on M1.

Unfortunately, little later I was found that my tests are not work on M1 and switched to x86_64 Linux.

First I was need to explore how to work with Tokens in Solana. There was few unclear things mostly related with accounts deriviation and selecting with which keys I should work. But I was able to mint, approve, transfer tokens in ProgramTest, as result I added test to tests/token.rs.

New day — new problem. Our auction depends from time. I found that we can get time in our program from Clock (by calling Clock::get, it's possible because Clock implement Sysvar trait). What I was not able to understand is how to forward time in my tests. I even deployed my small progmram to test validator first time and run it first time, for checking that time is changed. For communicating with validator I added binary bin/rpc-clock.rs (it's sad that methods in RPC client is not async 😞). Finally I found that we can move forward with ProgramTestContext::warp_to_slot.

Our contract we will need move Tokens and SOL between accounts. Calling Between Programs in docs says that we need to use solana_program::program::invoke function. solana-program-library even have example cross-program-invocation.

I tried to call invoke in same way as I would call it outside smart contract, but my test fail with: Program id TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA wasn't found in account_infos. I quickly found that this came from SyscallStubs. Looking on example I noticed feature test-bpf and tried run my test with cargo test-bpf. Error again. There also important note that we are not able to build bpf target once have solana-sdk or other related crate in [dependencies] section. We should use workspaces. TIL.

On next day morning I thought what if I pass called program AccountInfo to invoke? Success. Looks like I did not read docs carefully and this was really unclear for me that we need pass extra AccountInfo.

For simplicity initially I used spl_toke::transfer_checked but anybody should able to call our program and program should able to send Tokens. Obviously we can not reveal auction secret key. This lead us to section Program Derive Address. From docs we know that Pubkey have two methods for deriving address: create_with_seed and create_program_address.

Which we should use? In solana-program-test I found that we need to use create_program_address.

Now we need to move Tokens controlled by contract. Initially I tried use derived address as Tokens store. This block me for few hours because derived address is account which control account with Tokens (which can be created with spl_associated_token_account::create_associated_token_account). As result we will have 3 accounts: auction account, account for tokens, auction derived account which control account with tokens and store SOL from customers.

And for call transfer with new additional sign in program we need to use invoke_signed.

Source code in src directory.