fa2_hooks

Multi Asset Contract

Implementation of the FA2 token contract (TZIP-12) for multiple fungible assets that supports sender/receiver hooks. Receiver/sender hooks behavior is controlled by the permissions.sender and permissions.receiver field values initialized when the FA2 contract is originated. Since the permissions are already represented on-chain as a contract storage field, they are not duplicated in the contract metadata as required by TZIP-12/TZIP-16.

There are two example contracts that implement a receiver hook:

• token_owner_with_hooks.mligo tracks its own token balances within its own storage
• token_sorter.mligo forwards received tokens to other accounts according to its dispatch table.

Project Structure

• multi_asset.md - description
• ligo - contracts code defined in LIGO, smart-contract language for Tezos.
  • ligo/fa2 - FA2 contract interfaces and libraries
  • ligo/fa2_modules - reusable contract implementation modules
  • ligo/fa2_clients - test client contracts interacting with FA2 contract
  • ligo/src folder - reference implementation of the multi-asset FA2 contract, test helper contracts and code.
  • ligo/out folder - multi-asset FA2 contract and helper contract compiled into Michelson.
• tezos_fa2_hooks_tests folder - Python multi_asset contract tests implemented with Pytezos and unittest.

Test Dependencies

LIGO

If you are running the tests, the correct LIGO docker image version will be downloaded automatically when used first time.

See LIGO installation instructions for more details or alternative installation options.

Python3

To run the test, Python 3.6+ and pip 19.0.1+ are required.

Cryptographic Libraries For Pytezos

Pytezos can be installed as tezos_mac_tests module dependency, but it requires to install several cryptographic packages first.

See Pytezos requirements.

Linux

Use apt or your favorite package manager:

sudo apt install libsodium-dev libsecp256k1-dev libgmp-dev

MacOS

Use homebrew:

brew tap cuber/homebrew-libsecp256k1
brew install libsodium libsecp256k1 gmp

Flextesa Sandbox

Tests are configured to run on Flextesa sandbox. There are two helper scripts in tezos_mac_tests module:

• start-sandbox.sh - starts Flextesa sandbox from the docker image
• kill-sandbox.sh - kills running Flextesa sandbox docker container

Installation and Running The Tests

Install dependencies

Cryptographic libraries

brew tap cuber/homebrew-libsecp256k1
brew install libsodium libsecp256k1 gmp

Create Python virtual environment

python3 -m venv tezos_mac_tests_env
source tezos_mac_tests_env/bin/activate

Install tezos_mac_tests Python module

git clone https://github.com/tqtezos/smart-contracts.git
cd smart-contracts/fa2_hooks
pip install -e .

Alternatively, you can install it directly from Github:

pip3 install -e "git+https://github.com/tqtezos/smart-contracts.git#subdirectory=mfa2_hooks&egg=tezos_fa2_hooks_tests"

It will install Pytezos dependencies as well.

Start Tezos Sandbox

flextesa/start-sandbox.sh

When running for the first time, it will download sandbox docker image. It may take a few seconds until sandbox is bootstrapped.

Run The Tests

python -m unittest discover tezos_fa2_hooks_tests