Ethereum solidity development is still in it's early phase. But if you've ever written Solidity before, you know that testing it can be a pain. Truffle does a fine job compiling and deploying Solidity smart contracts, but Truffle's testing framework is slow and usually not helpful. With espresso we're trying to make Solidity testing easier, speedier, and more fun.
What it does
- Test parallelization
- Hot-reloading and running of tests (with a --watch flag)
- Isolated test RPC, so you don't have to have an RPC like ganache running or muddy your development RPC
- Backwards compatibility with truffle test
How we built it
espresso is a combination of many tools already being used in development and testing, namely parts of Truffle and Mocha. It relies on the nifty mocha-parallel-tests library for parallelizing the running of test files, and the testing RPC is created using Ganache.
Challenges we ran into
To list a few:
- Integrating with some of Truffle's internal libraries (i.e. truffle-compile) while still building something new
- Error handling and printing output for tests running in parallel
- Watching arbitrary JS test files and Solidity smart contract files and re-running tests accordingly
- Writing a wrapper around Truffle's config class so we can use
truffle.jsfor projects that have it and generate a valid Truffle config for ones that don't
Accomplishments that we're proud of
Successfully compiling and running one folder of Open Zeppelin tests—and doing it almost twice as fast as Open Zeppelin's implementation of Truffle.