TESTING.md

Contracts testing options

Revert stack traces

If you want to see helpful stack traces (incl. line number, code snippet) for smart contract reverts, run the tests with:

yarn test:trace

Note: This currently slows down the test runs and is therefore not enabled by default.

Backing Ethereum node

By default, our tests run against an in-process Ganache instance. In order to run the tests against Geth, first follow the instructions in the README for the devnet package to start the devnet Geth node. Then run:

TEST_PROVIDER=geth yarn test

Code coverage

In order to see the Solidity code coverage output generated by @0x/sol-coverage, run:

yarn test:coverage

Gas profiler

In order to profile the gas costs for a specific smart contract call/transaction, you can run the tests in profiler mode.

Note: Traces emitted by ganache have incorrect gas costs so we recommend using Geth for profiling.

TEST_PROVIDER=geth yarn test:profiler

You'll see a warning that you need to explicitly enable and disable the profiler before and after the block of code you want to profile.

import { profiler } from './utils/profiler';
profiler.start();
// Some call to a smart contract
profiler.stop();

Without explicitly starting and stopping the profiler, the profiler output will be too busy, and therefore unusable.