Brownie Framework and Pytest

Install Brownie

pip install eth-brownie

Create a Brownie Project

To start a brownie project create a directory using command:mkdir and then change directory to the newly created directory using command:cd. Then in the directory run command:brownie init.

Each Brownie project uses the following structure:

• contracts/: Contract sources
• interfaces/: Interface sources
• scripts/: Scripts for deployment and interaction
• tests/: Scripts for testing the project
• build/: where the compiled ABI's are located

When you init a brownie project these folders are empty.

After creating a contract in the contracts folder, you may run the command: brownie compile from anywhere in the directory. This will build the ABI required in the build folder.

The Brownie framework makes use of pytest for testing.

Pytest performs a test discovery process to locate functions that should be included in your project's test suite. Tests must be stored within the tests/ directory of your project, or a subdirectory thereof.

Filenames must match test_*.py or *_test.py. Within the test files, the following methods will be run as tests:

• Functions outside of a class prefixed with test.
• Class methods prefixed with test, where the class is prefixed with Test and does not include an __init__ method.

You may run the tests cases by running: brownie test or brownie test tests or brownie test tests/test_xxx.py

By default, pytest only prints functions that FAILS on assertion

If you'd like to print a all logs you could pass in a "-s" parameter, provided by pytest: E.g. brownie test tests/test_xxx.py -s

There are other brownie specific such as --gas and --coverage

Review: Overall this is a very simple framework. However comparing to the Foundry project you will not be able to see any printed "console.log("xxx")" statements within your contract codes when running the tests. Which might be helpful during a nested call between contracts.