Raiden Network Smart Contracts Tests

Writing Tests

when implementing a new feature or changing code, make sure your PR also contains tests that cover the changes.
always think about edge cases, go over each Solidity source code line that was changed in your PR and make sure a test covers it if needed.
don’t only test the happy case. If you don't have with pytest.raises(): in your tests, something is wrong

create a test_contract_name.py test file for testing the constructor & all public variables for that contract (including the version) - see TokenNetwork tests
if the contract is big - create multiple test_contract/[contract]_contract_function_name.py test files for testing each contract function separately. E.g. test_channel_open.py (we don't have the contract name here, but we have channel, which is specific enough)

have a version test. E.g. test_version
test TypeErrors - make sure your constructor receives the intended number of arguments, of the intended type. E.g. test_constructor_call for the TokenNetwork contract.
check that all public contract variables indeed have public access. E.g. test_constructor_call_state from the TokenNetworkRegistry contract

Tests usually follow this order when writing them in a file:

test TypeErrors - make sure your function receives the intended number of arguments, of the intended type. E.g. test_open_channel_call
go through each line of code and see whether a test can be written to cover it. E.g. for this line channel_counter += 1; in TokenNetwork.openChannel, this test_counter was added
test_function_name_state - always exists and tests the contract state for when the function is successful (no pytest.raises, but much assert):
- pre-call tests for all contract state variables that are related, all related getter functions
- post-call tests for all contract state variables that are related, all related getter functions, comparing to the pre-call ones
- E.g. test_open_channel_state
- some of these checks are written as fixtures and reused by tests. You can find them in fixtures/channel.py E.g. common_settle_state_tests
tests for each event. E.g. test_open_channel_event

usually, for testing some contract functions, the contract needs to be in a specific state. There are fixtures that provide the state that we need. E.g. for testing channel deposits, we first need to create_channel. These helper fixtures can be found in fixtures/channel.py