def check_transfer(contract, sender, receiver, amount):
sender_balance = call_function(contract, 'balanceOf', [sender])
receiver_balance = call_function(contract, 'balanceOf', [receiver])
tx_hash = transact_function(sender, contract, 'transfer',
[receiver, amount])
contract.web3.eth.waitForTransactionReceipt(tx_hash)
new_sender_balance = call_function(contract, 'balanceOf', [sender])
new_receiver_balance = call_function(contract, 'balanceOf', [receiver])
# check that balances are correct after transfer
if sender != receiver:
assert new_sender_balance == sender_balance - amount, \
wrong('balance of sender {} after transfer', new_sender_balance, sender_balance - amount)
assert new_receiver_balance == receiver_balance + amount, \
wrong('balance of receiver {} after transfer'.format(receiver), new_receiver_balance,
receiver_balance + amount)
else:
assert sender_balance == new_sender_balance, \
wrong('balance of address {} after transferring to itself'.format(sender), new_sender_balance,
sender_balance)
# check that Transfer event is emitted correctly
check_event(contract, tx_hash, 'Transfer', {
'from': sender,
'to': receiver,
'tokens': amount
})
def test_enable_transfers(contract, accounts, approvers, spenders):
print('check that enabling transfers works correctly: ', end='')
# non owner account should not be able to enable transfers
owner = call_function(contract, 'owner')
not_owners = [account for account in accounts if account != owner]
for account in not_owners:
assert reverts(transact_function, [account, contract, 'enableTransfers']), \
'non owner account {} should not be able to enable transfers'.format(account)
# owner should be able to enable transfers
tx_hash = transact_function(owner, contract, 'enableTransfers')
check_event(contract, tx_hash, 'TransfersEnabled')
# check that transfer works after enabling transfers
senders = accounts[:2]
receivers = accounts[1:3]
for sender in senders:
for receiver in receivers:
check_transfer(contract, sender, receiver, 1)
# check that transferFrom works after enabling transfers
for approver in approvers:
for spender in spenders:
receiver = accounts[3]
check_transfer_from(contract, approver, spender, receiver, 1)
# check that triggering enableTransfers one more time fails
assert reverts(transact_function, [owner, contract, 'enableTransfers']), \
'owner should not be able to enable transfers when it is already enabled'
print('SUCCESS')
def test_disable_transfers(contract, accounts, approvers, spenders):
print('check that disabling transfers works correctly: ', end='')
# non owner account should not be able to enable transfers
owner = call_function(contract, 'owner')
not_owners = [account for account in accounts if account != owner]
for account in not_owners:
assert reverts(transact_function, [account, contract, 'disableTransfers']), \
'non owner account {} should not be able to disable transfers'.format(account)
# owner should be able to enable transfers
tx_hash = transact_function(owner, contract, 'disableTransfers')
check_event(contract, tx_hash, 'TransfersDisabled')
# check that transfer reverts
senders = accounts[:2]
receivers = accounts[1:3]
for sender in senders:
for receiver in receivers:
assert reverts(transact_function, [sender, contract, 'transfer', [receiver, 1]]), \
'{} should not be able to transfer when transferring is disabled'.format(sender)
# check that transferFrom reverts
for approver in approvers:
for spender in spenders:
receiver = accounts[3]
assert reverts(
transact_function,
[spender, contract, 'transferFrom', [approver, receiver, 1]])
# check that triggering disableTransfers one more time fails
assert reverts(transact_function, [owner, contract, 'disableTransfers']), \
'owner should not be able to disable transfers when it is already disabled'
print('SUCCESS')
def check_approve(contract, approver, spender, amount):
tx_hash = transact_function(approver, contract, 'approve',
[spender, amount])
contract.web3.eth.waitForTransactionReceipt(tx_hash)
allowance = call_function(contract, 'allowance', [approver, spender])
assert allowance == amount, wrong(
'{} allowance for {}'.format(approver, spender), allowance, amount)
# check that Approval event is emitted correctly
check_event(contract, tx_hash, 'Approval', {
'tokenOwner': approver,
'spender': spender,
'tokens': amount
})
def check_transfer_from(contract, approver, spender, receiver, amount):
approver_balance = call_function(contract, 'balanceOf', [approver])
receiver_balance = call_function(contract, 'balanceOf', [receiver])
spender_balance = call_function(contract, 'balanceOf', [spender])
allowance = call_function(contract, 'allowance', [approver, spender])
tx_hash = transact_function(spender, contract, 'transferFrom',
[approver, receiver, amount])
contract.web3.eth.waitForTransactionReceipt(tx_hash)
new_approver_balance = call_function(contract, 'balanceOf', [approver])
new_receiver_balance = call_function(contract, 'balanceOf', [receiver])
new_spender_balance = call_function(contract, 'balanceOf', [spender])
new_allowance = call_function(contract, 'allowance', [approver, spender])
assert new_allowance == allowance - amount, \
wrong('{} allowance to {}'.format(approver, spender), new_allowance, allowance - amount)
# check that balances are correct after transferFrom
if approver != receiver:
assert new_approver_balance == approver_balance - amount, \
wrong('balance of approver {} after transfer', new_approver_balance, approver_balance - amount)
assert new_receiver_balance == receiver_balance + amount, \
wrong('balance of receiver {} after transfer'.format(receiver), new_receiver_balance,
receiver_balance + amount)
else:
assert new_approver_balance == approver_balance, \
wrong('balance of approver {} after transfer to itself'.format(approver), new_approver_balance,
approver_balance)
if spender != receiver and spender != spender:
assert new_spender_balance == spender_balance, \
wrong('balance of spender {} after transfer', new_spender_balance, spender_balance)
# check that Transfer event is emitted correctly
check_event(contract, tx_hash, 'Transfer', {
'from': approver,
'to': receiver,
'tokens': amount
})
def check_adjust_approval(contract, approver, spender, amount):
allowance = call_function(contract, 'allowance', [approver, spender])
if amount >= 0:
function_name = 'increaseApproval'
else:
function_name = 'decreaseApproval'
tx_hash = transact_function(approver, contract, function_name,
[spender, abs(amount)])
contract.web3.eth.waitForTransactionReceipt(tx_hash)
new_allowance = call_function(contract, 'allowance', [approver, spender])
assert new_allowance == allowance + amount, wrong(
'{} allowance for {}'.format(approver, spender), allowance, amount)
# check that Approval event is emitted correctly
check_event(contract, tx_hash, 'Approval', {
'tokenOwner': approver,
'spender': spender,
'tokens': new_allowance
})