packages/resolver/solidity/AssertAddress.sol
//SPDX-License-Identifier: MIT
pragma solidity >= 0.4.15 < 0.9.0;
library AssertAddress {
// Constant: ADDRESS_NULL
// The null address: 0
address constant ADDRESS_NULL = 0x0000000000000000000000000000000000000000;
/*
Event: TestEvent
Fired when an assertion is made.
Params:
result (bool) - Whether or not the assertion holds.
message (string) - A message to display if the assertion does not hold.
*/
event TestEvent(bool indexed result, string message);
// ************************************** address **************************************
/*
Function: equal(address)
Assert that two addresses are equal.
: A == B
Params:
A (address) - The first address.
B (address) - The second address.
message (string) - A message that is sent if the assertion fails.
Returns:
result (bool) - The result.
*/
function equal(address a, address b, string memory message) public returns (bool result) {
result = (a == b);
_report(result, message);
}
/*
Function: notEqual(address)
Assert that two addresses are not equal.
: A != B
Params:
A (address) - The first address.
B (address) - The second address.
message (string) - A message that is sent if the assertion fails.
Returns:
result (bool) - The result.
*/
function notEqual(address a, address b, string memory message) public returns (bool result) {
result = (a != b);
_report(result, message);
}
/*
Function: isZero(address)
Assert that an address is zero.
: addr == ADDRESS_NULL
Params:
addr (address) - The address.
message (string) - A message that is sent if the assertion fails.
Returns:
result (bool) - The result.
*/
function isZero(address addr, string memory message) public returns (bool result) {
result = (addr == ADDRESS_NULL);
_report(result, message);
}
/*
Function: isNotZero(address)
Assert that an address is not zero.
: addr != ADDRESS_NULL
Params:
addr (address) - The address.
message (string) - A message that is sent if the assertion fails.
Returns:
result (bool) - The result.
*/
function isNotZero(address addr, string memory message) public returns (bool result) {
result = (addr != ADDRESS_NULL);
_report(result, message);
}
/******************************** internal ********************************/
/*
Function: _report
Internal function for triggering <TestEvent>.
Params:
result (bool) - The test result (true or false).
message (string) - The message that is sent if the assertion fails.
*/
function _report(bool result, string memory message) internal {
if(result)
emit TestEvent(true, "");
else
emit TestEvent(false, message);
}
}