DSTest Reference
Dappsys Test (DSTest for short) provides basic logging and assertion functionality. It is included in the Forge Standard Library.
To get access to the functions, import forge-std/Test.sol and inherit from Test in your test contract:
import "forge-std/Test.sol";
contract ContractTest is Test {
// ... tests ...
}
Logging
This is a complete overview of all the available logging events. For detailed descriptions and example usage, see below.
event log (string);
event logs (bytes);
event log_address (address);
event log_bytes32 (bytes32);
event log_int (int);
event log_uint (uint);
event log_bytes (bytes);
event log_string (string);
event log_named_address (string key, address val);
event log_named_bytes32 (string key, bytes32 val);
event log_named_decimal_int (string key, int val, uint decimals);
event log_named_decimal_uint (string key, uint val, uint decimals);
event log_named_int (string key, int val);
event log_named_uint (string key, uint val);
event log_named_bytes (string key, bytes val);
event log_named_string (string key, string val);
Logging events
This section documents all events for logging and provides usage examples.
log
event log(string);
Example
emit log("here");
// here
logs
event logs(bytes);
Example
emit logs(bytes("abcd"));
// 0x6162636400000000000000000000000000000000000000000000000000000000
log_<type>
event log_<type>(<type>);
Where <type> can be address, bytes32, int, uint, bytes, string
Example
uint256 amount = 1 ether;
emit log_uint(amount);
// 1000000000000000000
log_named_<type>
event log_named_<type>(string key, <type> val);
Where <type> can be address, bytes32, int, uint, bytes, string
Example
uint256 amount = 1 ether;
emit log_named_uint("Amount", amount);
// amount: 1000000000000000000
log_named_decimal_<type>
event log_named_decimal_<type>(string key, <type> val, uint decimals);
Where <type> can be int, uint
Example
uint256 amount = 1 ether;
emit log_named_decimal_uint("Amount", amount, 18);
// amount: 1.000000000000000000
Asserting
This is a complete overview of all the available assertion functions. For detailed descriptions and example usage, see below.
// Assert the `condition` is true
function assertTrue(bool condition) internal;
function assertTrue(bool condition, string memory err) internal;
// Assert `a` is equal to `b`
function assertEq(address a, address b) internal;
function assertEq(address a, address b, string memory err) internal;
function assertEq(bytes32 a, bytes32 b) internal;
function assertEq(bytes32 a, bytes32 b, string memory err) internal;
function assertEq(int a, int b) internal;
function assertEq(int a, int b, string memory err) internal;
function assertEq(uint a, uint b) internal;
function assertEq(uint a, uint b, string memory err) internal;
function assertEqDecimal(int a, int b, uint decimals) internal;
function assertEqDecimal(int a, int b, uint decimals, string memory err) internal;
function assertEqDecimal(uint a, uint b, uint decimals) internal;
function assertEqDecimal(uint a, uint b, uint decimals, string memory err) internal;
function assertEq(string memory a, string memory b) internal;
function assertEq(string memory a, string memory b, string memory err) internal;
function assertEq32(bytes32 a, bytes32 b) internal;
function assertEq32(bytes32 a, bytes32 b, string memory err) internal;
function assertEq0(bytes memory a, bytes memory b) internal;
function assertEq0(bytes memory a, bytes memory b, string memory err) internal;
// Assert `a` is greater than `b`
function assertGt(uint a, uint b) internal;
function assertGt(uint a, uint b, string memory err) internal;
function assertGt(int a, int b) internal;
function assertGt(int a, int b, string memory err) internal;
function assertGtDecimal(int a, int b, uint decimals) internal;
function assertGtDecimal(int a, int b, uint decimals, string memory err) internal;
function assertGtDecimal(uint a, uint b, uint decimals) internal;
function assertGtDecimal(uint a, uint b, uint decimals, string memory err) internal;
// Assert `a` is greater than or equal to `b`
function assertGe(uint a, uint b) internal;
function assertGe(uint a, uint b, string memory err) internal;
function assertGe(int a, int b) internal;
function assertGe(int a, int b, string memory err) internal;
function assertGeDecimal(int a, int b, uint decimals) internal;
function assertGeDecimal(int a, int b, uint decimals, string memory err) internal;
function assertGeDecimal(uint a, uint b, uint decimals) internal;
function assertGeDecimal(uint a, uint b, uint decimals, string memory err) internal;
// Assert `a` is lesser than `b`
function assertLt(uint a, uint b) internal;
function assertLt(uint a, uint b, string memory err) internal;
function assertLt(int a, int b) internal;
function assertLt(int a, int b, string memory err) internal;
function assertLtDecimal(int a, int b, uint decimals) internal;
function assertLtDecimal(int a, int b, uint decimals, string memory err) internal;
function assertLtDecimal(uint a, uint b, uint decimals) internal;
function assertLtDecimal(uint a, uint b, uint decimals, string memory err) internal;
// Assert `a` is lesser than or equal to `b`
function assertLe(uint a, uint b) internal;
function assertLe(uint a, uint b, string memory err) internal;
function assertLe(int a, int b) internal;
function assertLe(int a, int b, string memory err) internal;
function assertLeDecimal(int a, int b, uint decimals) internal;
function assertLeDecimal(int a, int b, uint decimals, string memory err) internal;
function assertLeDecimal(uint a, uint b, uint decimals) internal;
function assertLeDecimal(uint a, uint b, uint decimals, string memory err) internal;
// Asserts `a` is approximately equal to `b` with delta in absolute value.
function assertApproxEqAbs(uint256 a, uint256 b, uint256 maxDelta) internal;
function assertApproxEqAbs(uint256 a, uint256 b, uint256 maxDelta, string memory err) internal;
// Asserts `a` is approximately equal to `b` with delta in percentage, where `1e18` is 100%.
function assertApproxEqRel(uint256 a, uint256 b, uint256 maxPercentDelta) internal;
function assertApproxEqRel(uint256 a, uint256 b, uint256 maxPercentDelta, string memory err) internal;
Assertion functions
This section documents all functions for asserting and provides usage examples.
assertTrue
function assertTrue(bool condition) internal;
Asserts the condition is true.
Example
bool success = contract.fun();
assertTrue(success);
assertEq
function assertEq(<type> a, <type> b) internal;
Where <type> can be address, bytes32, int, uint
Asserts a is equal to b.
Example
uint256 a = 1 ether;
uint256 b = 1e18 wei;
assertEq(a, b);
assertEqDecimal
function assertEqDecimal(<type> a, <type> b, uint decimals) internal;
Where <type> can be int, uint
Asserts a is equal to b.
Example
uint256 a = 1 ether;
uint256 b = 1e18 wei;
assertEqDecimal(a, b, 18);
assertEq32
function assertEq32(bytes32 a, bytes32 b) internal;
Asserts a is equal to b.
Example
assertEq(bytes32("abcd"), 0x6162636400000000000000000000000000000000000000000000000000000000);
assertEq0
function assertEq0(bytes a, bytes b) internal;
Asserts a is equal to b.
Example
string memory name1 = "Alice";
string memory name2 = "Bob";
assertEq0(bytes(name1), bytes(name2)); // [FAIL]
assertGt
function assertGt(<type> a, <type> b) internal;
Where <type> can be int, uint
Asserts a is greater than b.
Example
uint256 a = 2 ether;
uint256 b = 1e18 wei;
assertGt(a, b);
assertGtDecimal
function assertGtDecimal(<type> a, <type> b, uint decimals) internal;
Where <type> can be int, uint
Asserts a is greater than b.
Example
uint256 a = 2 ether;
uint256 b = 1e18 wei;
assertGtDecimal(a, b, 18);
assertGe
function assertGe(<type> a, <type> b) internal;
Where <type> can be int, uint
Asserts a is greater than or equal to b.
Example
uint256 a = 1 ether;
uint256 b = 1e18 wei;
assertGe(a, b);
assertGeDecimal
function assertGeDecimal(<type> a, <type> b, uint decimals) internal;
Where <type> can be int, uint
Asserts a is greater than or equal to b.
Example
uint256 a = 1 ether;
uint256 b = 1e18 wei;
assertGeDecimal(a, b, 18);
assertLt
function assertLt(<type> a, <type> b) internal;
Where <type> can be int, uint
Asserts a is lesser than b.
Example
uint256 a = 1 ether;
uint256 b = 2e18 wei;
assertLt(a, b);
assertLtDecimal
function assertLtDecimal(<type> a, <type> b, uint decimals) internal;
Where <type> can be int, uint
Asserts a is lesser than b.
Example
uint256 a = 1 ether;
uint256 b = 2e18 wei;
assertLtDecimal(a, b, 18);
assertLe
function assertLe(<type> a, <type> b) internal;
Where <type> can be int, uint
Asserts a is lesser than or equal to b.
Example
uint256 a = 1 ether;
uint256 b = 1e18 wei;
assertLe(a, b);
assertLeDecimal
function assertLeDecimal(<type> a, <type> b, uint decimals) internal;
Where <type> can be int, uint
Asserts a is lesser than or equal to b.
Example
uint256 a = 1 ether;
uint256 b = 1e18 wei;
assertLeDecimal(a, b, 18);
assertApproxEqAbs
function assertApproxEqAbs(<type> a, <type> b, uint256 maxDelta) internal;
Where <type> can be int, uint
Asserts a is approximately equal to b with delta in absolute value.
Example
function testFail () external {
uint256 a = 100;
uint256 b = 200;
assertApproxEqAbs(a, b, 90);
}
assertApproxEqRel
function assertApproxEqRel(<type> a, <type> b, uint256 maxPercentDelta) internal;
Where <type> can be int, uint
Asserts a is approximately equal to b with delta in percentage, where 1e18 is 100%.
Example
function testFail () external {
uint256 a = 100;
uint256 b = 200;
assertApproxEqRel(a, b, 0.4e18);
}
ℹ️ Information
You can pass a custom error message to the above functions by providing an additional parameter
string err.