mock-calls.md

mockCalls

Signature

function mockCalls(address where, bytes calldata data, bytes[] calldata retdata) external;

function mockCalls(
    address where,
    uint256 value,
    bytes calldata data,
    bytes[] calldata retdata
) external;

Description

Mocks all calls to an address where if the call data either strictly or loosely matches data and returns different data for each call based on the retdata array values.

See mockCall for more information on mocking calls and matching precedence.

ℹ️ Note

Any invocation of the mocked call beyond the number of elements in retdata will receive the last retdata element in response. clearMockedCalls can be called to clear the mock

Examples

Mocking multiple balanceOf(address) calls:

function testMockCall() public {
    bytes[] memory mocks = new bytes[](2);
    mocks[0] = abi.encode(2 ether);
    mocks[1] = abi.encode(1 ether);

    vm.mockCalls(
        address(0),
        abi.encodeWithSelector(IERC20.balanceOf.selector, address(1)),
        mocks
    );

    assertEq(IERC20(address(0)).balanceOf(address(1)), 2 ether);
    assertEq(IERC20(address(0)).balanceOf(address(1)), 1 ether);
}

Mocking multiple calls with msg.value:

function testMockCallsWithMsgValue() public {
    bytes[] memory mocks = new bytes[](2);
    mocks[0] = abi.encode(2 ether);
    mocks[1] = abi.encode(1 ether);

    vm.mockCalls(
        address(0),
        1 ether,
        abi.encodeWithSelector(DexPool.swapETHForToken.selector),
        mocks
    );

    uint tokenAmount1 = DexPool(address(0)).swapETHForToken{value: 1 ether}();
    uint tokenAmount2 = DexPool(address(0)).swapETHForToken{value: 1 ether}();

    assertEq(tokenAmount1, 2 ether);
    assertEq(tokenAmount2, 1 ether);
}