GBEC 2021.02.25 sample code

PanicTest.sol

pragma solidity >= 0.8.0;


contract CalledContract {    
    uint[] nums;
    
    function onlyEven(uint256 a) external pure returns(uint) {
        uint b = 300 / a;
        require(b % 2 == 0, "Ups! Reverting");
        return b;
    }
    
    function outOfBounds(uint256 _index) external pure returns(uint) {
         uint8[4] memory someNums = [1, 2, 3, 4];
         return someNums[_index];
    }
    
    function getNums(uint _index) external view returns(uint) {
        return nums[_index];
    }
    
    function addNum(uint num) external {
        nums.push(num);
    }
    
    function popNum() external {
        nums.pop();
    }
}

contract PanicTest {
    event ReturnDataEvent(bytes someData);
    event SuccessEvent(uint _value);
    event CatchEvent(string revertReason);
    event PanicEvent(uint code);

    CalledContract public externalContract;

    constructor() {
        externalContract = new CalledContract();
    }
    
    function execute(uint amount) public {
        try externalContract.onlyEven(amount) returns(uint _value) {
            emit SuccessEvent(_value);
        } catch Error(string memory revertReason) {
            emit CatchEvent(revertReason);
        } catch Panic(uint _code) {
            emit PanicEvent(_code);
        } catch (bytes memory returnData) {
            emit ReturnDataEvent(returnData);
        }
    }
    
    function outOfBoundsTest(uint _index) public {
        try externalContract.outOfBounds(_index) returns(uint _value) {
            emit SuccessEvent(_value);
        } catch Error(string memory revertReason) {
            emit CatchEvent(revertReason);
        } catch Panic(uint _code) {
            emit PanicEvent(_code);
        } catch (bytes memory returnData) {
            emit ReturnDataEvent(returnData);
        }
    }
    
    function getNums(uint _index) external {
         try externalContract.getNums(_index) returns(uint _value) {
            emit SuccessEvent(_value);
        } catch Error(string memory revertReason) {
            emit CatchEvent(revertReason);
        } catch Panic(uint _code) {
            emit PanicEvent(_code);
        } catch (bytes memory returnData) {
            emit ReturnDataEvent(returnData);
        }
    }
    
    function addNum(uint num) external {
         try externalContract.addNum(num) {
            emit SuccessEvent(num);
        } catch Error(string memory revertReason) {
            emit CatchEvent(revertReason);
        } catch Panic(uint _code) {
            emit PanicEvent(_code);
        } catch (bytes memory returnData) {
            emit ReturnDataEvent(returnData);
        }
    }
    
    function popNum() external {
         try externalContract.popNum() {
            emit SuccessEvent(0);
        } catch Error(string memory revertReason) {
            emit CatchEvent(revertReason);
        } catch Panic(uint _code) {
            emit PanicEvent(_code);
        } catch (bytes memory returnData) {
            emit ReturnDataEvent(returnData);
        }
    }
}