Diamond pattern (EIP-2535) in Blockchain / Solidity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the DiamondCutFacet contract.

Blockchain / Solidity

contract DiamondCutFacet is IDiamondCut {
    function diamondCut(
        IDiamondCut.FacetCut[] memory _diamondCut,
        address _init,
        bytes memory _calldata
    ) external override [1] {
        // Implementation
    }
}

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Apure

Bpublic

Cexternal

Dinternal

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'public' instead of 'external' causes mismatch with interface.

Using 'internal' or 'private' makes the function inaccessible externally.

The diamondCut function must be declared as external to match the interface and allow external calls.

2fill in blank

medium

Complete the code to add a facet address to the diamond storage.

Blockchain / Solidity

library LibDiamond {
    struct FacetAddressAndSelectorPosition {
        address facetAddress;
        uint16 selectorPosition;
    }

    struct DiamondStorage {
        mapping(bytes4 => FacetAddressAndSelectorPosition) selectorToFacetAndPosition;
        address[] facetAddresses;
    }

    function diamondStorage() internal pure returns (DiamondStorage storage ds) {
        bytes32 position = keccak256("diamond.standard.diamond.storage");
        assembly {
            ds.slot := position
        }
    }

    function addFacetAddress(address _facetAddress) internal {
        DiamondStorage storage ds = diamondStorage();
        ds.facetAddresses.[1](_facetAddress);
    }
}

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Apush

Bappend

Cadd

Dinsert

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'append' which is not a Solidity array method.

Using 'add' or 'insert' which do not exist for arrays.

To add an element to a dynamic array in Solidity, use the push method.

3fill in blank

hard

Fix the error in the diamondCut function signature to match the interface.

Blockchain / Solidity

function diamondCut(
    IDiamondCut.FacetCut[] memory _diamondCut,
    address _init,
    bytes memory _calldata
) external override [1] {
    // Implementation
}

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Apure

Bpayable

Cview

Dnonpayable

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting 'payable' causes the function to reject Ether transfers.

Using 'pure' or 'view' is incorrect because the function modifies state.

The diamondCut function must be declared payable to accept Ether during the call, as per the EIP-2535 specification.

4fill in blank

hard

Fill both blanks to complete the diamondCut function call and event emission.

Blockchain / Solidity

function diamondCut(
    IDiamondCut.FacetCut[] memory _diamondCut,
    address _init,
    bytes memory _calldata
) external override payable {
    LibDiamond.diamondCut(_diamondCut, _init, _calldata);
    emit [1](_diamondCut, _init, _calldata);
}

// Event declaration
event [2](IDiamondCut.FacetCut[] _diamondCut, address _init, bytes _calldata);

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ADiamondCut

BCutDiamond

CDiamondUpdate

DCutEvent

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect event names causes compilation or runtime errors.

Mismatch between event declaration and emission.

The event emitted after diamondCut is named DiamondCut as per the EIP-2535 standard.

5fill in blank

hard

Fill all three blanks to complete the diamondCut function call with correct parameters and event emission.

Blockchain / Solidity

function diamondCut(
    IDiamondCut.FacetCut[] memory [1],
    address [2],
    bytes memory [3]
) external override payable {
    LibDiamond.diamondCut([1], [2], [3]);
    emit DiamondCut([1], [2], [3]);
}

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A_diamondCut

B_init

C_calldata

D_data

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent parameter names causes errors.

Using '_data' instead of '_calldata' is incorrect.

The parameters and event arguments must use the exact variable names _diamondCut, _init, and _calldata as declared.