Airdrop: contract metadata extension (#640)

add contract metadata extension

Author: kumaryash90

contracts/prebuilts/unaudited/airdrop/Airdrop.sol

@@ -20,12 +20,13 @@ import "@solady/src/utils/SignatureCheckerLib.sol";
 
 import { Initializable } from "../../../extension/Initializable.sol";
 import { Ownable } from "../../../extension/Ownable.sol";
+import { ContractMetadata } from "../../../extension/ContractMetadata.sol";
 
 import "../../../eip/interface/IERC20.sol";
 import "../../../eip/interface/IERC721.sol";
 import "../../../eip/interface/IERC1155.sol";
 
-contract Airdrop is EIP712, Initializable, Ownable {
+contract Airdrop is EIP712, Initializable, Ownable, ContractMetadata {
     /*///////////////////////////////////////////////////////////////
                             State, constants & structs
     //////////////////////////////////////////////////////////////*/
@@ -127,8 +128,9 @@ contract Airdrop is EIP712, Initializable, Ownable {
         _disableInitializers();
     }
 
-    function initialize(address _defaultAdmin) external initializer {
+    function initialize(address _defaultAdmin, string memory _contractURI) external initializer {
         _setupOwner(_defaultAdmin);
+        _setupContractURI(_contractURI);
     }
 
     /*///////////////////////////////////////////////////////////////
@@ -510,6 +512,11 @@ contract Airdrop is EIP712, Initializable, Ownable {
         return msg.sender == owner();
     }
 
+    /// @dev Checks whether contract metadata can be set in the given execution context.
+    function _canSetContractURI() internal view virtual override returns (bool) {
+        return msg.sender == owner();
+    }
+
     /// @dev Domain name and version for EIP-712
     function _domainNameAndVersion() internal pure override returns (string memory name, string memory version) {
         name = "Airdrop";

src/test/airdrop/Airdrop.t.sol

@@ -79,7 +79,7 @@ contract AirdropTest is BaseTest {
 
         address impl = address(new Airdrop());
 
-        airdrop = Airdrop(payable(address(new TWProxy(impl, abi.encodeCall(Airdrop.initialize, (signer))))));
+        airdrop = Airdrop(payable(address(new TWProxy(impl, abi.encodeCall(Airdrop.initialize, (signer, ""))))));
 
         domainSeparator = keccak256(
             abi.encode(TYPE_HASH_EIP712, NAME_HASH, VERSION_HASH, block.chainid, address(airdrop))

src/test/benchmark/AirdropBenchmark.t.sol

@@ -78,7 +78,7 @@ contract AirdropBenchmarkTest is BaseTest {
 
         address impl = address(new Airdrop());
 
-        airdrop = Airdrop(payable(address(new TWProxy(impl, abi.encodeCall(Airdrop.initialize, (signer))))));
+        airdrop = Airdrop(payable(address(new TWProxy(impl, abi.encodeCall(Airdrop.initialize, (signer, ""))))));
 
         domainSeparator = keccak256(
             abi.encode(TYPE_HASH_EIP712, NAME_HASH, VERSION_HASH, block.chainid, address(airdrop))