Tests and config

contracts/ERC404.sol

@@ -1,5 +1,5 @@
-//SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
 
 import {IERC721Receiver} from "@openzeppelin/contracts/interfaces/IERC721Receiver.sol";
 import {IERC165} from "@openzeppelin/contracts/interfaces/IERC165.sol";

contracts/ERC404U16.sol

@@ -1,5 +1,5 @@
-//SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
 
 import {IERC721Receiver} from "@openzeppelin/contracts/interfaces/IERC721Receiver.sol";
 import {IERC165} from "@openzeppelin/contracts/interfaces/IERC165.sol";

contracts/examples/ERC404Example.sol

@@ -1,4 +1,4 @@
-//SPDX-License-Identifier: MIT
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";

contracts/examples/ERC404ExampleU16.sol

@@ -1,4 +1,4 @@
-//SPDX-License-Identifier: MIT
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";

contracts/examples/ERC404ExampleUniswapV2.sol

@@ -1,4 +1,4 @@
-//SPDX-License-Identifier: MIT
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";

contracts/examples/ERC404ExampleUniswapV3.sol

@@ -1,4 +1,4 @@
-//SPDX-License-Identifier: MIT
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";

contracts/extensions/ERC404MerkleClaim.sol

@@ -1,5 +1,5 @@
-//SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
 
 import {MerkleProof} from "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
 import {IERC404MerkleClaim} from "./IERC404MerkleClaim.sol";
@@ -20,7 +20,7 @@ abstract contract ERC404MerkleClaim is IERC404MerkleClaim {
     bytes32[] memory proof_,
     address claimer_,
     uint256 value_
-  ) public view returns (bool) {
+  ) public view virtual returns (bool) {
     bytes32 leaf = keccak256(
       bytes.concat(keccak256(abi.encode(claimer_, value_)))
     );
@@ -30,28 +30,30 @@ abstract contract ERC404MerkleClaim is IERC404MerkleClaim {
     return false;
   }
 
-  // To use, override this function in your contract, call
-  // super.airdropMint(proof_) within your override function, then mint tokens.
-  function airdropMint(
+  // Pass in value_ as the amount of tokens to mint in ERC-20 format (i.e. wei, if using decimals 18).
+  function airdropMintERC20(
     bytes32[] memory proof_,
     uint256 value_
   ) public virtual whenAirdropIsOpen {
+    // Validate and record the airdrop claim so they can't claim it twice.
     _validateAndRecordAirdropClaim(proof_, msg.sender, value_);
+    // Mint the user's airdrop to them.
+    _mintERC20(msg.sender, value_);
   }
 
-  function _setAirdropMerkleRoot(bytes32 airdropMerkleRoot_) internal {
+  function _setAirdropMerkleRoot(bytes32 airdropMerkleRoot_) internal virtual {
     airdropMerkleRoot = airdropMerkleRoot_;
   }
 
-  function _toggleAirdropIsOpen() internal {
-    airdropIsOpen = !airdropIsOpen;
+  function _setAirdropIsOpen(bool state_) internal virtual {
+    airdropIsOpen = state_;
   }
 
   function _validateAndRecordAirdropClaim(
     bytes32[] memory proof_,
     address claimer_,
     uint256 value_
-  ) internal {
+  ) internal virtual {
     // Check that the address is eligible.
     if (!verifyProof(proof_, claimer_, value_)) {
       revert NotEligibleForAirdrop();

contracts/extensions/ERC404UniswapV2Exempt.sol

@@ -1,5 +1,5 @@
-//SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
 
 import {ERC404} from "../ERC404.sol";
 import {IUniswapV2Router02} from "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";

contracts/extensions/ERC404UniswapV3Exempt.sol

@@ -1,5 +1,5 @@
-//SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
 
 import {ERC404} from "../ERC404.sol";
 import {IPeripheryImmutableState} from "@uniswap/v3-periphery/contracts/interfaces/IPeripheryImmutableState.sol";

contracts/extensions/IERC404MerkleClaim.sol

@@ -1,5 +1,5 @@
-//SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
 
 interface IERC404MerkleClaim {
   error AirdropAlreadyClaimed();
@@ -12,5 +12,5 @@ interface IERC404MerkleClaim {
     uint256 value_
   ) external view returns (bool);
 
-  function airdropMint(bytes32[] memory proof_, uint256 value_) external;
+  function airdropMintERC20(bytes32[] memory proof_, uint256 value_) external;
 }

contracts/interfaces/IERC404.sol

@@ -1,5 +1,5 @@
-//SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
 
 import {IERC165} from "@openzeppelin/contracts/interfaces/IERC165.sol";
 

contracts/legacy/ERC404Legacy.sol

@@ -1,4 +1,4 @@
-//SPDX-License-Identifier: MIT
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 abstract contract Ownable {

contracts/legacy/Pandora.sol

@@ -1,4 +1,4 @@
-//SPDX-License-Identifier: MIT
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import "./ERC404Legacy.sol";

contracts/lib/DoubleEndedQueue.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 // OpenZeppelin Contracts (last updated v5.0.0) (utils/structs/DoubleEndedQueue.sol)
 // Modified by Pandora Labs to support native uint256 operations
-pragma solidity ^0.8.20;
+pragma solidity 0.8.24;
 
 /**
  * @dev A sequence of items with the ability to efficiently push and pop items (i.e. insert and remove) on both ends of

contracts/lib/ERC20Events.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+pragma solidity 0.8.24;
 
 library ERC20Events {
   event Approval(address indexed owner, address indexed spender, uint256 value);

contracts/lib/ERC721Events.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+pragma solidity 0.8.24;
 
 library ERC721Events {
   event ApprovalForAll(

contracts/lib/PackedDoubleEndedQueue.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 // OpenZeppelin Contracts (last updated v5.0.0) (utils/structs/DoubleEndedQueue.sol)
 // Modified by Pandora Labs to support native packed operations
-pragma solidity ^0.8.20;
+pragma solidity 0.8.24;
 
 /**
  * @dev A sequence of items with the ability to efficiently push and pop items (i.e. insert and remove) on both ends of

contracts/mocks/MinimalERC404.sol

@@ -1,4 +1,4 @@
-//SPDX-License-Identifier: MIT
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";

contracts/mocks/MockInvalidERC721Receiver.sol

@@ -1,5 +1,5 @@
-//SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
 
 contract MockInvalidERC721Receiver {
   function wrongSelector() external pure {

contracts/mocks/MockValidERC721Receiver.sol

@@ -1,5 +1,5 @@
-//SPDX-License-Identifier: MIT
-pragma solidity ^0.8.20;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
 
 import {IERC721Receiver} from "@openzeppelin/contracts/interfaces/IERC721Receiver.sol";
 

hardhat.config.ts

@@ -4,7 +4,28 @@ import "@nomicfoundation/hardhat-toolbox"
 import "hardhat-gas-reporter"
 
 const config: HardhatUserConfig = {
-  solidity: { compilers: [{ version: "0.8.20" }, { version: "0.4.18" }] },
+  solidity: {
+    compilers: [
+      {
+        version: "0.8.24",
+        settings: {
+          optimizer: {
+            enabled: true,
+            runs: 1_000,
+          },
+        },
+      },
+      {
+        version: "0.4.18",
+        settings: {
+          optimizer: {
+            enabled: true,
+            runs: 1_000,
+          },
+        },
+      },
+    ],
+  },
   gasReporter: {
     currency: "USD",
     gasPrice: 21,