feat: implement ERC-1167 minimal proxies (#289)

contracts/crowdfund/AuctionCrowdfund.sol

@@ -17,7 +17,7 @@ contract AuctionCrowdfund is AuctionCrowdfundBase {
     ///         revert if called outside the constructor.
     /// @param opts Options used to initialize the crowdfund. These are fixed
     ///             and cannot be changed later.
-    function initialize(AuctionCrowdfundOptions memory opts) external payable onlyConstructor {
+    function initialize(AuctionCrowdfundOptions memory opts) external payable onlyInitialize {
         AuctionCrowdfundBase._initialize(opts);
     }
 

contracts/crowdfund/BuyCrowdfund.sol

@@ -78,7 +78,7 @@ contract BuyCrowdfund is BuyCrowdfundBase {
     ///         revert if called outside the constructor.
     /// @param opts Options used to initialize the crowdfund. These are fixed
     ///             and cannot be changed later.
-    function initialize(BuyCrowdfundOptions memory opts) external payable onlyConstructor {
+    function initialize(BuyCrowdfundOptions memory opts) external payable onlyInitialize {
         if (opts.onlyHostCanBuy && opts.governanceOpts.hosts.length == 0) {
             revert MissingHostsError();
         }

contracts/crowdfund/CollectionBatchBuyCrowdfund.sol

@@ -100,7 +100,7 @@ contract CollectionBatchBuyCrowdfund is BuyCrowdfundBase {
     ///             and cannot be changed later.
     function initialize(
         CollectionBatchBuyCrowdfundOptions memory opts
-    ) external payable onlyConstructor {
+    ) external payable onlyInitialize {
         if (opts.governanceOpts.hosts.length == 0) {
             revert MissingHostsError();
         }

contracts/crowdfund/CollectionBuyCrowdfund.sol

@@ -71,9 +71,7 @@ contract CollectionBuyCrowdfund is BuyCrowdfundBase {
     ///         revert if called outside the constructor.
     /// @param opts Options used to initialize the crowdfund. These are fixed
     ///             and cannot be changed later.
-    function initialize(
-        CollectionBuyCrowdfundOptions memory opts
-    ) external payable onlyConstructor {
+    function initialize(CollectionBuyCrowdfundOptions memory opts) external payable onlyInitialize {
         if (opts.governanceOpts.hosts.length == 0) {
             revert MissingHostsError();
         }

contracts/crowdfund/CrowdfundFactory.sol

@@ -1,9 +1,9 @@
 // SPDX-License-Identifier: GPL-3.0
 pragma solidity 0.8.20;
 
+import { Clones } from "openzeppelin/contracts/proxy/Clones.sol";
+
 import { LibRawResult } from "../utils/LibRawResult.sol";
-import { Proxy } from "../utils/Proxy.sol";
-import { Implementation } from "../utils/Implementation.sol";
 import { IGateKeeper } from "../gatekeepers/IGateKeeper.sol";
 
 import { AuctionCrowdfund, AuctionCrowdfundBase } from "./AuctionCrowdfund.sol";
@@ -18,6 +18,7 @@ import { Party } from "../party/Party.sol";
 
 /// @notice Factory used to deploys new proxified `Crowdfund` instances.
 contract CrowdfundFactory {
+    using Clones for address;
     using LibRawResult for bytes;
 
     event BuyCrowdfundCreated(
@@ -72,14 +73,8 @@ contract CrowdfundFactory {
         bytes memory createGateCallData
     ) external payable returns (BuyCrowdfund inst) {
         opts.gateKeeperId = _prepareGate(opts.gateKeeper, opts.gateKeeperId, createGateCallData);
-        inst = BuyCrowdfund(
-            payable(
-                new Proxy{ value: msg.value }(
-                    Implementation(address(crowdfundImpl)),
-                    abi.encodeCall(BuyCrowdfund.initialize, (opts))
-                )
-            )
-        );
+        inst = BuyCrowdfund(address(crowdfundImpl).clone());
+        inst.initialize{ value: msg.value }(opts);
         emit BuyCrowdfundCreated(msg.sender, inst, opts);
     }
 
@@ -96,14 +91,8 @@ contract CrowdfundFactory {
         bytes memory createGateCallData
     ) external payable returns (AuctionCrowdfund inst) {
         opts.gateKeeperId = _prepareGate(opts.gateKeeper, opts.gateKeeperId, createGateCallData);
-        inst = AuctionCrowdfund(
-            payable(
-                new Proxy{ value: msg.value }(
-                    Implementation(address(crowdfundImpl)),
-                    abi.encodeCall(AuctionCrowdfund.initialize, (opts))
-                )
-            )
-        );
+        inst = AuctionCrowdfund(payable(address(crowdfundImpl).clone()));
+        inst.initialize{ value: msg.value }(opts);
         emit AuctionCrowdfundCreated(msg.sender, inst, opts);
     }
 
@@ -121,17 +110,8 @@ contract CrowdfundFactory {
         bytes memory createGateCallData
     ) external payable returns (RollingAuctionCrowdfund inst) {
         opts.gateKeeperId = _prepareGate(opts.gateKeeper, opts.gateKeeperId, createGateCallData);
-        inst = RollingAuctionCrowdfund(
-            payable(
-                new Proxy{ value: msg.value }(
-                    Implementation(address(crowdfundImpl)),
-                    abi.encodeCall(
-                        RollingAuctionCrowdfund.initialize,
-                        (opts, allowedAuctionsMerkleRoot)
-                    )
-                )
-            )
-        );
+        inst = RollingAuctionCrowdfund(payable(address(crowdfundImpl).clone()));
+        inst.initialize{ value: msg.value }(opts, allowedAuctionsMerkleRoot);
         emit RollingAuctionCrowdfundCreated(msg.sender, inst, opts, allowedAuctionsMerkleRoot);
     }
 
@@ -147,14 +127,8 @@ contract CrowdfundFactory {
         bytes memory createGateCallData
     ) external payable returns (CollectionBuyCrowdfund inst) {
         opts.gateKeeperId = _prepareGate(opts.gateKeeper, opts.gateKeeperId, createGateCallData);
-        inst = CollectionBuyCrowdfund(
-            payable(
-                new Proxy{ value: msg.value }(
-                    Implementation(address(crowdfundImpl)),
-                    abi.encodeCall(CollectionBuyCrowdfund.initialize, (opts))
-                )
-            )
-        );
+        inst = CollectionBuyCrowdfund(address(crowdfundImpl).clone());
+        inst.initialize{ value: msg.value }(opts);
         emit CollectionBuyCrowdfundCreated(msg.sender, inst, opts);
     }
 
@@ -170,14 +144,8 @@ contract CrowdfundFactory {
         bytes memory createGateCallData
     ) external payable returns (CollectionBatchBuyCrowdfund inst) {
         opts.gateKeeperId = _prepareGate(opts.gateKeeper, opts.gateKeeperId, createGateCallData);
-        inst = CollectionBatchBuyCrowdfund(
-            payable(
-                new Proxy{ value: msg.value }(
-                    Implementation(address(crowdfundImpl)),
-                    abi.encodeCall(CollectionBatchBuyCrowdfund.initialize, (opts))
-                )
-            )
-        );
+        inst = CollectionBatchBuyCrowdfund(address(crowdfundImpl).clone());
+        inst.initialize{ value: msg.value }(opts);
         emit CollectionBatchBuyCrowdfundCreated(msg.sender, inst, opts);
     }
 
@@ -227,16 +195,12 @@ contract CrowdfundFactory {
             crowdfundOpts.gateKeeperId,
             createGateCallData
         );
-        inst = InitialETHCrowdfund(
-            payable(
-                new Proxy{ value: msg.value }(
-                    Implementation(address(crowdfundImpl)),
-                    abi.encodeCall(
-                        InitialETHCrowdfund.initialize,
-                        (crowdfundOpts, partyOpts, customMetadataProvider, customMetadata)
-                    )
-                )
-            )
+        inst = InitialETHCrowdfund(address(crowdfundImpl).clone());
+        inst.initialize{ value: msg.value }(
+            crowdfundOpts,
+            partyOpts,
+            customMetadataProvider,
+            customMetadata
         );
         emit InitialETHCrowdfundCreated(msg.sender, inst, inst.party(), crowdfundOpts, partyOpts);
     }
@@ -253,14 +217,8 @@ contract CrowdfundFactory {
         bytes memory createGateCallData
     ) external payable returns (ReraiseETHCrowdfund inst) {
         opts.gateKeeperId = _prepareGate(opts.gateKeeper, opts.gateKeeperId, createGateCallData);
-        inst = ReraiseETHCrowdfund(
-            payable(
-                new Proxy{ value: msg.value }(
-                    Implementation(address(crowdfundImpl)),
-                    abi.encodeCall(ReraiseETHCrowdfund.initialize, (opts))
-                )
-            )
-        );
+        inst = ReraiseETHCrowdfund(address(crowdfundImpl).clone());
+        inst.initialize{ value: msg.value }(opts);
         emit ReraiseETHCrowdfundCreated(msg.sender, inst, opts);
     }
 

contracts/crowdfund/InitialETHCrowdfund.sol

@@ -108,7 +108,7 @@ contract InitialETHCrowdfund is ETHCrowdfundBase {
         ETHPartyOptions memory partyOpts,
         MetadataProvider customMetadataProvider,
         bytes memory customMetadata
-    ) external payable onlyConstructor {
+    ) external payable onlyInitialize {
         // Create party the initial crowdfund will be for.
         Party party_ = _createParty(partyOpts, customMetadataProvider, customMetadata);
 

contracts/crowdfund/ReraiseETHCrowdfund.sol

@@ -63,7 +63,7 @@ contract ReraiseETHCrowdfund is ETHCrowdfundBase, CrowdfundNFT {
     /// @notice Initializer to be delegatecalled by `Proxy` constructor. Will
     ///         revert if called outside the constructor.
     /// @param opts The options to initialize the crowdfund with.
-    function initialize(ETHCrowdfundOptions memory opts) external payable onlyConstructor {
+    function initialize(ETHCrowdfundOptions memory opts) external payable onlyInitialize {
         // Initialize the crowdfund.
         ETHCrowdfundBase._initialize(opts);
 

contracts/crowdfund/RollingAuctionCrowdfund.sol

@@ -58,7 +58,7 @@ contract RollingAuctionCrowdfund is AuctionCrowdfundBase {
     function initialize(
         AuctionCrowdfundBase.AuctionCrowdfundOptions memory opts,
         bytes32 allowedAuctionsMerkleRoot_
-    ) external payable onlyConstructor {
+    ) external payable onlyInitialize {
         // Initialize the base contract.
         AuctionCrowdfundBase._initialize(opts);
 

contracts/party/Party.sol

@@ -36,7 +36,7 @@ contract Party is PartyGovernanceNFT {
     /// @notice Initializer to be delegatecalled by `Proxy` constructor. Will
     ///         revert if called outside the constructor.
     /// @param initData Options used to initialize the party governance.
-    function initialize(PartyInitData memory initData) external onlyConstructor {
+    function initialize(PartyInitData memory initData) external onlyInitialize {
         PartyGovernanceNFT._initialize(
             initData.options.name,
             initData.options.symbol,

contracts/party/PartyFactory.sol

@@ -1,19 +1,21 @@
 // SPDX-License-Identifier: GPL-3.0
 pragma solidity 0.8.20;
 
+import { Clones } from "openzeppelin/contracts/proxy/Clones.sol";
+
 import { IERC721 } from "../tokens/IERC721.sol";
-import { Proxy } from "../utils/Proxy.sol";
 
 import { Party } from "./Party.sol";
 import { IPartyFactory } from "./IPartyFactory.sol";
 import { IGlobals } from "../globals/IGlobals.sol";
 import { LibGlobals } from "../globals/LibGlobals.sol";
-import { Implementation } from "../utils/Implementation.sol";
 import { MetadataRegistry } from "../renderers/MetadataRegistry.sol";
 import { MetadataProvider } from "../renderers/MetadataProvider.sol";
 
 /// @notice Factory used to deploy new proxified `Party` instances.
 contract PartyFactory is IPartyFactory {
+    using Clones for address;
+
     error NoAuthorityError();
 
     // The `Globals` contract storing global configuration values. This contract
@@ -46,14 +48,8 @@ contract PartyFactory is IPartyFactory {
             authorities: authorities,
             rageQuitTimestamp: rageQuitTimestamp
         });
-        party = Party(
-            payable(
-                new Proxy(
-                    Implementation(address(partyImpl)),
-                    abi.encodeCall(Party.initialize, (initData))
-                )
-            )
-        );
+        party = Party(payable(address(partyImpl).clone()));
+        party.initialize(initData);
         emit PartyCreated(party, opts, preciousTokens, preciousTokenIds, msg.sender);
     }
 

contracts/proposals/ProposalExecutionEngine.sol

@@ -328,7 +328,7 @@ contract ProposalExecutionEngine is
             );
         }
         _initProposalImpl(newImpl, initData);
-        emit ProposalEngineImplementationUpgraded(address(IMPL), expectedImpl);
+        emit ProposalEngineImplementationUpgraded(address(implementation), expectedImpl);
     }
 
     // Retrieve the explicit storage bucket for the ProposalExecutionEngine logic.

contracts/utils/Implementation.sol

@@ -3,28 +3,41 @@ pragma solidity 0.8.20;
 
 // Base contract for all contracts intended to be delegatecalled into.
 abstract contract Implementation {
+    event Initialized();
+
+    error AlreadyInitialized();
     error OnlyDelegateCallError();
-    error OnlyConstructorError();
 
-    address public immutable IMPL;
+    /// @notice The address of the implementation contract.
+    address public immutable implementation;
+
+    /// @notice Whether or not the implementation has been initialized.
+    bool public initialized;
 
     constructor() {
-        IMPL = address(this);
+        implementation = address(this);
     }
 
     // Reverts if the current function context is not inside of a delegatecall.
     modifier onlyDelegateCall() virtual {
-        if (address(this) == IMPL) {
+        if (address(this) == implementation) {
             revert OnlyDelegateCallError();
         }
         _;
     }
 
-    // Reverts if the current function context is not inside of a constructor.
-    modifier onlyConstructor() {
-        if (address(this).code.length != 0) {
-            revert OnlyConstructorError();
-        }
+    modifier onlyInitialize() {
+        if (initialized) revert AlreadyInitialized();
+
+        initialized = true;
+        emit Initialized();
+
         _;
     }
+
+    /// @notice The address of the implementation contract.
+    /// @dev This is an alias for `implementation` for backwards compatibility.
+    function IMPL() external view returns (address) {
+        return implementation;
+    }
 }