From 079f54eaf1e65f04eb167541b7944c2699fe9eba Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 23 Mar 2023 18:19:51 +0100
Subject: [PATCH 01/20] manualy root ifAdmin function in
 TransparentUpgradeableProxy

---
 contracts/proxy/transparent/ProxyAdmin.sol    |  10 +-
 .../TransparentUpgradeableProxy.sol           | 122 ++++++++----------
 .../TransparentUpgradeableProxy.test.js       |   4 +-
 3 files changed, 64 insertions(+), 72 deletions(-)

diff --git a/contracts/proxy/transparent/ProxyAdmin.sol b/contracts/proxy/transparent/ProxyAdmin.sol
index 839534298b9..1a969819647 100644
--- a/contracts/proxy/transparent/ProxyAdmin.sol
+++ b/contracts/proxy/transparent/ProxyAdmin.sol
@@ -18,7 +18,7 @@ contract ProxyAdmin is Ownable {
      *
      * - This contract must be the admin of `proxy`.
      */
-    function getProxyImplementation(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
+    function getProxyImplementation(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
         // We need to manually run the static call since the getter cannot be flagged as view
         // bytes4(keccak256("implementation()")) == 0x5c60da1b
         (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
@@ -33,7 +33,7 @@ contract ProxyAdmin is Ownable {
      *
      * - This contract must be the admin of `proxy`.
      */
-    function getProxyAdmin(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
+    function getProxyAdmin(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
         // We need to manually run the static call since the getter cannot be flagged as view
         // bytes4(keccak256("admin()")) == 0xf851a440
         (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
@@ -48,7 +48,7 @@ contract ProxyAdmin is Ownable {
      *
      * - This contract must be the current admin of `proxy`.
      */
-    function changeProxyAdmin(TransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
+    function changeProxyAdmin(ITransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
         proxy.changeAdmin(newAdmin);
     }
 
@@ -59,7 +59,7 @@ contract ProxyAdmin is Ownable {
      *
      * - This contract must be the admin of `proxy`.
      */
-    function upgrade(TransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
+    function upgrade(ITransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
         proxy.upgradeTo(implementation);
     }
 
@@ -72,7 +72,7 @@ contract ProxyAdmin is Ownable {
      * - This contract must be the admin of `proxy`.
      */
     function upgradeAndCall(
-        TransparentUpgradeableProxy proxy,
+        ITransparentUpgradeableProxy proxy,
         address implementation,
         bytes memory data
     ) public payable virtual onlyOwner {
diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index 155a22e01f7..ccb436211ec 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -5,6 +5,16 @@ pragma solidity ^0.8.0;
 
 import "../ERC1967/ERC1967Proxy.sol";
 
+interface ITransparentUpgradeableProxy {
+    event Upgraded(address indexed implementation);
+    event AdminChanged(address previousAdmin, address newAdmin);
+    function admin() external returns (address);
+    function implementation() external returns (address);
+    function changeAdmin(address) external;
+    function upgradeTo(address) external;
+    function upgradeToAndCall(address, bytes memory) payable external;
+}
+
 /**
  * @dev This contract implements a proxy that is upgradeable by an admin.
  *
@@ -42,69 +52,57 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
         if (msg.sender == _getAdmin()) {
             _;
         } else {
-            _fallback();
+            super._fallback();
         }
     }
 
     /**
-     * @dev Returns the current admin.
-     *
-     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
-     *
-     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
-     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
-     * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
-     */
-    function admin() external payable ifAdmin returns (address admin_) {
-        _requireZeroValue();
-        admin_ = _getAdmin();
-    }
-
-    /**
-     * @dev Returns the current implementation.
-     *
-     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
-     *
-     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
-     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
-     * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
+     * @dev TODO
      */
-    function implementation() external payable ifAdmin returns (address implementation_) {
-        _requireZeroValue();
-        implementation_ = _implementation();
-    }
-
-    /**
-     * @dev Changes the admin of the proxy.
-     *
-     * Emits an {AdminChanged} event.
-     *
-     * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
-     */
-    function changeAdmin(address newAdmin) external payable virtual ifAdmin {
-        _requireZeroValue();
-        _changeAdmin(newAdmin);
-    }
-
-    /**
-     * @dev Upgrade the implementation of the proxy.
-     *
-     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
-     */
-    function upgradeTo(address newImplementation) external payable ifAdmin {
-        _requireZeroValue();
-        _upgradeToAndCall(newImplementation, bytes(""), false);
-    }
-
-    /**
-     * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
-     * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
-     * proxied contract.
-     *
-     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
-     */
-    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
-        _upgradeToAndCall(newImplementation, data, true);
+    function _fallback() internal virtual override ifAdmin {
+        bytes4 selector = msg.sig;
+        if (selector == ITransparentUpgradeableProxy.admin.selector) {
+            // Returns the current admin.
+            //
+            // TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
+            // https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
+            // `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
+            _requireZeroValue();
+            address admin = _getAdmin();
+            assembly {
+                mstore(0x00, admin)
+                return(0, 0x20)
+            }
+        } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
+            // Returns the current implementation.
+            // TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
+            // https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
+            // `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
+            _requireZeroValue();
+            address implementation = _implementation();
+            assembly {
+                mstore(0x00, implementation)
+                return(0, 0x20)
+            }
+        } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
+            // Changes the admin of the proxy.
+            _requireZeroValue();
+            address newAdmin = abi.decode(msg.data[4:], (address));
+            _changeAdmin(newAdmin);
+        } else if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
+            // Upgrade the implementation of the proxy.
+            _requireZeroValue();
+            address newImplementation = abi.decode(msg.data[4:], (address));
+            _upgradeToAndCall(newImplementation, bytes(""), false);
+        } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
+            // Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
+            // by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
+            // proxied contract.
+            (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
+            _upgradeToAndCall(newImplementation, data, true);
+        } else {
+            revert('TransparentUpgradeableProxy: admin cannot fallback to proxy target');
+        }
     }
 
     /**
@@ -114,14 +112,6 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
         return _getAdmin();
     }
 
-    /**
-     * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
-     */
-    function _beforeFallback() internal virtual override {
-        require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
-        super._beforeFallback();
-    }
-
     /**
      * @dev To keep this contract fully transparent, all `ifAdmin` functions must be payable. This helper is here to
      * emulate some proxy functions being non-payable while still allowing value to pass through.
diff --git a/test/proxy/transparent/TransparentUpgradeableProxy.test.js b/test/proxy/transparent/TransparentUpgradeableProxy.test.js
index 86dd55d32c1..d60a31a21da 100644
--- a/test/proxy/transparent/TransparentUpgradeableProxy.test.js
+++ b/test/proxy/transparent/TransparentUpgradeableProxy.test.js
@@ -2,12 +2,14 @@ const shouldBehaveLikeProxy = require('../Proxy.behaviour');
 const shouldBehaveLikeTransparentUpgradeableProxy = require('./TransparentUpgradeableProxy.behaviour');
 
 const TransparentUpgradeableProxy = artifacts.require('TransparentUpgradeableProxy');
+const ITransparentUpgradeableProxy = artifacts.require('ITransparentUpgradeableProxy');
 
 contract('TransparentUpgradeableProxy', function (accounts) {
   const [proxyAdminAddress, proxyAdminOwner] = accounts;
 
   const createProxy = async function (logic, admin, initData, opts) {
-    return TransparentUpgradeableProxy.new(logic, admin, initData, opts);
+    const { address } = await TransparentUpgradeableProxy.new(logic, admin, initData, opts);
+    return ITransparentUpgradeableProxy.at(address);
   };
 
   shouldBehaveLikeProxy(createProxy, proxyAdminAddress, proxyAdminOwner);

From 48ea529a336786251169155367bfae03900a7245 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 23 Mar 2023 18:23:40 +0100
Subject: [PATCH 02/20] minor improvement

---
 .../TransparentUpgradeableProxy.sol           | 97 +++++++++----------
 1 file changed, 45 insertions(+), 52 deletions(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index ccb436211ec..ed71dd4f3d4 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -46,62 +46,55 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
     }
 
     /**
-     * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
+     * @dev If caller is the admin process the call internally, otherwize transparently fallback to the proxy behavior
      */
-    modifier ifAdmin() {
+    function _fallback() internal virtual override {
         if (msg.sender == _getAdmin()) {
-            _;
-        } else {
-            super._fallback();
-        }
-    }
-
-    /**
-     * @dev TODO
-     */
-    function _fallback() internal virtual override ifAdmin {
-        bytes4 selector = msg.sig;
-        if (selector == ITransparentUpgradeableProxy.admin.selector) {
-            // Returns the current admin.
-            //
-            // TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
-            // https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
-            // `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
-            _requireZeroValue();
-            address admin = _getAdmin();
-            assembly {
-                mstore(0x00, admin)
-                return(0, 0x20)
+            bytes4 selector = msg.sig;
+            if (selector == ITransparentUpgradeableProxy.admin.selector) {
+                // Returns the current admin.
+                //
+                // TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
+                // https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
+                // `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
+                _requireZeroValue();
+                address admin = _getAdmin();
+                assembly {
+                    mstore(0x00, admin)
+                    return(0, 0x20)
+                }
+            } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
+                // Returns the current implementation.
+                // TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
+                // https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
+                // `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
+                _requireZeroValue();
+                address implementation = _implementation();
+                assembly {
+                    mstore(0x00, implementation)
+                    return(0, 0x20)
+                }
+            } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
+                // Changes the admin of the proxy.
+                _requireZeroValue();
+                address newAdmin = abi.decode(msg.data[4:], (address));
+                _changeAdmin(newAdmin);
+            } else if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
+                // Upgrade the implementation of the proxy.
+                _requireZeroValue();
+                address newImplementation = abi.decode(msg.data[4:], (address));
+                _upgradeToAndCall(newImplementation, bytes(""), false);
+            } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
+                // Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
+                // by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
+                // proxied contract.
+                (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
+                _upgradeToAndCall(newImplementation, data, true);
+            } else {
+                revert('TransparentUpgradeableProxy: admin cannot fallback to proxy target');
             }
-        } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
-            // Returns the current implementation.
-            // TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
-            // https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
-            // `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
-            _requireZeroValue();
-            address implementation = _implementation();
-            assembly {
-                mstore(0x00, implementation)
-                return(0, 0x20)
-            }
-        } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
-            // Changes the admin of the proxy.
-            _requireZeroValue();
-            address newAdmin = abi.decode(msg.data[4:], (address));
-            _changeAdmin(newAdmin);
-        } else if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
-            // Upgrade the implementation of the proxy.
-            _requireZeroValue();
-            address newImplementation = abi.decode(msg.data[4:], (address));
-            _upgradeToAndCall(newImplementation, bytes(""), false);
-        } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
-            // Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
-            // by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
-            // proxied contract.
-            (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
-            _upgradeToAndCall(newImplementation, data, true);
         } else {
-            revert('TransparentUpgradeableProxy: admin cannot fallback to proxy target');
+            super._fallback();
         }
     }
 

From 81826a53a3782a4fbe07680b07349ad1f38fc36e Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 23 Mar 2023 18:31:41 +0100
Subject: [PATCH 03/20] split fallback routing

---
 .../TransparentUpgradeableProxy.sol           | 102 ++++++++++++------
 1 file changed, 68 insertions(+), 34 deletions(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index ed71dd4f3d4..0403bc18ace 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -52,44 +52,15 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
         if (msg.sender == _getAdmin()) {
             bytes4 selector = msg.sig;
             if (selector == ITransparentUpgradeableProxy.admin.selector) {
-                // Returns the current admin.
-                //
-                // TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
-                // https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
-                // `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
-                _requireZeroValue();
-                address admin = _getAdmin();
-                assembly {
-                    mstore(0x00, admin)
-                    return(0, 0x20)
-                }
+                _internalAdmin();
             } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
-                // Returns the current implementation.
-                // TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
-                // https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
-                // `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
-                _requireZeroValue();
-                address implementation = _implementation();
-                assembly {
-                    mstore(0x00, implementation)
-                    return(0, 0x20)
-                }
+                _internalImplementation();
             } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
-                // Changes the admin of the proxy.
-                _requireZeroValue();
-                address newAdmin = abi.decode(msg.data[4:], (address));
-                _changeAdmin(newAdmin);
+                _internalChangeAdmin();
             } else if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
-                // Upgrade the implementation of the proxy.
-                _requireZeroValue();
-                address newImplementation = abi.decode(msg.data[4:], (address));
-                _upgradeToAndCall(newImplementation, bytes(""), false);
+                _internalUpgradeTo();
             } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
-                // Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
-                // by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
-                // proxied contract.
-                (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
-                _upgradeToAndCall(newImplementation, data, true);
+                _internalUpgradeToAndCall();
             } else {
                 revert('TransparentUpgradeableProxy: admin cannot fallback to proxy target');
             }
@@ -98,6 +69,69 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
         }
     }
 
+    /**
+     * Returns the current admin.
+     *
+     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
+     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
+     * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
+     */
+    function _internalAdmin() private {
+        _requireZeroValue();
+        address admin = _getAdmin();
+        assembly {
+            mstore(0x00, admin)
+            return(0, 0x20)
+        }
+    }
+
+    /**
+     * @dev Returns the current implementation.
+     *
+     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
+     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
+     * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
+     */
+    function _internalImplementation() private {
+        _requireZeroValue();
+
+        address implementation = _implementation();
+        assembly {
+            mstore(0x00, implementation)
+            return(0, 0x20)
+        }
+    }
+
+    /**
+     * @dev Changes the admin of the proxy.
+     */
+    function _internalChangeAdmin() private {
+        _requireZeroValue();
+
+        address newAdmin = abi.decode(msg.data[4:], (address));
+        _changeAdmin(newAdmin);
+    }
+
+    /**
+     * @dev Upgrade the implementation of the proxy.
+     */
+    function _internalUpgradeTo() private {
+        _requireZeroValue();
+
+        address newImplementation = abi.decode(msg.data[4:], (address));
+        _upgradeToAndCall(newImplementation, bytes(""), false);
+    }
+
+    /**
+     * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
+     * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
+     * proxied contract.
+     */
+    function _internalUpgradeToAndCall() private {
+        (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
+        _upgradeToAndCall(newImplementation, data, true);
+    }
+
     /**
      * @dev Returns the current admin.
      */

From d7fbc2d540cfcb39d8c2de3ff9cd43c196527780 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 23 Mar 2023 18:32:33 +0100
Subject: [PATCH 04/20] cleanup

---
 contracts/proxy/transparent/TransparentUpgradeableProxy.sol | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index 0403bc18ace..6b3005a9b35 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -70,7 +70,7 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
     }
 
     /**
-     * Returns the current admin.
+     * @dev Returns the current admin.
      *
      * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
      * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.

From a7cec2fb5acd186ef83d079d3311de61b9546f89 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 23 Mar 2023 20:00:46 +0100
Subject: [PATCH 05/20] =?UTF-8?q?rename=20=5FinternalX=20=E2=86=92=20=5Fdi?=
 =?UTF-8?q?spatchX=20&=20returns=20bytes?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../TransparentUpgradeableProxy.sol           | 41 +++++++++++--------
 1 file changed, 23 insertions(+), 18 deletions(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index 6b3005a9b35..cf6da7b08c9 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -50,20 +50,24 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
      */
     function _fallback() internal virtual override {
         if (msg.sender == _getAdmin()) {
+            bytes memory ret;
             bytes4 selector = msg.sig;
             if (selector == ITransparentUpgradeableProxy.admin.selector) {
-                _internalAdmin();
+                ret = _dispatchAdmin();
             } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
-                _internalImplementation();
+                ret = _dispatchImplementation();
             } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
-                _internalChangeAdmin();
+                ret = _dispatchChangeAdmin();
             } else if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
-                _internalUpgradeTo();
+                ret = _dispatchUpgradeTo();
             } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
-                _internalUpgradeToAndCall();
+                ret = _dispatchUpgradeToAndCall();
             } else {
                 revert('TransparentUpgradeableProxy: admin cannot fallback to proxy target');
             }
+            assembly {
+                return(add(ret, 0x20), mload(ret))
+            }
         } else {
             super._fallback();
         }
@@ -76,13 +80,11 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
      * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
      * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
      */
-    function _internalAdmin() private {
+    function _dispatchAdmin() private returns (bytes memory) {
         _requireZeroValue();
+
         address admin = _getAdmin();
-        assembly {
-            mstore(0x00, admin)
-            return(0, 0x20)
-        }
+        return abi.encode(admin);
     }
 
     /**
@@ -92,34 +94,35 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
      * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
      * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
      */
-    function _internalImplementation() private {
+    function _dispatchImplementation() private returns (bytes memory) {
         _requireZeroValue();
 
         address implementation = _implementation();
-        assembly {
-            mstore(0x00, implementation)
-            return(0, 0x20)
-        }
+        return abi.encode(implementation);
     }
 
     /**
      * @dev Changes the admin of the proxy.
      */
-    function _internalChangeAdmin() private {
+    function _dispatchChangeAdmin() private returns (bytes memory) {
         _requireZeroValue();
 
         address newAdmin = abi.decode(msg.data[4:], (address));
         _changeAdmin(newAdmin);
+
+        return "";
     }
 
     /**
      * @dev Upgrade the implementation of the proxy.
      */
-    function _internalUpgradeTo() private {
+    function _dispatchUpgradeTo() private returns (bytes memory) {
         _requireZeroValue();
 
         address newImplementation = abi.decode(msg.data[4:], (address));
         _upgradeToAndCall(newImplementation, bytes(""), false);
+
+        return "";
     }
 
     /**
@@ -127,9 +130,11 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
      * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
      * proxied contract.
      */
-    function _internalUpgradeToAndCall() private {
+    function _dispatchUpgradeToAndCall() private returns (bytes memory) {
         (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
         _upgradeToAndCall(newImplementation, data, true);
+
+        return "";
     }
 
     /**

From 6d5e72f17e0f26d8435b495e8af82750e7bbe934 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 23 Mar 2023 20:04:30 +0100
Subject: [PATCH 06/20] view functions in the interface

---
 .../TransparentUpgradeableProxy.sol           |  4 ++--
 .../TransparentUpgradeableProxy.behaviour.js  | 22 +++++++++----------
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index cf6da7b08c9..33b05eec5ad 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -8,8 +8,8 @@ import "../ERC1967/ERC1967Proxy.sol";
 interface ITransparentUpgradeableProxy {
     event Upgraded(address indexed implementation);
     event AdminChanged(address previousAdmin, address newAdmin);
-    function admin() external returns (address);
-    function implementation() external returns (address);
+    function admin() external view returns (address);
+    function implementation() external view returns (address);
     function changeAdmin(address) external;
     function upgradeTo(address) external;
     function upgradeToAndCall(address, bytes memory) payable external;
diff --git a/test/proxy/transparent/TransparentUpgradeableProxy.behaviour.js b/test/proxy/transparent/TransparentUpgradeableProxy.behaviour.js
index 3a10357a905..66c0a406cac 100644
--- a/test/proxy/transparent/TransparentUpgradeableProxy.behaviour.js
+++ b/test/proxy/transparent/TransparentUpgradeableProxy.behaviour.js
@@ -34,7 +34,7 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy(createProx
 
   describe('implementation', function () {
     it('returns the current implementation address', async function () {
-      const implementation = await this.proxy.implementation.call({ from: proxyAdminAddress });
+      const implementation = await this.proxy.implementation({ from: proxyAdminAddress });
 
       expect(implementation).to.be.equal(this.implementationV0);
     });
@@ -55,7 +55,7 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy(createProx
         it('upgrades to the requested implementation', async function () {
           await this.proxy.upgradeTo(this.implementationV1, { from });
 
-          const implementation = await this.proxy.implementation.call({ from: proxyAdminAddress });
+          const implementation = await this.proxy.implementation({ from: proxyAdminAddress });
           expect(implementation).to.be.equal(this.implementationV1);
         });
 
@@ -103,7 +103,7 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy(createProx
           });
 
           it('upgrades to the requested implementation', async function () {
-            const implementation = await this.proxy.implementation.call({ from: proxyAdminAddress });
+            const implementation = await this.proxy.implementation({ from: proxyAdminAddress });
             expect(implementation).to.be.equal(this.behavior.address);
           });
 
@@ -168,7 +168,7 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy(createProx
           });
 
           it('upgrades to the requested version and emits an event', async function () {
-            const implementation = await this.proxy.implementation.call({ from: proxyAdminAddress });
+            const implementation = await this.proxy.implementation({ from: proxyAdminAddress });
             expect(implementation).to.be.equal(this.behaviorV1.address);
             expectEvent(this.receipt, 'Upgraded', { implementation: this.behaviorV1.address });
           });
@@ -196,7 +196,7 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy(createProx
             });
 
             it('upgrades to the requested version and emits an event', async function () {
-              const implementation = await this.proxy.implementation.call({ from: proxyAdminAddress });
+              const implementation = await this.proxy.implementation({ from: proxyAdminAddress });
               expect(implementation).to.be.equal(this.behaviorV2.address);
               expectEvent(this.receipt, 'Upgraded', { implementation: this.behaviorV2.address });
             });
@@ -227,7 +227,7 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy(createProx
               });
 
               it('upgrades to the requested version and emits an event', async function () {
-                const implementation = await this.proxy.implementation.call({ from: proxyAdminAddress });
+                const implementation = await this.proxy.implementation({ from: proxyAdminAddress });
                 expect(implementation).to.be.equal(this.behaviorV3.address);
                 expectEvent(this.receipt, 'Upgraded', { implementation: this.behaviorV3.address });
               });
@@ -271,7 +271,7 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy(createProx
         });
 
         it('assigns new proxy admin', async function () {
-          const newProxyAdmin = await this.proxy.admin.call({ from: newAdmin });
+          const newProxyAdmin = await this.proxy.admin({ from: newAdmin });
           expect(newProxyAdmin).to.be.equal(anotherAccount);
         });
 
@@ -332,21 +332,21 @@ module.exports = function shouldBehaveLikeTransparentUpgradeableProxy(createProx
 
     describe('when function names clash', function () {
       it('when sender is proxy admin should run the proxy function', async function () {
-        const value = await this.proxy.admin.call({ from: proxyAdminAddress, value: 0 });
+        const value = await this.proxy.admin({ from: proxyAdminAddress, value: 0 });
         expect(value).to.be.equal(proxyAdminAddress);
       });
 
       it('when sender is other should delegate to implementation', async function () {
-        const value = await this.proxy.admin.call({ from: anotherAccount, value: 0 });
+        const value = await this.proxy.admin({ from: anotherAccount, value: 0 });
         expect(value).to.be.equal('0x0000000000000000000000000000000011111142');
       });
 
       it('when sender is proxy admin value should not be accepted', async function () {
-        await expectRevert.unspecified(this.proxy.admin.call({ from: proxyAdminAddress, value: 1 }));
+        await expectRevert.unspecified(this.proxy.admin({ from: proxyAdminAddress, value: 1 }));
       });
 
       it('when sender is other value should be accepted', async function () {
-        const value = await this.proxy.admin.call({ from: anotherAccount, value: 1 });
+        const value = await this.proxy.admin({ from: anotherAccount, value: 1 });
         expect(value).to.be.equal('0x0000000000000000000000000000000011111142');
       });
     });

From 15297153c8d93066f33940231cd2a27aff1327e1 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 23 Mar 2023 20:05:19 +0100
Subject: [PATCH 07/20] reorder dispatch for gas optimisation

---
 .../transparent/TransparentUpgradeableProxy.sol    | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index 33b05eec5ad..a6978c3e10b 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -52,16 +52,16 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
         if (msg.sender == _getAdmin()) {
             bytes memory ret;
             bytes4 selector = msg.sig;
-            if (selector == ITransparentUpgradeableProxy.admin.selector) {
-                ret = _dispatchAdmin();
-            } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
-                ret = _dispatchImplementation();
-            } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
-                ret = _dispatchChangeAdmin();
-            } else if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
+            if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
                 ret = _dispatchUpgradeTo();
             } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
                 ret = _dispatchUpgradeToAndCall();
+            } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
+                ret = _dispatchChangeAdmin();
+            } else if (selector == ITransparentUpgradeableProxy.admin.selector) {
+                ret = _dispatchAdmin();
+            } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
+                ret = _dispatchImplementation();
             } else {
                 revert('TransparentUpgradeableProxy: admin cannot fallback to proxy target');
             }

From e8a44a77d2e4a373b91b60807d028646384a10d2 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Mon, 3 Apr 2023 19:07:42 +0200
Subject: [PATCH 08/20] add changeset

---
 .changeset/thirty-shrimps-mix.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/thirty-shrimps-mix.md

diff --git a/.changeset/thirty-shrimps-mix.md b/.changeset/thirty-shrimps-mix.md
new file mode 100644
index 00000000000..cd3cc01ba24
--- /dev/null
+++ b/.changeset/thirty-shrimps-mix.md
@@ -0,0 +1,5 @@
+---
+'openzeppelin-solidity': patch
+---
+
+`TransparentUpgradeableProxy`: fix transparency in case of selector clash with non-decodable calldata

From 5a1df2c8a6ae9831d6825eb4060738b97ac1a7b6 Mon Sep 17 00:00:00 2001
From: Francisco <fg@frang.io>
Date: Mon, 3 Apr 2023 17:15:05 -0300
Subject: [PATCH 09/20] typo

---
 contracts/proxy/transparent/TransparentUpgradeableProxy.sol | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index a6978c3e10b..cec67536f1d 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -46,7 +46,7 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
     }
 
     /**
-     * @dev If caller is the admin process the call internally, otherwize transparently fallback to the proxy behavior
+     * @dev If caller is the admin process the call internally, otherwise transparently fallback to the proxy behavior
      */
     function _fallback() internal virtual override {
         if (msg.sender == _getAdmin()) {

From f6f8a48077eaf398f1cc2d4d4024a4685cd1b944 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Tue, 4 Apr 2023 14:26:20 +0200
Subject: [PATCH 10/20] add IERC1967 & reenable ifAdmin modifier

---
 contracts/interfaces/IERC1967.sol             | 20 ++++++++++++++++
 contracts/proxy/ERC1967/ERC1967Upgrade.sol    | 13 ++--------
 .../TransparentUpgradeableProxy.sol           | 24 ++++++++++++++++---
 3 files changed, 43 insertions(+), 14 deletions(-)
 create mode 100644 contracts/interfaces/IERC1967.sol

diff --git a/contracts/interfaces/IERC1967.sol b/contracts/interfaces/IERC1967.sol
new file mode 100644
index 00000000000..9181e59daad
--- /dev/null
+++ b/contracts/interfaces/IERC1967.sol
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+/**
+ * @dev ERC-1967: Proxy Storage Slots.
+ *
+ * _Available since v4.9._
+ */
+interface IERC1967 {
+    /**
+     * @dev Emitted when the implementation is upgraded.
+     */
+    event Upgraded(address indexed implementation);
+
+    /**
+     * @dev Emitted when the admin account has changed.
+     */
+    event AdminChanged(address previousAdmin, address newAdmin);
+}
\ No newline at end of file
diff --git a/contracts/proxy/ERC1967/ERC1967Upgrade.sol b/contracts/proxy/ERC1967/ERC1967Upgrade.sol
index 0680f35499b..be6929e8162 100644
--- a/contracts/proxy/ERC1967/ERC1967Upgrade.sol
+++ b/contracts/proxy/ERC1967/ERC1967Upgrade.sol
@@ -4,6 +4,7 @@
 pragma solidity ^0.8.2;
 
 import "../beacon/IBeacon.sol";
+import "../../interfaces/IERC1967.sol";
 import "../../interfaces/draft-IERC1822.sol";
 import "../../utils/Address.sol";
 import "../../utils/StorageSlot.sol";
@@ -14,7 +15,7 @@ import "../../utils/StorageSlot.sol";
  *
  * _Available since v4.1._
  */
-abstract contract ERC1967Upgrade {
+abstract contract ERC1967Upgrade is IERC1967 {
     // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
     bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
 
@@ -25,11 +26,6 @@ abstract contract ERC1967Upgrade {
      */
     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 
-    /**
-     * @dev Emitted when the implementation is upgraded.
-     */
-    event Upgraded(address indexed implementation);
-
     /**
      * @dev Returns the current implementation address.
      */
@@ -95,11 +91,6 @@ abstract contract ERC1967Upgrade {
      */
     bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
 
-    /**
-     * @dev Emitted when the admin account has changed.
-     */
-    event AdminChanged(address previousAdmin, address newAdmin);
-
     /**
      * @dev Returns the current admin.
      */
diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index a6978c3e10b..2472e5994f4 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -5,9 +5,13 @@ pragma solidity ^0.8.0;
 
 import "../ERC1967/ERC1967Proxy.sol";
 
-interface ITransparentUpgradeableProxy {
-    event Upgraded(address indexed implementation);
-    event AdminChanged(address previousAdmin, address newAdmin);
+/**
+ * @dev Interface for the {TransparentUpgradeableProxy}. This is usefull because {TransparentUpgradeableProxy} uses a
+ * custom call-routing mechanism, the compiler is unaware of the functions being exposed, and cannot list them. Also
+ * {TransparentUpgradeableProxy} does not inherit from this interface because its implemented in a way that the
+ * compiler doesn't understand and cannot verify.
+ */
+interface ITransparentUpgradeableProxy is IERC1967 {
     function admin() external view returns (address);
     function implementation() external view returns (address);
     function changeAdmin(address) external;
@@ -45,6 +49,20 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
         _changeAdmin(admin_);
     }
 
+    /**
+     * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
+     *
+     * CAUTION: this modifier is deprecated, as it could cause issues if the modified function as arguments, and the
+     * implementation provide a function with a similar selector.
+     */
+    modifier ifAdmin() {
+        if (msg.sender == _getAdmin()) {
+            _;
+        } else {
+            _fallback();
+        }
+    }
+
     /**
      * @dev If caller is the admin process the call internally, otherwize transparently fallback to the proxy behavior
      */

From 4583b59e2e9e05ed5a62440920efc7cf0ae790fc Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Tue, 4 Apr 2023 14:35:51 +0200
Subject: [PATCH 11/20] spelling

---
 contracts/proxy/transparent/TransparentUpgradeableProxy.sol | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index 2e724b52271..1aaf3808c62 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -6,7 +6,7 @@ pragma solidity ^0.8.0;
 import "../ERC1967/ERC1967Proxy.sol";
 
 /**
- * @dev Interface for the {TransparentUpgradeableProxy}. This is usefull because {TransparentUpgradeableProxy} uses a
+ * @dev Interface for the {TransparentUpgradeableProxy}. This is useful because {TransparentUpgradeableProxy} uses a
  * custom call-routing mechanism, the compiler is unaware of the functions being exposed, and cannot list them. Also
  * {TransparentUpgradeableProxy} does not inherit from this interface because its implemented in a way that the
  * compiler doesn't understand and cannot verify.

From 9041109412563f4e37e06e3d843f6239ffe54d94 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Tue, 4 Apr 2023 14:48:43 +0200
Subject: [PATCH 12/20] Update IERC1967.sol

---
 contracts/interfaces/IERC1967.sol | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/contracts/interfaces/IERC1967.sol b/contracts/interfaces/IERC1967.sol
index 9181e59daad..6070bd43970 100644
--- a/contracts/interfaces/IERC1967.sol
+++ b/contracts/interfaces/IERC1967.sol
@@ -17,4 +17,4 @@ interface IERC1967 {
      * @dev Emitted when the admin account has changed.
      */
     event AdminChanged(address previousAdmin, address newAdmin);
-}
\ No newline at end of file
+}

From 0b144e66b5b26b766c75f7420dd123e76c6f8976 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Tue, 4 Apr 2023 14:50:44 +0200
Subject: [PATCH 13/20] re-add comment

---
 contracts/proxy/transparent/TransparentUpgradeableProxy.sol | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index 1aaf3808c62..f51a374c024 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -121,6 +121,8 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
 
     /**
      * @dev Changes the admin of the proxy.
+     *
+     * Emits an {AdminChanged} event.
      */
     function _dispatchChangeAdmin() private returns (bytes memory) {
         _requireZeroValue();

From 707cde88ee410e62a0eb4a9a284105e4ba7b04e4 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Tue, 4 Apr 2023 17:09:11 +0200
Subject: [PATCH 14/20] add a warning about missing ABI and possible selector
 clash in TransparentUpgradeableProxy

---
 .../proxy/transparent/TransparentUpgradeableProxy.sol      | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index f51a374c024..9a8abf3537a 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -39,6 +39,13 @@ interface ITransparentUpgradeableProxy is IERC1967 {
  *
  * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
  * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
+ *
+ * WARNING: this contract does not inherit from {ITransparentUpgradeableProxy}, and the admin function implicitly
+ * implemented using a custom call-routing mechanism in `_fallback`. Consequently, the compiler will not produce an
+ * ABI for this contract. Also, if you inherit from this contract and add additional functions, the compiler will not
+ * check that there are no selector conflicts. Selector clash between any new function and the functions declared in
+ * {ITransparentUpgradeableProxy} will be resolved in favor of the new one. This could render the admin operation
+ * inaccessible, with could prevent upgradeability.
  */
 contract TransparentUpgradeableProxy is ERC1967Proxy {
     /**

From 7750b9cde35b0a1fe6fc15d08bc4bb3473b9dc73 Mon Sep 17 00:00:00 2001
From: Francisco <fg@frang.io>
Date: Tue, 4 Apr 2023 12:49:14 -0300
Subject: [PATCH 15/20] grammar

---
 .../proxy/transparent/TransparentUpgradeableProxy.sol     | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index 9a8abf3537a..3fbf1895cdb 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -40,12 +40,12 @@ interface ITransparentUpgradeableProxy is IERC1967 {
  * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
  * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
  *
- * WARNING: this contract does not inherit from {ITransparentUpgradeableProxy}, and the admin function implicitly
+ * WARNING: This contract does not inherit from {ITransparentUpgradeableProxy}, and the admin function is implicitly
  * implemented using a custom call-routing mechanism in `_fallback`. Consequently, the compiler will not produce an
  * ABI for this contract. Also, if you inherit from this contract and add additional functions, the compiler will not
- * check that there are no selector conflicts. Selector clash between any new function and the functions declared in
- * {ITransparentUpgradeableProxy} will be resolved in favor of the new one. This could render the admin operation
- * inaccessible, with could prevent upgradeability.
+ * check that there are no selector conflicts. A selector clash between any new function and the functions declared in
+ * {ITransparentUpgradeableProxy} will be resolved in favor of the new one. This could render the admin operations
+ * inaccessible, which could prevent upgradeability.
  */
 contract TransparentUpgradeableProxy is ERC1967Proxy {
     /**

From de042ada9ddbc6bbf57a1fded11ff8e955eb0efa Mon Sep 17 00:00:00 2001
From: Francisco <fg@frang.io>
Date: Tue, 4 Apr 2023 13:15:16 -0300
Subject: [PATCH 16/20] grammar

---
 contracts/proxy/transparent/TransparentUpgradeableProxy.sol | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index 3fbf1895cdb..eae79c508e0 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -59,8 +59,8 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
     /**
      * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
      *
-     * CAUTION: this modifier is deprecated, as it could cause issues if the modified function as arguments, and the
-     * implementation provide a function with a similar selector.
+     * CAUTION: This modifier is deprecated, as it could cause issues if the modified function has arguments, and the
+     * implementation provides a function with the same selector.
      */
     modifier ifAdmin() {
         if (msg.sender == _getAdmin()) {

From 5a029ce32664cd99b0f2dfde4cf7088001e956de Mon Sep 17 00:00:00 2001
From: Francisco Giordano <fg@frang.io>
Date: Tue, 4 Apr 2023 13:53:15 -0300
Subject: [PATCH 17/20] fix ProxyAdmin test

---
 test/proxy/transparent/ProxyAdmin.test.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/test/proxy/transparent/ProxyAdmin.test.js b/test/proxy/transparent/ProxyAdmin.test.js
index 811dc5671f0..6d473d89379 100644
--- a/test/proxy/transparent/ProxyAdmin.test.js
+++ b/test/proxy/transparent/ProxyAdmin.test.js
@@ -6,6 +6,7 @@ const ImplV1 = artifacts.require('DummyImplementation');
 const ImplV2 = artifacts.require('DummyImplementationV2');
 const ProxyAdmin = artifacts.require('ProxyAdmin');
 const TransparentUpgradeableProxy = artifacts.require('TransparentUpgradeableProxy');
+const ITransparentUpgradeableProxy = artifacts.require('ITransparentUpgradeableProxy');
 
 contract('ProxyAdmin', function (accounts) {
   const [proxyAdminOwner, newAdmin, anotherAccount] = accounts;
@@ -18,12 +19,13 @@ contract('ProxyAdmin', function (accounts) {
   beforeEach(async function () {
     const initializeData = Buffer.from('');
     this.proxyAdmin = await ProxyAdmin.new({ from: proxyAdminOwner });
-    this.proxy = await TransparentUpgradeableProxy.new(
+    const proxy = await TransparentUpgradeableProxy.new(
       this.implementationV1.address,
       this.proxyAdmin.address,
       initializeData,
       { from: proxyAdminOwner },
     );
+    this.proxy = await ITransparentUpgradeableProxy.at(proxy.address);
   });
 
   it('has an owner', async function () {

From f7595a69af61af20e125dbe5861a6c3b849a1903 Mon Sep 17 00:00:00 2001
From: Francisco Giordano <fg@frang.io>
Date: Tue, 4 Apr 2023 13:54:52 -0300
Subject: [PATCH 18/20] lint

---
 .../proxy/transparent/TransparentUpgradeableProxy.sol     | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index eae79c508e0..651f74448a9 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -13,10 +13,14 @@ import "../ERC1967/ERC1967Proxy.sol";
  */
 interface ITransparentUpgradeableProxy is IERC1967 {
     function admin() external view returns (address);
+
     function implementation() external view returns (address);
+
     function changeAdmin(address) external;
+
     function upgradeTo(address) external;
-    function upgradeToAndCall(address, bytes memory) payable external;
+
+    function upgradeToAndCall(address, bytes memory) external payable;
 }
 
 /**
@@ -88,7 +92,7 @@ contract TransparentUpgradeableProxy is ERC1967Proxy {
             } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
                 ret = _dispatchImplementation();
             } else {
-                revert('TransparentUpgradeableProxy: admin cannot fallback to proxy target');
+                revert("TransparentUpgradeableProxy: admin cannot fallback to proxy target");
             }
             assembly {
                 return(add(ret, 0x20), mload(ret))

From 4b61bfe653167d7a1ba076c1645b7c1ffc7fc324 Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Wed, 5 Apr 2023 10:30:26 +0200
Subject: [PATCH 19/20] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Ernesto García <ernestognw@gmail.com>
Co-authored-by: Francisco <fg@frang.io>
---
 .changeset/thirty-shrimps-mix.md                           | 2 +-
 contracts/interfaces/IERC1967.sol                          | 7 ++++++-
 .../proxy/transparent/TransparentUpgradeableProxy.sol      | 2 +-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/.changeset/thirty-shrimps-mix.md b/.changeset/thirty-shrimps-mix.md
index cd3cc01ba24..54256d52cbf 100644
--- a/.changeset/thirty-shrimps-mix.md
+++ b/.changeset/thirty-shrimps-mix.md
@@ -2,4 +2,4 @@
 'openzeppelin-solidity': patch
 ---
 
-`TransparentUpgradeableProxy`: fix transparency in case of selector clash with non-decodable calldata
+`TransparentUpgradeableProxy`: Fix transparency in case of selector clash with non-decodable calldata.
diff --git a/contracts/interfaces/IERC1967.sol b/contracts/interfaces/IERC1967.sol
index 6070bd43970..e5deebee9c2 100644
--- a/contracts/interfaces/IERC1967.sol
+++ b/contracts/interfaces/IERC1967.sol
@@ -3,7 +3,7 @@
 pragma solidity ^0.8.0;
 
 /**
- * @dev ERC-1967: Proxy Storage Slots.
+ * @dev ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC.
  *
  * _Available since v4.9._
  */
@@ -17,4 +17,9 @@ interface IERC1967 {
      * @dev Emitted when the admin account has changed.
      */
     event AdminChanged(address previousAdmin, address newAdmin);
+
+    /**
+     * @dev Emitted when the beacon is changed.
+     */
+    event BeaconUpgraded(address indexed beacon);
 }
diff --git a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
index 651f74448a9..a89b233f235 100644
--- a/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
+++ b/contracts/proxy/transparent/TransparentUpgradeableProxy.sol
@@ -8,7 +8,7 @@ import "../ERC1967/ERC1967Proxy.sol";
 /**
  * @dev Interface for the {TransparentUpgradeableProxy}. This is useful because {TransparentUpgradeableProxy} uses a
  * custom call-routing mechanism, the compiler is unaware of the functions being exposed, and cannot list them. Also
- * {TransparentUpgradeableProxy} does not inherit from this interface because its implemented in a way that the
+ * {TransparentUpgradeableProxy} does not inherit from this interface because it's implemented in a way that the
  * compiler doesn't understand and cannot verify.
  */
 interface ITransparentUpgradeableProxy is IERC1967 {

From b082da8228dfcc42665fb4d609efb1ef0b87370f Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Wed, 5 Apr 2023 10:31:12 +0200
Subject: [PATCH 20/20] Update ERC1967Upgrade.sol

---
 contracts/proxy/ERC1967/ERC1967Upgrade.sol | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/contracts/proxy/ERC1967/ERC1967Upgrade.sol b/contracts/proxy/ERC1967/ERC1967Upgrade.sol
index be6929e8162..a79c10502c0 100644
--- a/contracts/proxy/ERC1967/ERC1967Upgrade.sol
+++ b/contracts/proxy/ERC1967/ERC1967Upgrade.sol
@@ -122,11 +122,6 @@ abstract contract ERC1967Upgrade is IERC1967 {
      */
     bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
 
-    /**
-     * @dev Emitted when the beacon is upgraded.
-     */
-    event BeaconUpgraded(address indexed beacon);
-
     /**
      * @dev Returns the current beacon.
      */