From 3bdd3ecd7b585e6bdde011c2c457a62a739e8b51 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Tue, 14 Dec 2021 16:12:42 -0500
Subject: [PATCH 01/19] Add a data parameter to the _countVote interface

---
 contracts/governance/Governor.sol             | 44 ++++++++++++++++---
 contracts/governance/IGovernor.sol            | 23 ++++++++++
 .../GovernorCompatibilityBravo.sol            |  5 ++-
 .../extensions/GovernorCountingSimple.sol     |  4 +-
 .../extensions/GovernorPreventLateQuorum.sol  |  5 ++-
 .../mocks/GovernorPreventLateQuorumMock.sol   |  5 ++-
 test/governance/Governor.test.js              |  1 +
 .../GovernorTimelockCompound.test.js          |  1 +
 .../GovernorTimelockControl.test.js           |  1 +
 .../SupportsInterface.behavior.js             | 21 +++++++++
 10 files changed, 97 insertions(+), 13 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 0da3f11706a..65c12126702 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -86,7 +86,11 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
      * @dev See {IERC165-supportsInterface}.
      */
     function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC165) returns (bool) {
-        return interfaceId == type(IGovernor).interfaceId || super.supportsInterface(interfaceId);
+        // In addition to the current interfaceId, also support previous version of the interfaceId that did not
+        // include the castVoteWithData() and castVoteWithReasonAndData() functions as standard
+        return interfaceId == (type(IGovernor).interfaceId ^ this.castVoteWithReasonAndData.selector ^ this.castVoteWithData.selector)
+            || interfaceId == type(IGovernor).interfaceId
+            || super.supportsInterface(interfaceId);
     }
 
     /**
@@ -202,7 +206,8 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         uint256 proposalId,
         address account,
         uint8 support,
-        uint256 weight
+        uint256 weight,
+        bytes memory data
     ) internal virtual;
 
     /**
@@ -360,7 +365,19 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
      */
     function castVote(uint256 proposalId, uint8 support) public virtual override returns (uint256) {
         address voter = _msgSender();
-        return _castVote(proposalId, voter, support, "");
+        return _castVote(proposalId, voter, support, "", "");
+    }
+
+    /**
+     * @dev See {IGovernor-castVoteWithData}.
+     */
+    function castVoteWithData(
+        uint256 proposalId,
+        uint8 support,
+        bytes memory data
+    ) public virtual override returns (uint256) {
+        address voter = _msgSender();
+        return _castVote(proposalId, voter, support, "", data);
     }
 
     /**
@@ -370,9 +387,21 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         uint256 proposalId,
         uint8 support,
         string calldata reason
+    ) public virtual override returns (uint256) {
+        return castVoteWithReasonAndData(proposalId, support, reason, "");
+    }
+
+    /**
+     * @dev See {IGovernor-castVoteWithReasonAndData}.
+     */
+    function castVoteWithReasonAndData(
+        uint256 proposalId,
+        uint8 support,
+        string calldata reason,
+        bytes memory data
     ) public virtual override returns (uint256) {
         address voter = _msgSender();
-        return _castVote(proposalId, voter, support, reason);
+        return _castVote(proposalId, voter, support, reason, data);
     }
 
     /**
@@ -391,7 +420,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
             r,
             s
         );
-        return _castVote(proposalId, voter, support, "");
+        return _castVote(proposalId, voter, support, "", "");
     }
 
     /**
@@ -404,13 +433,14 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         uint256 proposalId,
         address account,
         uint8 support,
-        string memory reason
+        string memory reason,
+        bytes memory data
     ) internal virtual returns (uint256) {
         ProposalCore storage proposal = _proposals[proposalId];
         require(state(proposalId) == ProposalState.Active, "Governor: vote not currently active");
 
         uint256 weight = getVotes(account, proposal.voteStart.getDeadline());
-        _countVote(proposalId, account, support, weight);
+        _countVote(proposalId, account, support, weight, data);
 
         emit VoteCast(account, proposalId, support, weight, reason);
 
diff --git a/contracts/governance/IGovernor.sol b/contracts/governance/IGovernor.sol
index 3c65f40daae..7d0c22ca1cf 100644
--- a/contracts/governance/IGovernor.sol
+++ b/contracts/governance/IGovernor.sol
@@ -192,6 +192,17 @@ abstract contract IGovernor is IERC165 {
      */
     function castVote(uint256 proposalId, uint8 support) public virtual returns (uint256 balance);
 
+    /**
+     * @dev Cast a vote with contextual data
+     *
+     * Emits a {VoteCast} event.
+     */
+    function castVoteWithData(
+        uint256 proposalId,
+        uint8 support,
+        bytes memory data
+    ) public virtual returns (uint256 balance);
+
     /**
      * @dev Cast a vote with a reason
      *
@@ -203,6 +214,18 @@ abstract contract IGovernor is IERC165 {
         string calldata reason
     ) public virtual returns (uint256 balance);
 
+    /**
+     * @dev Cast a vote with a reason and contextual data
+     *
+     * Emits a {VoteCast} event.
+     */
+    function castVoteWithReasonAndData(
+        uint256 proposalId,
+        uint8 support,
+        string calldata reason,
+        bytes memory data
+    ) public virtual returns (uint256 balance);
+
     /**
      * @dev Cast a vote using the user cryptographic signature.
      *
diff --git a/contracts/governance/compatibility/GovernorCompatibilityBravo.sol b/contracts/governance/compatibility/GovernorCompatibilityBravo.sol
index cbb2200b5f6..513c68b6913 100644
--- a/contracts/governance/compatibility/GovernorCompatibilityBravo.sol
+++ b/contracts/governance/compatibility/GovernorCompatibilityBravo.sol
@@ -265,8 +265,11 @@ abstract contract GovernorCompatibilityBravo is IGovernorTimelock, IGovernorComp
         uint256 proposalId,
         address account,
         uint8 support,
-        uint256 weight
+        uint256 weight,
+        bytes memory data
     ) internal virtual override {
+        (data); // silence compiler warnings
+
         ProposalDetails storage details = _proposalDetails[proposalId];
         Receipt storage receipt = details.receipts[account];
 
diff --git a/contracts/governance/extensions/GovernorCountingSimple.sol b/contracts/governance/extensions/GovernorCountingSimple.sol
index 38054d91789..9e106cad249 100644
--- a/contracts/governance/extensions/GovernorCountingSimple.sol
+++ b/contracts/governance/extensions/GovernorCountingSimple.sol
@@ -86,8 +86,10 @@ abstract contract GovernorCountingSimple is Governor {
         uint256 proposalId,
         address account,
         uint8 support,
-        uint256 weight
+        uint256 weight,
+        bytes memory data
     ) internal virtual override {
+        (data); // silence compiler warnings
         ProposalVote storage proposalvote = _proposalVotes[proposalId];
 
         require(!proposalvote.hasVoted[account], "GovernorVotingSimple: vote already cast");
diff --git a/contracts/governance/extensions/GovernorPreventLateQuorum.sol b/contracts/governance/extensions/GovernorPreventLateQuorum.sol
index 6d96dc33d26..3ecd8dc61aa 100644
--- a/contracts/governance/extensions/GovernorPreventLateQuorum.sol
+++ b/contracts/governance/extensions/GovernorPreventLateQuorum.sol
@@ -57,9 +57,10 @@ abstract contract GovernorPreventLateQuorum is Governor {
         uint256 proposalId,
         address account,
         uint8 support,
-        string memory reason
+        string memory reason,
+        bytes memory data
     ) internal virtual override returns (uint256) {
-        uint256 result = super._castVote(proposalId, account, support, reason);
+        uint256 result = super._castVote(proposalId, account, support, reason, data);
 
         Timers.BlockNumber storage extendedDeadline = _extendedDeadlines[proposalId];
 
diff --git a/contracts/mocks/GovernorPreventLateQuorumMock.sol b/contracts/mocks/GovernorPreventLateQuorumMock.sol
index 7de50a01f94..ea192f90ff5 100644
--- a/contracts/mocks/GovernorPreventLateQuorumMock.sol
+++ b/contracts/mocks/GovernorPreventLateQuorumMock.sol
@@ -53,8 +53,9 @@ contract GovernorPreventLateQuorumMock is
         uint256 proposalId,
         address account,
         uint8 support,
-        string memory reason
+        string memory reason,
+        bytes memory data
     ) internal virtual override(Governor, GovernorPreventLateQuorum) returns (uint256) {
-        return super._castVote(proposalId, account, support, reason);
+        return super._castVote(proposalId, account, support, reason, data);
     }
 }
diff --git a/test/governance/Governor.test.js b/test/governance/Governor.test.js
index 6017db0507b..290e0bf6944 100644
--- a/test/governance/Governor.test.js
+++ b/test/governance/Governor.test.js
@@ -41,6 +41,7 @@ contract('Governor', function (accounts) {
   shouldSupportInterfaces([
     'ERC165',
     'Governor',
+    'GovernorWithData',
   ]);
 
   it('deployment check', async function () {
diff --git a/test/governance/extensions/GovernorTimelockCompound.test.js b/test/governance/extensions/GovernorTimelockCompound.test.js
index bc4f15c99b5..3f566296bab 100644
--- a/test/governance/extensions/GovernorTimelockCompound.test.js
+++ b/test/governance/extensions/GovernorTimelockCompound.test.js
@@ -48,6 +48,7 @@ contract('GovernorTimelockCompound', function (accounts) {
   shouldSupportInterfaces([
     'ERC165',
     'Governor',
+    'GovernorWithData',
     'GovernorTimelock',
   ]);
 
diff --git a/test/governance/extensions/GovernorTimelockControl.test.js b/test/governance/extensions/GovernorTimelockControl.test.js
index 9efeb463518..9604504d205 100644
--- a/test/governance/extensions/GovernorTimelockControl.test.js
+++ b/test/governance/extensions/GovernorTimelockControl.test.js
@@ -43,6 +43,7 @@ contract('GovernorTimelockControl', function (accounts) {
   shouldSupportInterfaces([
     'ERC165',
     'Governor',
+    'GovernorWithData',
     'GovernorTimelock',
   ]);
 
diff --git a/test/utils/introspection/SupportsInterface.behavior.js b/test/utils/introspection/SupportsInterface.behavior.js
index 4f29f0e00d9..1915a9a2946 100644
--- a/test/utils/introspection/SupportsInterface.behavior.js
+++ b/test/utils/introspection/SupportsInterface.behavior.js
@@ -69,6 +69,27 @@ const INTERFACES = {
     'castVoteWithReason(uint256,uint8,string)',
     'castVoteBySig(uint256,uint8,uint8,bytes32,bytes32)',
   ],
+  GovernorWithData: [
+    'name()',
+    'version()',
+    'COUNTING_MODE()',
+    'hashProposal(address[],uint256[],bytes[],bytes32)',
+    'state(uint256)',
+    'proposalSnapshot(uint256)',
+    'proposalDeadline(uint256)',
+    'votingDelay()',
+    'votingPeriod()',
+    'quorum(uint256)',
+    'getVotes(address,uint256)',
+    'hasVoted(uint256,address)',
+    'propose(address[],uint256[],bytes[],string)',
+    'execute(address[],uint256[],bytes[],bytes32)',
+    'castVote(uint256,uint8)',
+    'castVoteWithData(uint256,uint8,bytes)',
+    'castVoteWithReason(uint256,uint8,string)',
+    'castVoteWithReasonAndData(uint256,uint8,string,bytes)',
+    'castVoteBySig(uint256,uint8,uint8,bytes32,bytes32)',
+  ],
   GovernorTimelock: [
     'timelock()',
     'proposalEta(uint256)',

From b86cbc8ad880d23efeaa8dfbcbf98bc313b22498 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Tue, 21 Dec 2021 16:45:26 -0500
Subject: [PATCH 02/19] linter fix

---
 contracts/governance/Governor.sol | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 65c12126702..62600855204 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -88,9 +88,11 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
     function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC165) returns (bool) {
         // In addition to the current interfaceId, also support previous version of the interfaceId that did not
         // include the castVoteWithData() and castVoteWithReasonAndData() functions as standard
-        return interfaceId == (type(IGovernor).interfaceId ^ this.castVoteWithReasonAndData.selector ^ this.castVoteWithData.selector)
-            || interfaceId == type(IGovernor).interfaceId
-            || super.supportsInterface(interfaceId);
+        return
+            interfaceId ==
+            (type(IGovernor).interfaceId ^ this.castVoteWithReasonAndData.selector ^ this.castVoteWithData.selector) ||
+            interfaceId == type(IGovernor).interfaceId ||
+            super.supportsInterface(interfaceId);
     }
 
     /**

From 6aaad8483384312b91d73ce68e0540fe278c5e40 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Tue, 21 Dec 2021 18:00:58 -0500
Subject: [PATCH 03/19] Rename governor extension data extension to params

---
 contracts/governance/Governor.sol             | 28 +++++++++----------
 contracts/governance/IGovernor.sol            | 12 ++++----
 .../GovernorCompatibilityBravo.sol            |  4 +--
 .../extensions/GovernorCountingSimple.sol     |  4 +--
 .../extensions/GovernorPreventLateQuorum.sol  |  4 +--
 .../mocks/GovernorPreventLateQuorumMock.sol   |  4 +--
 test/governance/Governor.test.js              |  2 +-
 .../GovernorTimelockCompound.test.js          |  2 +-
 .../GovernorTimelockControl.test.js           |  2 +-
 .../SupportsInterface.behavior.js             |  6 ++--
 10 files changed, 34 insertions(+), 34 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 62600855204..9a7b2d8ecc0 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -87,10 +87,10 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
      */
     function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC165) returns (bool) {
         // In addition to the current interfaceId, also support previous version of the interfaceId that did not
-        // include the castVoteWithData() and castVoteWithReasonAndData() functions as standard
+        // include the castVoteWithParams() and castVoteWithReasonAndParams() functions as standard
         return
             interfaceId ==
-            (type(IGovernor).interfaceId ^ this.castVoteWithReasonAndData.selector ^ this.castVoteWithData.selector) ||
+            (type(IGovernor).interfaceId ^ this.castVoteWithReasonAndParams.selector ^ this.castVoteWithParams.selector) ||
             interfaceId == type(IGovernor).interfaceId ||
             super.supportsInterface(interfaceId);
     }
@@ -209,7 +209,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         address account,
         uint8 support,
         uint256 weight,
-        bytes memory data
+        bytes memory params
     ) internal virtual;
 
     /**
@@ -371,15 +371,15 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
     }
 
     /**
-     * @dev See {IGovernor-castVoteWithData}.
+     * @dev See {IGovernor-castVoteWithParams}.
      */
-    function castVoteWithData(
+    function castVoteWithParams(
         uint256 proposalId,
         uint8 support,
-        bytes memory data
+        bytes memory params
     ) public virtual override returns (uint256) {
         address voter = _msgSender();
-        return _castVote(proposalId, voter, support, "", data);
+        return _castVote(proposalId, voter, support, "", params);
     }
 
     /**
@@ -390,20 +390,20 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         uint8 support,
         string calldata reason
     ) public virtual override returns (uint256) {
-        return castVoteWithReasonAndData(proposalId, support, reason, "");
+        return castVoteWithReasonAndParams(proposalId, support, reason, "");
     }
 
     /**
-     * @dev See {IGovernor-castVoteWithReasonAndData}.
+     * @dev See {IGovernor-castVoteWithReasonAndParams}.
      */
-    function castVoteWithReasonAndData(
+    function castVoteWithReasonAndParams(
         uint256 proposalId,
         uint8 support,
         string calldata reason,
-        bytes memory data
+        bytes memory params
     ) public virtual override returns (uint256) {
         address voter = _msgSender();
-        return _castVote(proposalId, voter, support, reason, data);
+        return _castVote(proposalId, voter, support, reason, params);
     }
 
     /**
@@ -436,13 +436,13 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         address account,
         uint8 support,
         string memory reason,
-        bytes memory data
+        bytes memory params
     ) internal virtual returns (uint256) {
         ProposalCore storage proposal = _proposals[proposalId];
         require(state(proposalId) == ProposalState.Active, "Governor: vote not currently active");
 
         uint256 weight = getVotes(account, proposal.voteStart.getDeadline());
-        _countVote(proposalId, account, support, weight, data);
+        _countVote(proposalId, account, support, weight, params);
 
         emit VoteCast(account, proposalId, support, weight, reason);
 
diff --git a/contracts/governance/IGovernor.sol b/contracts/governance/IGovernor.sol
index 7d0c22ca1cf..32777d5831a 100644
--- a/contracts/governance/IGovernor.sol
+++ b/contracts/governance/IGovernor.sol
@@ -193,14 +193,14 @@ abstract contract IGovernor is IERC165 {
     function castVote(uint256 proposalId, uint8 support) public virtual returns (uint256 balance);
 
     /**
-     * @dev Cast a vote with contextual data
+     * @dev Cast a vote with additional encoded parameters
      *
      * Emits a {VoteCast} event.
      */
-    function castVoteWithData(
+    function castVoteWithParams(
         uint256 proposalId,
         uint8 support,
-        bytes memory data
+        bytes memory params
     ) public virtual returns (uint256 balance);
 
     /**
@@ -215,15 +215,15 @@ abstract contract IGovernor is IERC165 {
     ) public virtual returns (uint256 balance);
 
     /**
-     * @dev Cast a vote with a reason and contextual data
+     * @dev Cast a vote with a reason and additional encoded parameters
      *
      * Emits a {VoteCast} event.
      */
-    function castVoteWithReasonAndData(
+    function castVoteWithReasonAndParams(
         uint256 proposalId,
         uint8 support,
         string calldata reason,
-        bytes memory data
+        bytes memory params
     ) public virtual returns (uint256 balance);
 
     /**
diff --git a/contracts/governance/compatibility/GovernorCompatibilityBravo.sol b/contracts/governance/compatibility/GovernorCompatibilityBravo.sol
index 513c68b6913..5648744463d 100644
--- a/contracts/governance/compatibility/GovernorCompatibilityBravo.sol
+++ b/contracts/governance/compatibility/GovernorCompatibilityBravo.sol
@@ -266,9 +266,9 @@ abstract contract GovernorCompatibilityBravo is IGovernorTimelock, IGovernorComp
         address account,
         uint8 support,
         uint256 weight,
-        bytes memory data
+        bytes memory params
     ) internal virtual override {
-        (data); // silence compiler warnings
+        (params); // silence compiler warnings
 
         ProposalDetails storage details = _proposalDetails[proposalId];
         Receipt storage receipt = details.receipts[account];
diff --git a/contracts/governance/extensions/GovernorCountingSimple.sol b/contracts/governance/extensions/GovernorCountingSimple.sol
index 9e106cad249..117ae3953e9 100644
--- a/contracts/governance/extensions/GovernorCountingSimple.sol
+++ b/contracts/governance/extensions/GovernorCountingSimple.sol
@@ -87,9 +87,9 @@ abstract contract GovernorCountingSimple is Governor {
         address account,
         uint8 support,
         uint256 weight,
-        bytes memory data
+        bytes memory params
     ) internal virtual override {
-        (data); // silence compiler warnings
+        (params); // silence compiler warnings
         ProposalVote storage proposalvote = _proposalVotes[proposalId];
 
         require(!proposalvote.hasVoted[account], "GovernorVotingSimple: vote already cast");
diff --git a/contracts/governance/extensions/GovernorPreventLateQuorum.sol b/contracts/governance/extensions/GovernorPreventLateQuorum.sol
index 3ecd8dc61aa..5b58f6032bf 100644
--- a/contracts/governance/extensions/GovernorPreventLateQuorum.sol
+++ b/contracts/governance/extensions/GovernorPreventLateQuorum.sol
@@ -58,9 +58,9 @@ abstract contract GovernorPreventLateQuorum is Governor {
         address account,
         uint8 support,
         string memory reason,
-        bytes memory data
+        bytes memory params
     ) internal virtual override returns (uint256) {
-        uint256 result = super._castVote(proposalId, account, support, reason, data);
+        uint256 result = super._castVote(proposalId, account, support, reason, params);
 
         Timers.BlockNumber storage extendedDeadline = _extendedDeadlines[proposalId];
 
diff --git a/contracts/mocks/GovernorPreventLateQuorumMock.sol b/contracts/mocks/GovernorPreventLateQuorumMock.sol
index ea192f90ff5..35bddc03b42 100644
--- a/contracts/mocks/GovernorPreventLateQuorumMock.sol
+++ b/contracts/mocks/GovernorPreventLateQuorumMock.sol
@@ -54,8 +54,8 @@ contract GovernorPreventLateQuorumMock is
         address account,
         uint8 support,
         string memory reason,
-        bytes memory data
+        bytes memory params
     ) internal virtual override(Governor, GovernorPreventLateQuorum) returns (uint256) {
-        return super._castVote(proposalId, account, support, reason, data);
+        return super._castVote(proposalId, account, support, reason, params);
     }
 }
diff --git a/test/governance/Governor.test.js b/test/governance/Governor.test.js
index 290e0bf6944..7156abeabff 100644
--- a/test/governance/Governor.test.js
+++ b/test/governance/Governor.test.js
@@ -41,7 +41,7 @@ contract('Governor', function (accounts) {
   shouldSupportInterfaces([
     'ERC165',
     'Governor',
-    'GovernorWithData',
+    'GovernorWithParams',
   ]);
 
   it('deployment check', async function () {
diff --git a/test/governance/extensions/GovernorTimelockCompound.test.js b/test/governance/extensions/GovernorTimelockCompound.test.js
index 3f566296bab..e623c4571dd 100644
--- a/test/governance/extensions/GovernorTimelockCompound.test.js
+++ b/test/governance/extensions/GovernorTimelockCompound.test.js
@@ -48,7 +48,7 @@ contract('GovernorTimelockCompound', function (accounts) {
   shouldSupportInterfaces([
     'ERC165',
     'Governor',
-    'GovernorWithData',
+    'GovernorWithParams',
     'GovernorTimelock',
   ]);
 
diff --git a/test/governance/extensions/GovernorTimelockControl.test.js b/test/governance/extensions/GovernorTimelockControl.test.js
index 9604504d205..ade1c545a7c 100644
--- a/test/governance/extensions/GovernorTimelockControl.test.js
+++ b/test/governance/extensions/GovernorTimelockControl.test.js
@@ -43,7 +43,7 @@ contract('GovernorTimelockControl', function (accounts) {
   shouldSupportInterfaces([
     'ERC165',
     'Governor',
-    'GovernorWithData',
+    'GovernorWithParams',
     'GovernorTimelock',
   ]);
 
diff --git a/test/utils/introspection/SupportsInterface.behavior.js b/test/utils/introspection/SupportsInterface.behavior.js
index 1915a9a2946..054b58452b2 100644
--- a/test/utils/introspection/SupportsInterface.behavior.js
+++ b/test/utils/introspection/SupportsInterface.behavior.js
@@ -69,7 +69,7 @@ const INTERFACES = {
     'castVoteWithReason(uint256,uint8,string)',
     'castVoteBySig(uint256,uint8,uint8,bytes32,bytes32)',
   ],
-  GovernorWithData: [
+  GovernorWithParams: [
     'name()',
     'version()',
     'COUNTING_MODE()',
@@ -85,9 +85,9 @@ const INTERFACES = {
     'propose(address[],uint256[],bytes[],string)',
     'execute(address[],uint256[],bytes[],bytes32)',
     'castVote(uint256,uint8)',
-    'castVoteWithData(uint256,uint8,bytes)',
+    'castVoteWithParams(uint256,uint8,bytes)',
     'castVoteWithReason(uint256,uint8,string)',
-    'castVoteWithReasonAndData(uint256,uint8,string,bytes)',
+    'castVoteWithReasonAndParams(uint256,uint8,string,bytes)',
     'castVoteBySig(uint256,uint8,uint8,bytes32,bytes32)',
   ],
   GovernorTimelock: [

From 287aa4fe70fd7b23ecb34a238fd6c59a170db272 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Wed, 22 Dec 2021 10:16:43 -0500
Subject: [PATCH 04/19] Remove castVoteWithParams without reason parameter

---
 contracts/governance/Governor.sol               | 17 ++---------------
 contracts/governance/IGovernor.sol              | 11 -----------
 .../introspection/SupportsInterface.behavior.js |  1 -
 3 files changed, 2 insertions(+), 27 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 9a7b2d8ecc0..37713779855 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -87,10 +87,9 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
      */
     function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC165) returns (bool) {
         // In addition to the current interfaceId, also support previous version of the interfaceId that did not
-        // include the castVoteWithParams() and castVoteWithReasonAndParams() functions as standard
+        // include the castVoteWithReasonAndParams() function as standard
         return
-            interfaceId ==
-            (type(IGovernor).interfaceId ^ this.castVoteWithReasonAndParams.selector ^ this.castVoteWithParams.selector) ||
+            interfaceId == (type(IGovernor).interfaceId ^ this.castVoteWithReasonAndParams.selector) ||
             interfaceId == type(IGovernor).interfaceId ||
             super.supportsInterface(interfaceId);
     }
@@ -370,18 +369,6 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         return _castVote(proposalId, voter, support, "", "");
     }
 
-    /**
-     * @dev See {IGovernor-castVoteWithParams}.
-     */
-    function castVoteWithParams(
-        uint256 proposalId,
-        uint8 support,
-        bytes memory params
-    ) public virtual override returns (uint256) {
-        address voter = _msgSender();
-        return _castVote(proposalId, voter, support, "", params);
-    }
-
     /**
      * @dev See {IGovernor-castVoteWithReason}.
      */
diff --git a/contracts/governance/IGovernor.sol b/contracts/governance/IGovernor.sol
index 32777d5831a..6991ca7587e 100644
--- a/contracts/governance/IGovernor.sol
+++ b/contracts/governance/IGovernor.sol
@@ -192,17 +192,6 @@ abstract contract IGovernor is IERC165 {
      */
     function castVote(uint256 proposalId, uint8 support) public virtual returns (uint256 balance);
 
-    /**
-     * @dev Cast a vote with additional encoded parameters
-     *
-     * Emits a {VoteCast} event.
-     */
-    function castVoteWithParams(
-        uint256 proposalId,
-        uint8 support,
-        bytes memory params
-    ) public virtual returns (uint256 balance);
-
     /**
      * @dev Cast a vote with a reason
      *
diff --git a/test/utils/introspection/SupportsInterface.behavior.js b/test/utils/introspection/SupportsInterface.behavior.js
index 054b58452b2..5c1b6d4f02d 100644
--- a/test/utils/introspection/SupportsInterface.behavior.js
+++ b/test/utils/introspection/SupportsInterface.behavior.js
@@ -85,7 +85,6 @@ const INTERFACES = {
     'propose(address[],uint256[],bytes[],string)',
     'execute(address[],uint256[],bytes[],bytes32)',
     'castVote(uint256,uint8)',
-    'castVoteWithParams(uint256,uint8,bytes)',
     'castVoteWithReason(uint256,uint8,string)',
     'castVoteWithReasonAndParams(uint256,uint8,string,bytes)',
     'castVoteBySig(uint256,uint8,uint8,bytes32,bytes32)',

From 92e939ffe222884ba36f0321ec0ed22c6713c271 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Wed, 22 Dec 2021 10:26:28 -0500
Subject: [PATCH 05/19] Add a virtual method specifying default additional
 voting params

---
 contracts/governance/Governor.sol | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 37713779855..bdb047ed4f0 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -211,6 +211,16 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         bytes memory params
     ) internal virtual;
 
+    /**
+     * @dev Default additional encoded parameters used by castVote methods that don't include them
+     *
+     * Note: Should be overriden by specific implementations to use an appropriate value, the
+     * meaning of the additional params, in the context of that implementation
+     */
+    function _defaultParams() internal view virtual returns (bytes memory) {
+        return "";
+    }
+
     /**
      * @dev See {IGovernor-propose}.
      */
@@ -366,7 +376,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
      */
     function castVote(uint256 proposalId, uint8 support) public virtual override returns (uint256) {
         address voter = _msgSender();
-        return _castVote(proposalId, voter, support, "", "");
+        return _castVote(proposalId, voter, support, "", _defaultParams());
     }
 
     /**
@@ -377,7 +387,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         uint8 support,
         string calldata reason
     ) public virtual override returns (uint256) {
-        return castVoteWithReasonAndParams(proposalId, support, reason, "");
+        return castVoteWithReasonAndParams(proposalId, support, reason, _defaultParams());
     }
 
     /**
@@ -409,7 +419,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
             r,
             s
         );
-        return _castVote(proposalId, voter, support, "", "");
+        return _castVote(proposalId, voter, support, "", _defaultParams());
     }
 
     /**

From b7eb845bbab2cab1399dec4ad087feba2f3cd53d Mon Sep 17 00:00:00 2001
From: Hadrien Croubois <hadrien.croubois@gmail.com>
Date: Thu, 13 Jan 2022 16:35:17 +0100
Subject: [PATCH 06/19] Extend parameterized Governor customization to include
 vote weight calculation

---
 contracts/governance/Governor.sol              | 18 +++++++++++++++++-
 .../governance/extensions/GovernorVotes.sol    |  8 ++++++--
 .../extensions/GovernorVotesComp.sol           |  8 ++++++--
 contracts/mocks/GovernorCompMock.sol           | 10 ----------
 .../mocks/GovernorCompatibilityBravoMock.sol   | 10 ----------
 contracts/mocks/GovernorMock.sol               | 10 ----------
 .../mocks/GovernorTimelockCompoundMock.sol     | 10 ----------
 .../mocks/GovernorTimelockControlMock.sol      | 10 ----------
 contracts/mocks/GovernorVoteMock.sol           | 10 ----------
 contracts/mocks/wizard/MyGovernor1.sol         |  9 ---------
 contracts/mocks/wizard/MyGovernor2.sol         |  9 ---------
 contracts/mocks/wizard/MyGovernor3.sol         |  9 ---------
 12 files changed, 29 insertions(+), 92 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index bdb047ed4f0..eaa1256d9d9 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -198,6 +198,15 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
      */
     function _voteSucceeded(uint256 proposalId) internal view virtual returns (bool);
 
+    /**
+     * @dev Check the voting weight of an account.
+     */
+    function _getVotes(
+        address account,
+        uint256 blockNumber,
+        bytes memory params
+    ) internal view virtual returns (uint256);
+
     /**
      * @dev Register a vote with a given support and voting weight.
      *
@@ -371,6 +380,13 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         return proposalId;
     }
 
+    /**
+     * @dev See {IGovernor-getVotes}.
+     */
+    function getVotes(address account, uint256 blockNumber) public view virtual override returns (uint256) {
+        return _getVotes(account, blockNumber, _defaultParams());
+    }
+
     /**
      * @dev See {IGovernor-castVote}.
      */
@@ -438,7 +454,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         ProposalCore storage proposal = _proposals[proposalId];
         require(state(proposalId) == ProposalState.Active, "Governor: vote not currently active");
 
-        uint256 weight = getVotes(account, proposal.voteStart.getDeadline());
+        uint256 weight = _getVotes(account, proposal.voteStart.getDeadline(), params);
         _countVote(proposalId, account, support, weight, params);
 
         emit VoteCast(account, proposalId, support, weight, reason);
diff --git a/contracts/governance/extensions/GovernorVotes.sol b/contracts/governance/extensions/GovernorVotes.sol
index 75f56356f3c..f0a2276fb38 100644
--- a/contracts/governance/extensions/GovernorVotes.sol
+++ b/contracts/governance/extensions/GovernorVotes.sol
@@ -19,9 +19,13 @@ abstract contract GovernorVotes is Governor {
     }
 
     /**
-     * Read the voting weight from the token's built in snapshot mechanism (see {IGovernor-getVotes}).
+     * Read the voting weight from the token's built in snapshot mechanism (see {Governor-_getVotes}).
      */
-    function getVotes(address account, uint256 blockNumber) public view virtual override returns (uint256) {
+    function _getVotes(
+        address account,
+        uint256 blockNumber,
+        bytes memory /*params*/
+    ) internal view virtual override returns (uint256) {
         return token.getPastVotes(account, blockNumber);
     }
 }
diff --git a/contracts/governance/extensions/GovernorVotesComp.sol b/contracts/governance/extensions/GovernorVotesComp.sol
index 9eb87a35fa4..c31c9583b5a 100644
--- a/contracts/governance/extensions/GovernorVotesComp.sol
+++ b/contracts/governance/extensions/GovernorVotesComp.sol
@@ -19,9 +19,13 @@ abstract contract GovernorVotesComp is Governor {
     }
 
     /**
-     * Read the voting weight from the token's built in snapshot mechanism (see {IGovernor-getVotes}).
+     * Read the voting weight from the token's built in snapshot mechanism (see {Governor-_getVotes}).
      */
-    function getVotes(address account, uint256 blockNumber) public view virtual override returns (uint256) {
+    function _getVotes(
+        address account,
+        uint256 blockNumber,
+        bytes memory /*params*/
+    ) internal view virtual override returns (uint256) {
         return token.getPriorVotes(account, blockNumber);
     }
 }
diff --git a/contracts/mocks/GovernorCompMock.sol b/contracts/mocks/GovernorCompMock.sol
index 9dcbc536d0e..c2d8733e032 100644
--- a/contracts/mocks/GovernorCompMock.sol
+++ b/contracts/mocks/GovernorCompMock.sol
@@ -28,14 +28,4 @@ contract GovernorCompMock is GovernorVotesComp, GovernorCountingSimple {
     ) public returns (uint256 proposalId) {
         return _cancel(targets, values, calldatas, salt);
     }
-
-    function getVotes(address account, uint256 blockNumber)
-        public
-        view
-        virtual
-        override(IGovernor, GovernorVotesComp)
-        returns (uint256)
-    {
-        return super.getVotes(account, blockNumber);
-    }
 }
diff --git a/contracts/mocks/GovernorCompatibilityBravoMock.sol b/contracts/mocks/GovernorCompatibilityBravoMock.sol
index 60afbb918e9..8f295f62faa 100644
--- a/contracts/mocks/GovernorCompatibilityBravoMock.sol
+++ b/contracts/mocks/GovernorCompatibilityBravoMock.sol
@@ -124,16 +124,6 @@ contract GovernorCompatibilityBravoMock is
         return super._cancel(targets, values, calldatas, salt);
     }
 
-    function getVotes(address account, uint256 blockNumber)
-        public
-        view
-        virtual
-        override(IGovernor, GovernorVotesComp)
-        returns (uint256)
-    {
-        return super.getVotes(account, blockNumber);
-    }
-
     function _executor() internal view virtual override(Governor, GovernorTimelockCompound) returns (address) {
         return super._executor();
     }
diff --git a/contracts/mocks/GovernorMock.sol b/contracts/mocks/GovernorMock.sol
index 85233f55951..dafb0a0a7a5 100644
--- a/contracts/mocks/GovernorMock.sol
+++ b/contracts/mocks/GovernorMock.sol
@@ -35,16 +35,6 @@ contract GovernorMock is
         return _cancel(targets, values, calldatas, salt);
     }
 
-    function getVotes(address account, uint256 blockNumber)
-        public
-        view
-        virtual
-        override(IGovernor, GovernorVotes)
-        returns (uint256)
-    {
-        return super.getVotes(account, blockNumber);
-    }
-
     function proposalThreshold() public view override(Governor, GovernorSettings) returns (uint256) {
         return super.proposalThreshold();
     }
diff --git a/contracts/mocks/GovernorTimelockCompoundMock.sol b/contracts/mocks/GovernorTimelockCompoundMock.sol
index aeba5b86a80..88a8829280c 100644
--- a/contracts/mocks/GovernorTimelockCompoundMock.sol
+++ b/contracts/mocks/GovernorTimelockCompoundMock.sol
@@ -92,16 +92,6 @@ contract GovernorTimelockCompoundMock is
         return super._cancel(targets, values, calldatas, salt);
     }
 
-    function getVotes(address account, uint256 blockNumber)
-        public
-        view
-        virtual
-        override(IGovernor, GovernorVotes)
-        returns (uint256)
-    {
-        return super.getVotes(account, blockNumber);
-    }
-
     function _executor() internal view virtual override(Governor, GovernorTimelockCompound) returns (address) {
         return super._executor();
     }
diff --git a/contracts/mocks/GovernorTimelockControlMock.sol b/contracts/mocks/GovernorTimelockControlMock.sol
index 6150b7b3c6d..455eac9bacc 100644
--- a/contracts/mocks/GovernorTimelockControlMock.sol
+++ b/contracts/mocks/GovernorTimelockControlMock.sol
@@ -92,16 +92,6 @@ contract GovernorTimelockControlMock is
         return super._cancel(targets, values, calldatas, descriptionHash);
     }
 
-    function getVotes(address account, uint256 blockNumber)
-        public
-        view
-        virtual
-        override(IGovernor, GovernorVotes)
-        returns (uint256)
-    {
-        return super.getVotes(account, blockNumber);
-    }
-
     function _executor() internal view virtual override(Governor, GovernorTimelockControl) returns (address) {
         return super._executor();
     }
diff --git a/contracts/mocks/GovernorVoteMock.sol b/contracts/mocks/GovernorVoteMock.sol
index 23ccf6bc09c..60a3d41355e 100644
--- a/contracts/mocks/GovernorVoteMock.sol
+++ b/contracts/mocks/GovernorVoteMock.sol
@@ -28,14 +28,4 @@ contract GovernorVoteMocks is GovernorVotes, GovernorCountingSimple {
     ) public returns (uint256 proposalId) {
         return _cancel(targets, values, calldatas, salt);
     }
-
-    function getVotes(address account, uint256 blockNumber)
-        public
-        view
-        virtual
-        override(IGovernor, GovernorVotes)
-        returns (uint256)
-    {
-        return super.getVotes(account, blockNumber);
-    }
 }
diff --git a/contracts/mocks/wizard/MyGovernor1.sol b/contracts/mocks/wizard/MyGovernor1.sol
index bd524ee55a2..a80d8400c5e 100644
--- a/contracts/mocks/wizard/MyGovernor1.sol
+++ b/contracts/mocks/wizard/MyGovernor1.sol
@@ -40,15 +40,6 @@ contract MyGovernor1 is
         return super.quorum(blockNumber);
     }
 
-    function getVotes(address account, uint256 blockNumber)
-        public
-        view
-        override(IGovernor, GovernorVotes)
-        returns (uint256)
-    {
-        return super.getVotes(account, blockNumber);
-    }
-
     function state(uint256 proposalId) public view override(Governor, GovernorTimelockControl) returns (ProposalState) {
         return super.state(proposalId);
     }
diff --git a/contracts/mocks/wizard/MyGovernor2.sol b/contracts/mocks/wizard/MyGovernor2.sol
index 3a5c983e0b3..34c608c5cc2 100644
--- a/contracts/mocks/wizard/MyGovernor2.sol
+++ b/contracts/mocks/wizard/MyGovernor2.sol
@@ -46,15 +46,6 @@ contract MyGovernor2 is
         return super.quorum(blockNumber);
     }
 
-    function getVotes(address account, uint256 blockNumber)
-        public
-        view
-        override(IGovernor, GovernorVotes)
-        returns (uint256)
-    {
-        return super.getVotes(account, blockNumber);
-    }
-
     function state(uint256 proposalId) public view override(Governor, GovernorTimelockControl) returns (ProposalState) {
         return super.state(proposalId);
     }
diff --git a/contracts/mocks/wizard/MyGovernor3.sol b/contracts/mocks/wizard/MyGovernor3.sol
index 835a893a3a4..70e4e87f046 100644
--- a/contracts/mocks/wizard/MyGovernor3.sol
+++ b/contracts/mocks/wizard/MyGovernor3.sol
@@ -44,15 +44,6 @@ contract MyGovernor is
         return super.quorum(blockNumber);
     }
 
-    function getVotes(address account, uint256 blockNumber)
-        public
-        view
-        override(IGovernor, GovernorVotes)
-        returns (uint256)
-    {
-        return super.getVotes(account, blockNumber);
-    }
-
     function state(uint256 proposalId)
         public
         view

From ead0d51b8f12b9dfb659685809a852068e5e3d25 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Mon, 17 Jan 2022 10:28:24 -0500
Subject: [PATCH 07/19] Mock and test usage of Govenance extension params

---
 contracts/mocks/GovernorWithParamsMock.sol    |  61 ++++++++
 .../extensions/GovernorWithParams.test.js     | 146 ++++++++++++++++++
 2 files changed, 207 insertions(+)
 create mode 100644 contracts/mocks/GovernorWithParamsMock.sol
 create mode 100644 test/governance/extensions/GovernorWithParams.test.js

diff --git a/contracts/mocks/GovernorWithParamsMock.sol b/contracts/mocks/GovernorWithParamsMock.sol
new file mode 100644
index 00000000000..0b3dc133906
--- /dev/null
+++ b/contracts/mocks/GovernorWithParamsMock.sol
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "../governance/extensions/GovernorCountingSimple.sol";
+import "../governance/extensions/GovernorVotes.sol";
+
+contract GovernorWithParamsMock is GovernorVotes, GovernorCountingSimple {
+    event CountParams(uint256 uintParam, string strParam);
+
+    constructor(string memory name_, IVotes token_) Governor(name_) GovernorVotes(token_) {}
+
+    function quorum(uint256) public pure override returns (uint256) {
+        return 0;
+    }
+
+    function votingDelay() public pure override returns (uint256) {
+        return 4;
+    }
+
+    function votingPeriod() public pure override returns (uint256) {
+        return 16;
+    }
+
+    function _getVotes(
+        address account,
+        uint256 blockNumber,
+        bytes memory params
+    ) internal view virtual override(Governor, GovernorVotes) returns (uint256) {
+        uint256 reduction = 0;
+        // If the user provides parameters, we reduce the voting weight by the amount of the integer param
+        if (params.length > 0) {
+            (reduction, ) = abi.decode(params, (uint256, string));
+        }
+        // reverts on overflow
+        return GovernorVotes._getVotes(account, blockNumber, params) - reduction;
+    }
+
+    function _countVote(
+        uint256 proposalId,
+        address account,
+        uint8 support,
+        uint256 weight,
+        bytes memory params
+    ) internal virtual override(Governor, GovernorCountingSimple) {
+        if (params.length > 0) {
+            (uint256 _uintParam, string memory _strParam) = abi.decode(params, (uint256, string));
+            emit CountParams(_uintParam, _strParam);
+        }
+        return GovernorCountingSimple._countVote(proposalId, account, support, weight, params);
+    }
+
+    function cancel(
+        address[] memory targets,
+        uint256[] memory values,
+        bytes[] memory calldatas,
+        bytes32 salt
+    ) public returns (uint256 proposalId) {
+        return _cancel(targets, values, calldatas, salt);
+    }
+}
diff --git a/test/governance/extensions/GovernorWithParams.test.js b/test/governance/extensions/GovernorWithParams.test.js
new file mode 100644
index 00000000000..14dfbaf35de
--- /dev/null
+++ b/test/governance/extensions/GovernorWithParams.test.js
@@ -0,0 +1,146 @@
+const { BN, expectEvent, expectRevert, time } = require('@openzeppelin/test-helpers');
+const { web3 } = require('@openzeppelin/test-helpers/src/setup');
+const Enums = require('../../helpers/enums');
+
+const { runGovernorWorkflow } = require('../GovernorWorkflow.behavior');
+
+const Token = artifacts.require('ERC20VotesCompMock');
+const Governor = artifacts.require('GovernorWithParamsMock');
+const CallReceiver = artifacts.require('CallReceiverMock');
+
+contract('GovernorWithParams', function (accounts) {
+  const [owner, proposer, voter1, voter2, voter3, voter4] = accounts;
+
+  const name = 'OZ-Governor';
+  const tokenName = 'MockToken';
+  const tokenSymbol = 'MTKN';
+  const tokenSupply = web3.utils.toWei('100');
+  const votingDelay = new BN(4);
+  const votingPeriod = new BN(16);
+
+  beforeEach(async function () {
+    this.owner = owner;
+    this.token = await Token.new(tokenName, tokenSymbol);
+    this.mock = await Governor.new(name, this.token.address);
+    this.receiver = await CallReceiver.new();
+    await this.token.mint(owner, tokenSupply);
+    await this.token.delegate(voter1, { from: voter1 });
+    await this.token.delegate(voter2, { from: voter2 });
+    await this.token.delegate(voter3, { from: voter3 });
+    await this.token.delegate(voter4, { from: voter4 });
+  });
+
+  it('deployment check', async function () {
+    expect(await this.mock.name()).to.be.equal(name);
+    expect(await this.mock.token()).to.be.equal(this.token.address);
+    expect(await this.mock.votingDelay()).to.be.bignumber.equal(votingDelay);
+    expect(await this.mock.votingPeriod()).to.be.bignumber.equal(votingPeriod);
+  });
+
+  describe('nominal is unaffected', function () {
+    beforeEach(async function () {
+      this.settings = {
+        proposal: [
+          [this.receiver.address],
+          [0],
+          [this.receiver.contract.methods.mockFunction().encodeABI()],
+          '<proposal description>',
+        ],
+        proposer,
+        tokenHolder: owner,
+        voters: [
+          { voter: voter1, weight: web3.utils.toWei('1'), support: Enums.VoteType.For, reason: 'This is nice' },
+          { voter: voter2, weight: web3.utils.toWei('7'), support: Enums.VoteType.For },
+          { voter: voter3, weight: web3.utils.toWei('5'), support: Enums.VoteType.Against },
+          { voter: voter4, weight: web3.utils.toWei('2'), support: Enums.VoteType.Abstain },
+        ],
+      };
+    });
+
+    afterEach(async function () {
+      expect(await this.mock.hasVoted(this.id, owner)).to.be.equal(false);
+      expect(await this.mock.hasVoted(this.id, voter1)).to.be.equal(true);
+      expect(await this.mock.hasVoted(this.id, voter2)).to.be.equal(true);
+
+      await this.mock.proposalVotes(this.id).then((result) => {
+        for (const [key, value] of Object.entries(Enums.VoteType)) {
+          expect(result[`${key.toLowerCase()}Votes`]).to.be.bignumber.equal(
+            Object.values(this.settings.voters)
+              .filter(({ support }) => support === value)
+              .reduce((acc, { weight }) => acc.add(new BN(weight)), new BN('0')),
+          );
+        }
+      });
+
+      const startBlock = new BN(this.receipts.propose.blockNumber).add(votingDelay);
+      const endBlock = new BN(this.receipts.propose.blockNumber).add(votingDelay).add(votingPeriod);
+      expect(await this.mock.proposalSnapshot(this.id)).to.be.bignumber.equal(startBlock);
+      expect(await this.mock.proposalDeadline(this.id)).to.be.bignumber.equal(endBlock);
+
+      expectEvent(this.receipts.propose, 'ProposalCreated', {
+        proposalId: this.id,
+        proposer,
+        targets: this.settings.proposal[0],
+        // values: this.settings.proposal[1].map(value => new BN(value)),
+        signatures: this.settings.proposal[2].map(() => ''),
+        calldatas: this.settings.proposal[2],
+        startBlock,
+        endBlock,
+        description: this.settings.proposal[3],
+      });
+
+      this.receipts.castVote.filter(Boolean).forEach((vote) => {
+        const { voter } = vote.logs.filter(({ event }) => event === 'VoteCast').find(Boolean).args;
+        expectEvent(
+          vote,
+          'VoteCast',
+          this.settings.voters.find(({ address }) => address === voter),
+        );
+      });
+      expectEvent(this.receipts.execute, 'ProposalExecuted', { proposalId: this.id });
+      await expectEvent.inTransaction(this.receipts.execute.transactionHash, this.receiver, 'MockFunctionCalled');
+    });
+    runGovernorWorkflow();
+  });
+
+  describe('Voting with params is properly supported', function () {
+      const voter2Weight = web3.utils.toWei('1.0');
+    beforeEach(async function () {
+      this.settings = {
+        proposal: [
+          [this.receiver.address],
+          [0],
+          [this.receiver.contract.methods.mockFunction().encodeABI()],
+          '<proposal description>',
+        ],
+        proposer,
+        tokenHolder: owner,
+        voters: [
+          { voter: voter1, weight: web3.utils.toWei('0.2'), support: Enums.VoteType.Against },
+          { voter: voter2, weight: voter2Weight }, // do not actually vote, only getting tokens
+          { voter: voter3, weight: web3.utils.toWei('0.9') }, // do not actually vote, only getting tokens
+        ],
+        steps: {
+          wait: { enable: false },
+          execute: { enable: false },
+        },
+      };
+    });
+
+    afterEach(async function () {
+      expect(await this.mock.state(this.id)).to.be.bignumber.equal(Enums.ProposalState.Active);
+
+      const uintParam = new BN(1);
+      const strParam = 'These are my params';
+      const reducedWeight =  (new BN(voter2Weight)).sub(uintParam);
+      const params = web3.eth.abi.encodeParameters(['uint256', 'string'], [uintParam, strParam]);
+      const tx = await this.mock.castVoteWithReasonAndParams(this.id, Enums.VoteType.For, '', params, { from: voter2 });
+
+      expectEvent(tx, 'CountParams', { uintParam, strParam });
+      expectEvent(tx, 'VoteCast', {voter: voter2, weight: reducedWeight});
+
+      // TODO: Cast vote with voter3 using params & signature; confirm events exist in tx receipt
+    });
+    runGovernorWorkflow();
+  });
+});

From 0b49a653d3e3507154e47c38e3140f1cfdf93757 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Mon, 17 Jan 2022 12:36:49 -0500
Subject: [PATCH 08/19] Implement and test Govenor
 castVoteWithReasonAndParamsBySig method

---
 contracts/governance/Governor.sol             |  39 ++++++-
 contracts/governance/IGovernor.sol            |  17 ++-
 .../extensions/GovernorWithParams.test.js     | 101 ++++++++++++++++--
 .../SupportsInterface.behavior.js             |   1 +
 4 files changed, 149 insertions(+), 9 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index eaa1256d9d9..4cbd8909d4d 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -30,6 +30,8 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
     using Timers for Timers.BlockNumber;
 
     bytes32 public constant BALLOT_TYPEHASH = keccak256("Ballot(uint256 proposalId,uint8 support)");
+    bytes32 public constant EXTENDED_BALLOT_TYPEHASH =
+        keccak256("ExtendedBallot(uint256 proposalId,uint8 support,string reason,bytes params)");
 
     struct ProposalCore {
         Timers.BlockNumber voteStart;
@@ -89,7 +91,10 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         // In addition to the current interfaceId, also support previous version of the interfaceId that did not
         // include the castVoteWithReasonAndParams() function as standard
         return
-            interfaceId == (type(IGovernor).interfaceId ^ this.castVoteWithReasonAndParams.selector) ||
+            interfaceId ==
+            (type(IGovernor).interfaceId ^
+                this.castVoteWithReasonAndParams.selector ^
+                this.castVoteWithReasonAndParamsBySig.selector) ||
             interfaceId == type(IGovernor).interfaceId ||
             super.supportsInterface(interfaceId);
     }
@@ -438,6 +443,38 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         return _castVote(proposalId, voter, support, "", _defaultParams());
     }
 
+    /**
+     * @dev See {IGovernor-castVoteWithReasonAndParamsBySig}.
+     */
+    function castVoteWithReasonAndParamsBySig(
+        uint256 proposalId,
+        uint8 support,
+        string calldata reason,
+        bytes memory params,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) public virtual override returns (uint256) {
+        address voter = ECDSA.recover(
+            _hashTypedDataV4(
+                keccak256(
+                    abi.encode(
+                        EXTENDED_BALLOT_TYPEHASH,
+                        proposalId,
+                        support,
+                        keccak256(bytes(reason)),
+                        keccak256(params)
+                    )
+                )
+            ),
+            v,
+            r,
+            s
+        );
+
+        return _castVote(proposalId, voter, support, reason, params);
+    }
+
     /**
      * @dev Internal vote casting mechanism: Check that the vote is pending, that it has not been cast yet, retrieve
      * voting weight using {IGovernor-getVotes} and call the {_countVote} internal function.
diff --git a/contracts/governance/IGovernor.sol b/contracts/governance/IGovernor.sol
index 6991ca7587e..d975d2c99e3 100644
--- a/contracts/governance/IGovernor.sol
+++ b/contracts/governance/IGovernor.sol
@@ -216,7 +216,7 @@ abstract contract IGovernor is IERC165 {
     ) public virtual returns (uint256 balance);
 
     /**
-     * @dev Cast a vote using the user cryptographic signature.
+     * @dev Cast a vote using the user's cryptographic signature.
      *
      * Emits a {VoteCast} event.
      */
@@ -227,4 +227,19 @@ abstract contract IGovernor is IERC165 {
         bytes32 r,
         bytes32 s
     ) public virtual returns (uint256 balance);
+
+    /**
+     * @dev Cast a vote with a reason and additional encoded parameters using the user's cryptographic signature.
+     *
+     * Emits a {VoteCast} event.
+     */
+    function castVoteWithReasonAndParamsBySig(
+        uint256 proposalId,
+        uint8 support,
+        string calldata reason,
+        bytes memory params,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) public virtual returns (uint256 balance);
 }
diff --git a/test/governance/extensions/GovernorWithParams.test.js b/test/governance/extensions/GovernorWithParams.test.js
index 14dfbaf35de..6afb7dd5ed5 100644
--- a/test/governance/extensions/GovernorWithParams.test.js
+++ b/test/governance/extensions/GovernorWithParams.test.js
@@ -1,6 +1,10 @@
-const { BN, expectEvent, expectRevert, time } = require('@openzeppelin/test-helpers');
+const { BN, constants, expectEvent } = require('@openzeppelin/test-helpers');
 const { web3 } = require('@openzeppelin/test-helpers/src/setup');
 const Enums = require('../../helpers/enums');
+const ethSigUtil = require('eth-sig-util');
+const Wallet = require('ethereumjs-wallet').default;
+const { EIP712Domain } = require('../../helpers/eip712');
+const { fromRpcSig } = require('ethereumjs-util');
 
 const { runGovernorWorkflow } = require('../GovernorWorkflow.behavior');
 
@@ -12,6 +16,7 @@ contract('GovernorWithParams', function (accounts) {
   const [owner, proposer, voter1, voter2, voter3, voter4] = accounts;
 
   const name = 'OZ-Governor';
+  const version = '1';
   const tokenName = 'MockToken';
   const tokenSymbol = 'MTKN';
   const tokenSupply = web3.utils.toWei('100');
@@ -104,7 +109,7 @@ contract('GovernorWithParams', function (accounts) {
   });
 
   describe('Voting with params is properly supported', function () {
-      const voter2Weight = web3.utils.toWei('1.0');
+    const voter2Weight = web3.utils.toWei('1.0');
     beforeEach(async function () {
       this.settings = {
         proposal: [
@@ -117,8 +122,7 @@ contract('GovernorWithParams', function (accounts) {
         tokenHolder: owner,
         voters: [
           { voter: voter1, weight: web3.utils.toWei('0.2'), support: Enums.VoteType.Against },
-          { voter: voter2, weight: voter2Weight }, // do not actually vote, only getting tokens
-          { voter: voter3, weight: web3.utils.toWei('0.9') }, // do not actually vote, only getting tokens
+          { voter: voter2, weight: voter2Weight }, // do not actually vote, only getting tokenss
         ],
         steps: {
           wait: { enable: false },
@@ -132,14 +136,97 @@ contract('GovernorWithParams', function (accounts) {
 
       const uintParam = new BN(1);
       const strParam = 'These are my params';
-      const reducedWeight =  (new BN(voter2Weight)).sub(uintParam);
+      const reducedWeight = new BN(voter2Weight).sub(uintParam);
       const params = web3.eth.abi.encodeParameters(['uint256', 'string'], [uintParam, strParam]);
       const tx = await this.mock.castVoteWithReasonAndParams(this.id, Enums.VoteType.For, '', params, { from: voter2 });
 
       expectEvent(tx, 'CountParams', { uintParam, strParam });
-      expectEvent(tx, 'VoteCast', {voter: voter2, weight: reducedWeight});
+      expectEvent(tx, 'VoteCast', { voter: voter2, weight: reducedWeight });
+    });
+    runGovernorWorkflow();
+  });
+
+  describe('Voting with params by signature is propoerly supported', function () {
+    const voterBySig = Wallet.generate(); // generate voter by signature wallet
+    const sigVoterWeight = web3.utils.toWei('1.0');
+
+    beforeEach(async function () {
+      this.chainId = await web3.eth.getChainId();
+      this.voter = web3.utils.toChecksumAddress(voterBySig.getAddressString());
+
+      // use delegateBySig to enable vote delegation sig voting wallet
+      const { v, r, s } = fromRpcSig(
+        ethSigUtil.signTypedMessage(voterBySig.getPrivateKey(), {
+          data: {
+            types: {
+              EIP712Domain,
+              Delegation: [
+                { name: 'delegatee', type: 'address' },
+                { name: 'nonce', type: 'uint256' },
+                { name: 'expiry', type: 'uint256' },
+              ],
+            },
+            domain: { name: tokenName, version: '1', chainId: this.chainId, verifyingContract: this.token.address },
+            primaryType: 'Delegation',
+            message: { delegatee: this.voter, nonce: 0, expiry: constants.MAX_UINT256 },
+          },
+        }),
+      );
+      await this.token.delegateBySig(this.voter, 0, constants.MAX_UINT256, v, r, s);
+
+      this.settings = {
+        proposal: [
+          [this.receiver.address],
+          [0],
+          [this.receiver.contract.methods.mockFunction().encodeABI()],
+          '<proposal description>',
+        ],
+        proposer,
+        tokenHolder: owner,
+        voters: [
+          { voter: voter1, weight: web3.utils.toWei('0.2'), support: Enums.VoteType.Against },
+          { voter: this.voter, weight: sigVoterWeight }, // do not actually vote, only getting tokens
+        ],
+        steps: {
+          wait: { enable: false },
+          execute: { enable: false },
+        },
+      };
+    });
 
-      // TODO: Cast vote with voter3 using params & signature; confirm events exist in tx receipt
+    afterEach(async function () {
+      expect(await this.mock.state(this.id)).to.be.bignumber.equal(Enums.ProposalState.Active);
+
+      const reason = 'This is my reason';
+      const uintParam = new BN(1);
+      const strParam = 'These are my params';
+      const reducedWeight = new BN(sigVoterWeight).sub(uintParam);
+      const params = web3.eth.abi.encodeParameters(['uint256', 'string'], [uintParam, strParam]);
+
+      // prepare signature for vote by signature
+      const { v, r, s } = fromRpcSig(
+        ethSigUtil.signTypedMessage(voterBySig.getPrivateKey(), {
+          data: {
+            types: {
+              EIP712Domain,
+              ExtendedBallot: [
+                { name: 'proposalId', type: 'uint256' },
+                { name: 'support', type: 'uint8' },
+                { name: 'reason', type: 'string' },
+                { name: 'params', type: 'bytes' },
+              ],
+            },
+            domain: { name, version, chainId: this.chainId, verifyingContract: this.mock.address },
+            primaryType: 'ExtendedBallot',
+            message: { proposalId: this.id, support: Enums.VoteType.For, reason, params },
+          },
+        }),
+      );
+
+      const tx = await this.mock.castVoteWithReasonAndParamsBySig(this.id, Enums.VoteType.For, reason, params, v, r, s);
+
+      expectEvent(tx, 'CountParams', { uintParam, strParam });
+      expectEvent(tx, 'VoteCast', { voter: this.voter, weight: reducedWeight });
     });
     runGovernorWorkflow();
   });
diff --git a/test/utils/introspection/SupportsInterface.behavior.js b/test/utils/introspection/SupportsInterface.behavior.js
index 5c1b6d4f02d..20281b2101a 100644
--- a/test/utils/introspection/SupportsInterface.behavior.js
+++ b/test/utils/introspection/SupportsInterface.behavior.js
@@ -88,6 +88,7 @@ const INTERFACES = {
     'castVoteWithReason(uint256,uint8,string)',
     'castVoteWithReasonAndParams(uint256,uint8,string,bytes)',
     'castVoteBySig(uint256,uint8,uint8,bytes32,bytes32)',
+    'castVoteWithReasonAndParamsBySig(uint256,uint8,string,bytes,uint8,bytes32,bytes32)',
   ],
   GovernorTimelock: [
     'timelock()',

From 0d5f887a94b2d91ddfb8e84be638354e99c5ccf8 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Thu, 10 Feb 2022 11:17:54 -0500
Subject: [PATCH 09/19] Add VoteCastWithParams event emitted when params are
 included

---
 contracts/governance/Governor.sol             |  6 +++++-
 contracts/governance/IGovernor.sol            | 19 +++++++++++++++++--
 .../extensions/GovernorWithParams.test.js     |  6 +++---
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 4cbd8909d4d..215f0118a25 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -494,7 +494,11 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         uint256 weight = _getVotes(account, proposal.voteStart.getDeadline(), params);
         _countVote(proposalId, account, support, weight, params);
 
-        emit VoteCast(account, proposalId, support, weight, reason);
+        if (params.length == 0) {
+            emit VoteCast(account, proposalId, support, weight, reason);
+        } else {
+            emit VoteCastWithParams(account, proposalId, support, weight, reason, params);
+        }
 
         return weight;
     }
diff --git a/contracts/governance/IGovernor.sol b/contracts/governance/IGovernor.sol
index d975d2c99e3..5eb08d9848b 100644
--- a/contracts/governance/IGovernor.sol
+++ b/contracts/governance/IGovernor.sol
@@ -48,12 +48,27 @@ abstract contract IGovernor is IERC165 {
     event ProposalExecuted(uint256 proposalId);
 
     /**
-     * @dev Emitted when a vote is cast.
+     * @dev Emitted when a vote is cast without params.
      *
-     * Note: `support` values should be seen as buckets. There interpretation depends on the voting module used.
+     * Note: `support` values should be seen as buckets. Their interpretation depends on the voting module used.
      */
     event VoteCast(address indexed voter, uint256 proposalId, uint8 support, uint256 weight, string reason);
 
+    /**
+     * @dev Emitted when a vote is cast with params.
+     *
+     * Note: `support` values should be seen as buckets. Their interpretation depends on the voting module used.
+     * `params` are additional encoded parameters. Their intepepretation also depends on the voting module used.
+     */
+    event VoteCastWithParams(
+        address indexed voter,
+        uint256 proposalId,
+        uint8 support,
+        uint256 weight,
+        string reason,
+        bytes params
+    );
+
     /**
      * @notice module:core
      * @dev Name of the governor instance (used in building the ERC712 domain separator).
diff --git a/test/governance/extensions/GovernorWithParams.test.js b/test/governance/extensions/GovernorWithParams.test.js
index 6afb7dd5ed5..eca66a28ec1 100644
--- a/test/governance/extensions/GovernorWithParams.test.js
+++ b/test/governance/extensions/GovernorWithParams.test.js
@@ -141,12 +141,12 @@ contract('GovernorWithParams', function (accounts) {
       const tx = await this.mock.castVoteWithReasonAndParams(this.id, Enums.VoteType.For, '', params, { from: voter2 });
 
       expectEvent(tx, 'CountParams', { uintParam, strParam });
-      expectEvent(tx, 'VoteCast', { voter: voter2, weight: reducedWeight });
+      expectEvent(tx, 'VoteCastWithParams', { voter: voter2, weight: reducedWeight, params });
     });
     runGovernorWorkflow();
   });
 
-  describe('Voting with params by signature is propoerly supported', function () {
+  describe('Voting with params by signature is properly supported', function () {
     const voterBySig = Wallet.generate(); // generate voter by signature wallet
     const sigVoterWeight = web3.utils.toWei('1.0');
 
@@ -226,7 +226,7 @@ contract('GovernorWithParams', function (accounts) {
       const tx = await this.mock.castVoteWithReasonAndParamsBySig(this.id, Enums.VoteType.For, reason, params, v, r, s);
 
       expectEvent(tx, 'CountParams', { uintParam, strParam });
-      expectEvent(tx, 'VoteCast', { voter: this.voter, weight: reducedWeight });
+      expectEvent(tx, 'VoteCastWithParams', { voter: this.voter, weight: reducedWeight, params });
     });
     runGovernorWorkflow();
   });

From d08f61afa9af7051224d1356f040ebf0ffedcce7 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Thu, 10 Feb 2022 11:42:38 -0500
Subject: [PATCH 10/19] Document changes associated with Governor extension
 params

---
 CHANGELOG.md | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 950e6b24926..5fedc773238 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,17 @@
  * `ERC1155`: Add a `_afterTokenTransfer` hook for improved extensibility. ([#3166](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3166))
  * `DoubleEndedQueue`: a new data structure that supports efficient push and pop to both front and back, useful for FIFO and LIFO queues. ([#3153](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3153))
  * `Governor`: improved security of `onlyGovernance` modifier when using an external executor contract (e.g. a timelock) that can operate without necessarily going through the governance protocol. ([#3147](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3147))
+ * `IGovernor`: Add two new methods to the interface, `castVoteWithReasonAndParams` and `castVoteWithReasonAndParamsBySig`, allowing voting extensions to include more data about how the vote is to be interpreted. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+ * `IGovernor`: Add a new event `VoteCastWithParams` that is emitted when a vote is cast that includes non-empty params data. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+ * `Governor`: Add internal `_defaultParams` method and default implementation. The return value is passed as params data when `castVote` methods without params are called. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+ * `Governor`: Add default `getVotes` implementation which calls virtual internal `_getVotes` method. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+ * `Governor`: Add `EXTENDED_BALLOT_TYPEHASH` used for signature validation in `castVoteWithReasonAndParamsBySig`. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+
+### Breaking changes
+
+* `Governor`: Adds internal virtual `_getVotes` method that must be implemented; this is a breaking change for existing concrete extensions to `Governor`. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+* `Governor`: Adds `params` parameter to internal virtual `_countVote ` method that; this is a breaking change for existing concrete extensions to `Governor`. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+* `Governor`: Does not emit `VoteCast` event when params data is non-empty; instead emits `VoteCastWithParams` event. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
 
 ## 4.5.0 (2022-02-09)
 

From a49eb41c87e39e26ca5c24c7e8a38516597b6a99 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Tue, 15 Feb 2022 16:08:45 -0500
Subject: [PATCH 11/19] Overload _castVote and curry using default parameters

---
 contracts/governance/Governor.sol | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 215f0118a25..f01fff2743e 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -397,7 +397,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
      */
     function castVote(uint256 proposalId, uint8 support) public virtual override returns (uint256) {
         address voter = _msgSender();
-        return _castVote(proposalId, voter, support, "", _defaultParams());
+        return _castVote(proposalId, voter, support, "");
     }
 
     /**
@@ -408,7 +408,8 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         uint8 support,
         string calldata reason
     ) public virtual override returns (uint256) {
-        return castVoteWithReasonAndParams(proposalId, support, reason, _defaultParams());
+        address voter = _msgSender();
+        return _castVote(proposalId, voter, support, reason);
     }
 
     /**
@@ -440,7 +441,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
             r,
             s
         );
-        return _castVote(proposalId, voter, support, "", _defaultParams());
+        return _castVote(proposalId, voter, support, "");
     }
 
     /**
@@ -474,6 +475,20 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
 
         return _castVote(proposalId, voter, support, reason, params);
     }
+    /**
+     * @dev Internal vote casting mechanism: Check that the vote is pending, that it has not been cast yet, retrieve
+     * voting weight using {IGovernor-getVotes} and call the {_countVote} internal function. Uses the _defaultParams().
+     *
+     * Emits a {IGovernor-VoteCast} event.
+     */
+    function _castVote(
+        uint256 proposalId,
+        address account,
+        uint8 support,
+        string memory reason
+    ) internal virtual returns (uint256) {
+        return _castVote(proposalId, account, support, reason, _defaultParams());
+    }
 
     /**
      * @dev Internal vote casting mechanism: Check that the vote is pending, that it has not been cast yet, retrieve

From 0823a4141aabf3719d6608623f2d365eaed75443 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Tue, 15 Feb 2022 16:14:54 -0500
Subject: [PATCH 12/19] Silence compiler warnings by removing parameter name

---
 .../governance/compatibility/GovernorCompatibilityBravo.sol   | 4 +---
 contracts/governance/extensions/GovernorCountingSimple.sol    | 3 +--
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/contracts/governance/compatibility/GovernorCompatibilityBravo.sol b/contracts/governance/compatibility/GovernorCompatibilityBravo.sol
index 5648744463d..1d639f436a0 100644
--- a/contracts/governance/compatibility/GovernorCompatibilityBravo.sol
+++ b/contracts/governance/compatibility/GovernorCompatibilityBravo.sol
@@ -266,10 +266,8 @@ abstract contract GovernorCompatibilityBravo is IGovernorTimelock, IGovernorComp
         address account,
         uint8 support,
         uint256 weight,
-        bytes memory params
+        bytes memory // params
     ) internal virtual override {
-        (params); // silence compiler warnings
-
         ProposalDetails storage details = _proposalDetails[proposalId];
         Receipt storage receipt = details.receipts[account];
 
diff --git a/contracts/governance/extensions/GovernorCountingSimple.sol b/contracts/governance/extensions/GovernorCountingSimple.sol
index 117ae3953e9..a262ce4d836 100644
--- a/contracts/governance/extensions/GovernorCountingSimple.sol
+++ b/contracts/governance/extensions/GovernorCountingSimple.sol
@@ -87,9 +87,8 @@ abstract contract GovernorCountingSimple is Governor {
         address account,
         uint8 support,
         uint256 weight,
-        bytes memory params
+        bytes memory // params
     ) internal virtual override {
-        (params); // silence compiler warnings
         ProposalVote storage proposalvote = _proposalVotes[proposalId];
 
         require(!proposalvote.hasVoted[account], "GovernorVotingSimple: vote already cast");

From 214259cd0aed6592025a79dec87de3bf8db868c1 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Tue, 15 Feb 2022 16:25:03 -0500
Subject: [PATCH 13/19] Fix doc comments related to getting votes

---
 contracts/governance/Governor.sol | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index f01fff2743e..4f58a298c68 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -19,7 +19,7 @@ import "./IGovernor.sol";
  * This contract is abstract and requires several function to be implemented in various modules:
  *
  * - A counting module must implement {quorum}, {_quorumReached}, {_voteSucceeded} and {_countVote}
- * - A voting module must implement {getVotes}
+ * - A voting module must implement {_getVotes}
  * - Additionanly, the {votingPeriod} must also be implemented
  *
  * _Available since v4.3._
@@ -204,7 +204,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
     function _voteSucceeded(uint256 proposalId) internal view virtual returns (bool);
 
     /**
-     * @dev Check the voting weight of an account.
+     * @dev Get the voting weight of `account` at a specific `blockNumber`, for a vote as described by `params`.
      */
     function _getVotes(
         address account,

From 970556e9b727f39004d5b2ef9d8c13a7479e89cd Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Tue, 15 Feb 2022 17:00:51 -0500
Subject: [PATCH 14/19] Simplify Changelog description and include instructions
 for resolving breaking changes

---
 CHANGELOG.md | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5fedc773238..365c4014639 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,17 +7,13 @@
  * `ERC1155`: Add a `_afterTokenTransfer` hook for improved extensibility. ([#3166](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3166))
  * `DoubleEndedQueue`: a new data structure that supports efficient push and pop to both front and back, useful for FIFO and LIFO queues. ([#3153](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3153))
  * `Governor`: improved security of `onlyGovernance` modifier when using an external executor contract (e.g. a timelock) that can operate without necessarily going through the governance protocol. ([#3147](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3147))
- * `IGovernor`: Add two new methods to the interface, `castVoteWithReasonAndParams` and `castVoteWithReasonAndParamsBySig`, allowing voting extensions to include more data about how the vote is to be interpreted. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
- * `IGovernor`: Add a new event `VoteCastWithParams` that is emitted when a vote is cast that includes non-empty params data. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
- * `Governor`: Add internal `_defaultParams` method and default implementation. The return value is passed as params data when `castVote` methods without params are called. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
- * `Governor`: Add default `getVotes` implementation which calls virtual internal `_getVotes` method. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
- * `Governor`: Add `EXTENDED_BALLOT_TYPEHASH` used for signature validation in `castVoteWithReasonAndParamsBySig`. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+ * `Governor`: Add a way to parameterize votes. This can be used to implement voting systems such as fractionalized voting, ERC721 based voting, or any number of other systems. The `params` argument added to `_countVote` method, and included in the newly added `_getVotes` method, can be used by counting and voting modules respectively for such purposes.
 
 ### Breaking changes
 
-* `Governor`: Adds internal virtual `_getVotes` method that must be implemented; this is a breaking change for existing concrete extensions to `Governor`. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
-* `Governor`: Adds `params` parameter to internal virtual `_countVote ` method that; this is a breaking change for existing concrete extensions to `Governor`. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
-* `Governor`: Does not emit `VoteCast` event when params data is non-empty; instead emits `VoteCastWithParams` event. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+* `Governor`: Adds internal virtual `_getVotes` method that must be implemented; this is a breaking change for existing concrete extensions to `Governor`. To fix this on an existing voting module extension, rename `getVotes` to `_getVotes` and add a `bytes memory` argument. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+* `Governor`: Adds `params` parameter to internal virtual `_countVote ` method; this is a breaking change for existing concrete extensions to `Governor`. To fix this on an existing counting module extension, add a `bytes memory` argument to `_countVote`. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
+* `Governor`: Does not emit `VoteCast` event when params data is non-empty; instead emits `VoteCastWithParams` event. To fix this on an integration that consumes the `VoteCast` event, also fetch/monitor `VoteCastWithParams` events. ([#3043](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3043))
 
 ## 4.5.0 (2022-02-09)
 

From 6e2b447283ea014c85a4bd1b700588cd508cda46 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Tue, 15 Feb 2022 17:08:11 -0500
Subject: [PATCH 15/19] Fix Governor linting issue

---
 contracts/governance/Governor.sol | 1 +
 1 file changed, 1 insertion(+)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 4f58a298c68..17ec086df0d 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -475,6 +475,7 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
 
         return _castVote(proposalId, voter, support, reason, params);
     }
+
     /**
      * @dev Internal vote casting mechanism: Check that the vote is pending, that it has not been cast yet, retrieve
      * voting weight using {IGovernor-getVotes} and call the {_countVote} internal function. Uses the _defaultParams().

From 455efe84dc5a8f2f1cd4481961722f880775f1d5 Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Fri, 25 Feb 2022 22:43:39 -0500
Subject: [PATCH 16/19] Add public getVotesWithParams to Governor

---
 contracts/governance/Governor.sol                  | 14 +++++++++++++-
 contracts/governance/IGovernor.sol                 | 10 ++++++++++
 .../introspection/SupportsInterface.behavior.js    |  1 +
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/contracts/governance/Governor.sol b/contracts/governance/Governor.sol
index 17ec086df0d..8907d9468d5 100644
--- a/contracts/governance/Governor.sol
+++ b/contracts/governance/Governor.sol
@@ -94,7 +94,8 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
             interfaceId ==
             (type(IGovernor).interfaceId ^
                 this.castVoteWithReasonAndParams.selector ^
-                this.castVoteWithReasonAndParamsBySig.selector) ||
+                this.castVoteWithReasonAndParamsBySig.selector ^
+                this.getVotesWithParams.selector) ||
             interfaceId == type(IGovernor).interfaceId ||
             super.supportsInterface(interfaceId);
     }
@@ -392,6 +393,17 @@ abstract contract Governor is Context, ERC165, EIP712, IGovernor {
         return _getVotes(account, blockNumber, _defaultParams());
     }
 
+    /**
+     * @dev See {IGovernor-getVotesWithParams}.
+     */
+    function getVotesWithParams(
+        address account,
+        uint256 blockNumber,
+        bytes memory params
+    ) public view virtual override returns (uint256) {
+        return _getVotes(account, blockNumber, params);
+    }
+
     /**
      * @dev See {IGovernor-castVote}.
      */
diff --git a/contracts/governance/IGovernor.sol b/contracts/governance/IGovernor.sol
index 5eb08d9848b..2992c0bf7a7 100644
--- a/contracts/governance/IGovernor.sol
+++ b/contracts/governance/IGovernor.sol
@@ -166,6 +166,16 @@ abstract contract IGovernor is IERC165 {
      */
     function getVotes(address account, uint256 blockNumber) public view virtual returns (uint256);
 
+    /**
+     * @notice module:reputation
+     * @dev Voting power of an `account` at a specific `blockNumber` given additional encoded parameters.
+     */
+    function getVotesWithParams(
+        address account,
+        uint256 blockNumber,
+        bytes memory params
+    ) public view virtual returns (uint256);
+
     /**
      * @notice module:voting
      * @dev Returns weither `account` has cast a vote on `proposalId`.
diff --git a/test/utils/introspection/SupportsInterface.behavior.js b/test/utils/introspection/SupportsInterface.behavior.js
index 20281b2101a..a0aa3d7e50e 100644
--- a/test/utils/introspection/SupportsInterface.behavior.js
+++ b/test/utils/introspection/SupportsInterface.behavior.js
@@ -81,6 +81,7 @@ const INTERFACES = {
     'votingPeriod()',
     'quorum(uint256)',
     'getVotes(address,uint256)',
+    'getVotesWithParams(address,uint256,bytes)',
     'hasVoted(uint256,address)',
     'propose(address[],uint256[],bytes[],string)',
     'execute(address[],uint256[],bytes[],bytes32)',

From 8722c5cade8f3de36bebd14aa1ffdc50cf32572d Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Fri, 25 Feb 2022 22:51:29 -0500
Subject: [PATCH 17/19] Properly call super in GovernorWithParamsMock

---
 contracts/mocks/GovernorWithParamsMock.sol | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/contracts/mocks/GovernorWithParamsMock.sol b/contracts/mocks/GovernorWithParamsMock.sol
index 0b3dc133906..35eb7ade25a 100644
--- a/contracts/mocks/GovernorWithParamsMock.sol
+++ b/contracts/mocks/GovernorWithParamsMock.sol
@@ -33,7 +33,7 @@ contract GovernorWithParamsMock is GovernorVotes, GovernorCountingSimple {
             (reduction, ) = abi.decode(params, (uint256, string));
         }
         // reverts on overflow
-        return GovernorVotes._getVotes(account, blockNumber, params) - reduction;
+        return super._getVotes(account, blockNumber, params) - reduction;
     }
 
     function _countVote(
@@ -47,7 +47,7 @@ contract GovernorWithParamsMock is GovernorVotes, GovernorCountingSimple {
             (uint256 _uintParam, string memory _strParam) = abi.decode(params, (uint256, string));
             emit CountParams(_uintParam, _strParam);
         }
-        return GovernorCountingSimple._countVote(proposalId, account, support, weight, params);
+        return super._countVote(proposalId, account, support, weight, params);
     }
 
     function cancel(

From b4cd7c4caaf5f87a445125cb6be117857559d5ce Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Fri, 25 Feb 2022 23:14:23 -0500
Subject: [PATCH 18/19] Directly verify vote totals when testing parameterized
 voting

---
 test/governance/extensions/GovernorWithParams.test.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/test/governance/extensions/GovernorWithParams.test.js b/test/governance/extensions/GovernorWithParams.test.js
index eca66a28ec1..5b4ac8901d9 100644
--- a/test/governance/extensions/GovernorWithParams.test.js
+++ b/test/governance/extensions/GovernorWithParams.test.js
@@ -7,6 +7,7 @@ const { EIP712Domain } = require('../../helpers/eip712');
 const { fromRpcSig } = require('ethereumjs-util');
 
 const { runGovernorWorkflow } = require('../GovernorWorkflow.behavior');
+const { expect } = require('chai');
 
 const Token = artifacts.require('ERC20VotesCompMock');
 const Governor = artifacts.require('GovernorWithParamsMock');
@@ -142,6 +143,8 @@ contract('GovernorWithParams', function (accounts) {
 
       expectEvent(tx, 'CountParams', { uintParam, strParam });
       expectEvent(tx, 'VoteCastWithParams', { voter: voter2, weight: reducedWeight, params });
+      const votes = await this.mock.proposalVotes(this.id);
+      expect(votes.forVotes).to.be.bignumber.equal(reducedWeight);
     });
     runGovernorWorkflow();
   });
@@ -227,6 +230,8 @@ contract('GovernorWithParams', function (accounts) {
 
       expectEvent(tx, 'CountParams', { uintParam, strParam });
       expectEvent(tx, 'VoteCastWithParams', { voter: this.voter, weight: reducedWeight, params });
+      const votes = await this.mock.proposalVotes(this.id);
+      expect(votes.forVotes).to.be.bignumber.equal(reducedWeight);
     });
     runGovernorWorkflow();
   });

From 78c99685ed9431b9e2a22a401b5f0a1ae683c53f Mon Sep 17 00:00:00 2001
From: Ben DiFrancesco <ben@scopelift.co>
Date: Fri, 25 Feb 2022 23:33:29 -0500
Subject: [PATCH 19/19] Add a note about params to COUNTING_MODE documentation

---
 contracts/governance/IGovernor.sol | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/contracts/governance/IGovernor.sol b/contracts/governance/IGovernor.sol
index 2992c0bf7a7..eaf443a97d1 100644
--- a/contracts/governance/IGovernor.sol
+++ b/contracts/governance/IGovernor.sol
@@ -93,6 +93,12 @@ abstract contract IGovernor is IERC165 {
      * - `quorum=bravo` means that only For votes are counted towards quorum.
      * - `quorum=for,abstain` means that both For and Abstain votes are counted towards quorum.
      *
+     * If a counting module makes use of encoded `params`, it should  include this under a `params` key with a unique
+     * name that describes the behavior. For example:
+     *
+     * - `params=fractional` might refer to a scheme where votes are divided fractionally between for/against/abstain.
+     * - `params=erc721` might refer to a scheme where specific NFTs are delegated to vote.
+     *
      * NOTE: The string can be decoded by the standard
      * https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams[`URLSearchParams`]
      * JavaScript class.