make governor into interface

contracts/governance/Governor.sol

@@ -826,4 +826,10 @@ abstract contract Governor is Context, ERC165, EIP712, Nonces, IGovernor, IERC72
             }
         }
     }
+
+    function clock() public virtual view returns (uint48);
+    function CLOCK_MODE() public virtual view returns (string memory);
+    function votingDelay() public virtual view returns (uint256);
+    function votingPeriod() public virtual view returns (uint256);
+    function quorum(uint256 timepoint) public virtual view returns (uint256);
 }

contracts/governance/IGovernor.sol

@@ -9,7 +9,7 @@ import {IERC6372} from "../interfaces/IERC6372.sol";
 /**
  * @dev Interface of the {Governor} core.
  */
-abstract contract IGovernor is IERC165, IERC6372 {
+interface IGovernor is IERC165, IERC6372 {
     enum ProposalState {
         Pending,
         Active,
@@ -160,26 +160,26 @@ abstract contract IGovernor is IERC165, IERC6372 {
      * @notice module:core
      * @dev Name of the governor instance (used in building the ERC712 domain separator).
      */
-    function name() public view virtual returns (string memory);
+    function name() external view returns (string memory);
 
     /**
      * @notice module:core
      * @dev Version of the governor instance (used in building the ERC712 domain separator). Default: "1"
      */
-    function version() public view virtual returns (string memory);
+    function version() external view returns (string memory);
 
     /**
      * @notice module:core
      * @dev See {IERC6372}
      */
-    function clock() public view virtual returns (uint48);
+    function clock() external view returns (uint48);
 
     /**
      * @notice module:core
      * @dev See EIP-6372.
      */
     // solhint-disable-next-line func-name-mixedcase
-    function CLOCK_MODE() public view virtual returns (string memory);
+    function CLOCK_MODE() external view returns (string memory);
 
     /**
      * @notice module:voting
@@ -204,7 +204,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
      * JavaScript class.
      */
     // solhint-disable-next-line func-name-mixedcase
-    function COUNTING_MODE() public view virtual returns (string memory);
+    function COUNTING_MODE() external view returns (string memory);
 
     /**
      * @notice module:core
@@ -215,13 +215,13 @@ abstract contract IGovernor is IERC165, IERC6372 {
         uint256[] memory values,
         bytes[] memory calldatas,
         bytes32 descriptionHash
-    ) public pure virtual returns (uint256);
+    ) external pure returns (uint256);
 
     /**
      * @notice module:core
      * @dev Current state of a proposal, following Compound's convention
      */
-    function state(uint256 proposalId) public view virtual returns (ProposalState);
+    function state(uint256 proposalId) external view returns (ProposalState);
 
     /**
      * @notice module:core
@@ -235,28 +235,28 @@ abstract contract IGovernor is IERC165, IERC6372 {
      * snapshot is performed at the end of this block. Hence, voting for this proposal starts at the beginning of the
      * following block.
      */
-    function proposalSnapshot(uint256 proposalId) public view virtual returns (uint256);
+    function proposalSnapshot(uint256 proposalId) external view returns (uint256);
 
     /**
      * @notice module:core
      * @dev Timepoint at which votes close. If using block number, votes close at the end of this block, so it is
      * possible to cast a vote during this block.
      */
-    function proposalDeadline(uint256 proposalId) public view virtual returns (uint256);
+    function proposalDeadline(uint256 proposalId) external view returns (uint256);
 
     /**
      * @notice module:core
      * @dev The account that created a proposal.
      */
-    function proposalProposer(uint256 proposalId) public view virtual returns (address);
+    function proposalProposer(uint256 proposalId) external view returns (address);
 
     /**
      * @notice module:core
      * @dev The time when a queued proposal becomes executable ("ETA"). Unlike {proposalSnapshot} and
      * {proposalDeadline}, this doesn't use the governor clock, and instead relies on the executor's clock which may be
      * different. In most cases this will be a timestamp.
      */
-    function proposalEta(uint256 proposalId) public view virtual returns (uint256);
+    function proposalEta(uint256 proposalId) external view returns (uint256);
 
     /**
      * @notice module:user-config
@@ -269,7 +269,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
      * NOTE: While this interface returns a uint256, timepoints are stored as uint48 following the ERC-6372 clock type.
      * Consequently this value must fit in a uint48 (when added to the current clock). See {IERC6372-clock}.
      */
-    function votingDelay() public view virtual returns (uint256);
+    function votingDelay() external view returns (uint256);
 
     /**
      * @notice module:user-config
@@ -283,7 +283,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
      * proposals that have already been submitted. The type used to save it is a uint32. Consequently, while this
      * interface returns a uint256, the value it returns should fit in a uint32.
      */
-    function votingPeriod() public view virtual returns (uint256);
+    function votingPeriod() external view returns (uint256);
 
     /**
      * @notice module:user-config
@@ -292,7 +292,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
      * NOTE: The `timepoint` parameter corresponds to the snapshot used for counting vote. This allows to scale the
      * quorum depending on values such as the totalSupply of a token at this timepoint (see {ERC20Votes}).
      */
-    function quorum(uint256 timepoint) public view virtual returns (uint256);
+    function quorum(uint256 timepoint) external view returns (uint256);
 
     /**
      * @notice module:reputation
@@ -301,7 +301,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
      * Note: this can be implemented in a number of ways, for example by reading the delegated balance from one (or
      * multiple), {ERC20Votes} tokens.
      */
-    function getVotes(address account, uint256 timepoint) public view virtual returns (uint256);
+    function getVotes(address account, uint256 timepoint) external view returns (uint256);
 
     /**
      * @notice module:reputation
@@ -311,13 +311,13 @@ abstract contract IGovernor is IERC165, IERC6372 {
         address account,
         uint256 timepoint,
         bytes memory params
-    ) public view virtual returns (uint256);
+    ) external view returns (uint256);
 
     /**
      * @notice module:voting
      * @dev Returns whether `account` has cast a vote on `proposalId`.
      */
-    function hasVoted(uint256 proposalId, address account) public view virtual returns (bool);
+    function hasVoted(uint256 proposalId, address account) external view returns (bool);
 
     /**
      * @dev Create a new proposal. Vote start after a delay specified by {IGovernor-votingDelay} and lasts for a
@@ -330,7 +330,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
         uint256[] memory values,
         bytes[] memory calldatas,
         string memory description
-    ) public virtual returns (uint256 proposalId);
+    ) external returns (uint256 proposalId);
 
     /**
      * @dev Queue a proposal. Some governors require this step to be performed before execution can happen. If queuing
@@ -344,7 +344,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
         uint256[] memory values,
         bytes[] memory calldatas,
         bytes32 descriptionHash
-    ) public virtual returns (uint256 proposalId);
+    ) external returns (uint256 proposalId);
 
     /**
      * @dev Execute a successful proposal. This requires the quorum to be reached, the vote to be successful, and the
@@ -360,7 +360,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
         uint256[] memory values,
         bytes[] memory calldatas,
         bytes32 descriptionHash
-    ) public payable virtual returns (uint256 proposalId);
+    ) external payable returns (uint256 proposalId);
 
     /**
      * @dev Cancel a proposal. A proposal is cancellable by the proposer, but only while it is Pending state, i.e.
@@ -373,14 +373,14 @@ abstract contract IGovernor is IERC165, IERC6372 {
         uint256[] memory values,
         bytes[] memory calldatas,
         bytes32 descriptionHash
-    ) public virtual returns (uint256 proposalId);
+    ) external returns (uint256 proposalId);
 
     /**
      * @dev Cast a vote
      *
      * Emits a {VoteCast} event.
      */
-    function castVote(uint256 proposalId, uint8 support) public virtual returns (uint256 balance);
+    function castVote(uint256 proposalId, uint8 support) external returns (uint256 balance);
 
     /**
      * @dev Cast a vote with a reason
@@ -391,7 +391,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
         uint256 proposalId,
         uint8 support,
         string calldata reason
-    ) public virtual returns (uint256 balance);
+    ) external returns (uint256 balance);
 
     /**
      * @dev Cast a vote with a reason and additional encoded parameters
@@ -403,7 +403,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
         uint8 support,
         string calldata reason,
         bytes memory params
-    ) public virtual returns (uint256 balance);
+    ) external returns (uint256 balance);
 
     /**
      * @dev Cast a vote using the voter's signature, including ERC-1271 signature support.
@@ -415,7 +415,7 @@ abstract contract IGovernor is IERC165, IERC6372 {
         uint8 support,
         address voter,
         bytes memory signature
-    ) public virtual returns (uint256 balance);
+    ) external returns (uint256 balance);
 
     /**
      * @dev Cast a vote with a reason and additional encoded parameters using the voter's signature,
@@ -430,5 +430,5 @@ abstract contract IGovernor is IERC165, IERC6372 {
         string calldata reason,
         bytes memory params,
         bytes memory signature
-    ) public virtual returns (uint256 balance);
+    ) external returns (uint256 balance);
 }

contracts/mocks/governance/GovernorStorageMock.sol

@@ -18,7 +18,7 @@ abstract contract GovernorStorageMock is
 {
     function quorum(
         uint256 blockNumber
-    ) public view override(IGovernor, GovernorVotesQuorumFraction) returns (uint256) {
+    ) public view override(Governor, GovernorVotesQuorumFraction) returns (uint256) {
         return super.quorum(blockNumber);
     }
 

contracts/mocks/governance/GovernorTimelockCompoundMock.sol

@@ -16,7 +16,7 @@ abstract contract GovernorTimelockCompoundMock is
 {
     function quorum(
         uint256 blockNumber
-    ) public view override(IGovernor, GovernorVotesQuorumFraction) returns (uint256) {
+    ) public view override(Governor, GovernorVotesQuorumFraction) returns (uint256) {
         return super.quorum(blockNumber);
     }
 

contracts/mocks/governance/GovernorTimelockControlMock.sol

@@ -16,7 +16,7 @@ abstract contract GovernorTimelockControlMock is
 {
     function quorum(
         uint256 blockNumber
-    ) public view override(IGovernor, GovernorVotesQuorumFraction) returns (uint256) {
+    ) public view override(Governor, GovernorVotesQuorumFraction) returns (uint256) {
         return super.quorum(blockNumber);
     }