refactor: consolidated ALPHA_DIVISOR and ONE_BASIS_POINTS

Author: jaybuidl

contracts/src/arbitration/KlerosCoreBase.sol

@@ -88,7 +88,6 @@ abstract contract KlerosCoreBase is IArbitratorV2, Initializable, UUPSProxiable
     // *             Storage               * //
     // ************************************* //
 
-    uint256 private constant ALPHA_DIVISOR = 1e4; // The number to divide `Court.alpha` by.
     uint256 private constant NON_PAYABLE_AMOUNT = (2 ** 256 - 2) / 2; // An amount higher than the supply of ETH.
 
     address public governor; // The governor of the contract.
@@ -775,13 +774,13 @@ abstract contract KlerosCoreBase is IArbitratorV2, Initializable, UUPSProxiable
             _params.feePerJurorInRound,
             _params.pnkAtStakePerJurorInRound
         );
-        if (degreeOfCoherence > ALPHA_DIVISOR) {
+        if (degreeOfCoherence > ONE_BASIS_POINT) {
             // Make sure the degree doesn't exceed 1, though it should be ensured by the dispute kit.
-            degreeOfCoherence = ALPHA_DIVISOR;
+            degreeOfCoherence = ONE_BASIS_POINT;
         }
 
         // Fully coherent jurors won't be penalized.
-        uint256 penalty = (round.pnkAtStakePerJuror * (ALPHA_DIVISOR - degreeOfCoherence)) / ALPHA_DIVISOR;
+        uint256 penalty = (round.pnkAtStakePerJuror * (ONE_BASIS_POINT - degreeOfCoherence)) / ONE_BASIS_POINT;
 
         // Unlock the PNKs affected by the penalty
         address account = round.drawnJurors[_params.repartition];
@@ -835,8 +834,8 @@ abstract contract KlerosCoreBase is IArbitratorV2, Initializable, UUPSProxiable
         );
 
         // Make sure the degree doesn't exceed 1, though it should be ensured by the dispute kit.
-        if (degreeOfCoherence > ALPHA_DIVISOR) {
-            degreeOfCoherence = ALPHA_DIVISOR;
+        if (degreeOfCoherence > ONE_BASIS_POINT) {
+            degreeOfCoherence = ONE_BASIS_POINT;
         }
 
         address account = round.drawnJurors[_params.repartition % _params.numberOfVotesInRound];
@@ -1062,15 +1061,15 @@ abstract contract KlerosCoreBase is IArbitratorV2, Initializable, UUPSProxiable
     /// @param _degreeOfCoherence The degree of coherence in basis points.
     /// @return The amount after applying the degree of coherence.
     function _applyCoherence(uint256 _amount, uint256 _degreeOfCoherence) internal pure returns (uint256) {
-        return (_amount * _degreeOfCoherence) / ALPHA_DIVISOR;
+        return (_amount * _degreeOfCoherence) / ONE_BASIS_POINT;
     }
 
     /// @dev Calculates PNK at stake per juror based on court parameters
     /// @param _minStake The minimum stake for the court.
     /// @param _alpha The alpha parameter for the court in basis points.
     /// @return The amount of PNK at stake per juror.
     function _calculatePnkAtStake(uint256 _minStake, uint256 _alpha) internal pure returns (uint256) {
-        return (_minStake * _alpha) / ALPHA_DIVISOR;
+        return (_minStake * _alpha) / ONE_BASIS_POINT;
     }
 
     /// @dev Toggles the dispute kit support for a given court.

contracts/src/arbitration/dispute-kits/DisputeKitClassicBase.sol

@@ -6,6 +6,7 @@ import {KlerosCore, KlerosCoreBase, IDisputeKit, ISortitionModule} from "../Kler
 import {Initializable} from "../../proxy/Initializable.sol";
 import {UUPSProxiable} from "../../proxy/UUPSProxiable.sol";
 import {SafeSend} from "../../libraries/SafeSend.sol";
+import {ONE_BASIS_POINT} from "../../libraries/Constants.sol";
 
 /// @title DisputeKitClassicBase
 /// Abstract Dispute kit classic implementation of the Kleros v1 features including:
@@ -57,7 +58,6 @@ abstract contract DisputeKitClassicBase is IDisputeKit, Initializable, UUPSProxi
     uint256 public constant WINNER_STAKE_MULTIPLIER = 10000; // Multiplier of the appeal cost that the winner has to pay as fee stake for a round in basis points. Default is 1x of appeal fee.
     uint256 public constant LOSER_STAKE_MULTIPLIER = 20000; // Multiplier of the appeal cost that the loser has to pay as fee stake for a round in basis points. Default is 2x of appeal fee.
     uint256 public constant LOSER_APPEAL_PERIOD_MULTIPLIER = 5000; // Multiplier of the appeal period for the choice that wasn't voted for in the previous round, in basis points. Default is 1/2 of original appeal period.
-    uint256 public constant ONE_BASIS_POINT = 10000; // One basis point, for scaling.
 
     address public governor; // The governor of the contract.
     KlerosCore public core; // The Kleros Core arbitrator

contracts/src/libraries/Constants.sol

@@ -20,6 +20,9 @@ uint256 constant DEFAULT_K = 6; // Default number of children per node.
 uint256 constant DEFAULT_NB_OF_JURORS = 3; // The default number of jurors in a dispute.
 IERC20 constant NATIVE_CURRENCY = IERC20(address(0)); // The native currency, such as ETH on Arbitrum, Optimism and Ethereum L1.
 
+// Units
+uint256 constant ONE_BASIS_POINT = 10000;
+
 enum OnError {
     Revert,
     Return