feat(Arbitration): standard update

CHANGELOG.md

@@ -1,8 +1,15 @@
-## 0.1.0 (2021-11-11)
+## 0.1.0 (2021-11-30)
 
+- fix(Arbitrator): memory to calldata ([4770b1f](https://github.com/kleros/kleros-v2/commit/4770b1f))
+- fix(IArbitrator): appeals removed from the standard ([02c20ce](https://github.com/kleros/kleros-v2/commit/02c20ce))
+- fix(IArbitrator): interface simplification ([e81fb8b](https://github.com/kleros/kleros-v2/commit/e81fb8b))
+- fix(IArbitrator): replaced appealCost with fundingStatus ([f189dd9](https://github.com/kleros/kleros-v2/commit/f189dd9))
+- feat: modern toolchain setup and simple RNG smart contracts ([17f6a76](https://github.com/kleros/kleros-v2/commit/17f6a76))
+- feat(Arbitration): standard update ([ed930de](https://github.com/kleros/kleros-v2/commit/ed930de))
+- chore: added GitHub code scanning ([4a70475](https://github.com/kleros/kleros-v2/commit/4a70475))
+- chore: added the hardhat config for layer 2 networks, added hardhat-deploy and mocha ([a12ea0e](https://github.com/kleros/kleros-v2/commit/a12ea0e))
 - test: added a test for IncrementalNG ([65a996b](https://github.com/kleros/kleros-v2/commit/65a996b))
 - docs: initial commit ([23356e7](https://github.com/kleros/kleros-v2/commit/23356e7))
 - docs: license file added ([cb62d2c](https://github.com/kleros/kleros-v2/commit/cb62d2c))
 - docs: readme and spdx headers ([8a5b397](https://github.com/kleros/kleros-v2/commit/8a5b397))
 - docs: updated ([5b9a8f1](https://github.com/kleros/kleros-v2/commit/5b9a8f1))
-- feat: modern toolchain setup and simple RNG smart contracts ([17f6a76](https://github.com/kleros/kleros-v2/commit/17f6a76))

contracts/src/arbitration/ArbitrableExample.sol

@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8;
+
+import "./IArbitrable.sol";
+
+/**
+ *  @title ArbitrableExample
+ *  An example of the arbitrable contract which connects to the arbitator that implements IArbitrator interface.
+ */
+contract ArbitrableExample is IArbitrable {
+    struct DisputeStruct {
+        bool isRuled; // Whether the dispute has been ruled or not.
+        uint256 ruling; // Ruling given by the arbitrator.
+        uint256 numberOfRulingOptions; // The number of choices the arbitrator can give.
+    }
+
+    IArbitrator public immutable arbitrator; // Arbitrator is set in constructor and never changed.
+
+    mapping(uint256 => uint256) public externalIDtoLocalID; // Maps external (arbitrator side) dispute IDs to local dispute IDs.
+
+    DisputeStruct[] public disputes; // Stores the disputes' info. disputes[disputeID].
+
+    /** @dev Constructor
+     *  @param _arbitrator The arbitrator to rule on created disputes.
+     */
+    constructor(IArbitrator _arbitrator) {
+        arbitrator = _arbitrator;
+    }
+
+    /** @dev TRUSTED. Calls createDispute function of the specified arbitrator to create a dispute.
+        Note that we don’t need to check that msg.value is enough to pay arbitration fees as it’s the responsibility of the arbitrator contract.
+     *  @param _numberOfRulingOptions Number of ruling options. Must be greater than 1, otherwise there is nothing to choose from.
+     *  @param _arbitratorExtraData Extra data for the arbitrator.
+     *  @return disputeID Dispute id (on arbitrator side) of the dispute created.
+     */
+    function createDispute(uint256 _numberOfRulingOptions, bytes calldata _arbitratorExtraData)
+        external
+        payable
+        returns (uint256 disputeID)
+    {
+        require(_numberOfRulingOptions > 1, "Incorrect number of choices");
+
+        uint256 localDisputeID = disputes.length;
+        disputes.push(DisputeStruct({isRuled: false, ruling: 0, numberOfRulingOptions: _numberOfRulingOptions}));
+
+        disputeID = arbitrator.createDispute{value: msg.value}(_numberOfRulingOptions, _arbitratorExtraData);
+
+        externalIDtoLocalID[disputeID] = localDisputeID;
+    }
+
+    /** @dev To be called by the arbitrator of the dispute, to declare the winning ruling.
+     *  @param _externalDisputeID ID of the dispute in arbitrator contract.
+     *  @param _ruling The ruling choice of the arbitration.
+     */
+    function rule(uint256 _externalDisputeID, uint256 _ruling) external override {
+        uint256 localDisputeID = externalIDtoLocalID[_externalDisputeID];
+        DisputeStruct storage dispute = disputes[localDisputeID];
+        require(msg.sender == address(arbitrator), "Only the arbitrator can execute this.");
+        require(_ruling <= dispute.numberOfRulingOptions, "Invalid ruling.");
+        require(dispute.isRuled == false, "This dispute has been ruled already.");
+
+        dispute.isRuled = true;
+        dispute.ruling = _ruling;
+
+        emit Ruling(IArbitrator(msg.sender), _externalDisputeID, dispute.ruling);
+    }
+}