Merge pull request #23 from ampleforth/elastic-interface

Porting recent changes from base-chain codebase

Author: aalavandhan

.eslintrc.js

@@ -101,6 +101,8 @@ module.exports = {
           'Utf8Bytes',
           'keccak256',
           'Sighash',
+          'hre',
+          'ecsign',
 
           // shorthand
           'eth',
@@ -175,6 +177,7 @@ module.exports = {
           'rebasing',
           'depositer',
           'coinmarketcap',
+          'nonces',
 
           // names
           'nithin',

contracts/_interfaces/IAmpleforthPolicy.sol

@@ -1,14 +1,8 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 pragma solidity 0.6.12;
 
-interface IXCAmple {
-    function globalAMPLSupply() external returns (uint256);
+import "uFragments/contracts/interfaces/IAMPL.sol";
 
-    function mint(address who, uint256 value) external;
-
-    function burn(address who, uint256 value) external;
-
-    function rebase(uint256 globalAmpleforthEpoch_, uint256 globalAMPLSupply_)
-        external
-        returns (uint256);
+interface IXCAmple is IAMPL {
+    function globalAMPLSupply() external view returns (uint256);
 }

contracts/_interfaces/IXCAmple.sol

@@ -2,11 +2,11 @@
 pragma solidity 0.6.12;
 
 interface IXCAmpleController {
-    function globalAmpleforthEpoch() external returns (uint256);
+    function rebase() external;
 
-    function mint(address recipient, uint256 xcAmplAmount) external;
+    function lastRebaseTimestampSec() external view returns (uint256);
 
-    function burn(address depositor, uint256 xcAmplAmount) external;
+    function globalAmpleforthEpoch() external view returns (uint256);
 
-    function reportRebase(uint256 nextGlobalAmpleforthEpoch, uint256 nextGlobalAMPLSupply) external;
+    function globalAmpleforthEpochAndAMPLSupply() external view returns (uint256, uint256);
 }

contracts/_interfaces/IXCAmpleController.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+pragma solidity 0.6.12;
+
+interface IXCAmpleControllerGateway {
+    function nextGlobalAmpleforthEpoch() external view returns (uint256);
+
+    function nextGlobalAMPLSupply() external view returns (uint256);
+
+    function mint(address recipient, uint256 xcAmplAmount) external;
+
+    function burn(address depositor, uint256 xcAmplAmount) external;
+
+    function reportRebase(uint256 nextGlobalAmpleforthEpoch_, uint256 nextGlobalAMPLSupply_)
+        external;
+}

contracts/_interfaces/IXCAmpleControllerGateway.sol

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+pragma solidity 0.6.12;
+
+interface IXCAmpleSupplyPolicy {
+    function rebase(uint256 globalAmpleforthEpoch_, uint256 globalAMPLSupply_)
+        external
+        returns (uint256);
+
+    function mint(address who, uint256 value) external;
+
+    function burn(address who, uint256 value) external;
+}

contracts/_interfaces/IXCAmpleSupplyPolicy.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 pragma solidity 0.6.12;
 
-contract MockAmplPolicy {
+contract MockAmpleforth {
     uint256 public epoch;
 
     function updateEpoch(uint256 epoch_) external {

contracts/_mocks/MockAmplPolicy.sol renamed to contracts/_mocks/MockAmpleforth.sol

@@ -18,6 +18,7 @@ contract MockXCAmple {
     }
 
     function rebase(uint256 globalEpoch, uint256 globalAMPLSupply_) external returns (uint256) {
+        globalAMPLSupply = globalAMPLSupply_;
         emit Rebase(globalEpoch, globalAMPLSupply_);
     }
 

contracts/_mocks/MockXCAmple.sol

@@ -5,7 +5,7 @@ import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
 import {SafeMath} from "@openzeppelin/contracts/math/SafeMath.sol";
 
 import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
-import {IAmpleforthPolicy} from "../../_interfaces/IAmpleforthPolicy.sol";
+import {IAmpleforth} from "uFragments/contracts/interfaces/IAmpleforth.sol";
 import {ITokenVault} from "../../_interfaces/ITokenVault.sol";
 import {IBridgeGateway} from "../../_interfaces/IBridgeGateway.sol";
 
@@ -51,9 +51,8 @@ contract AMPLChainBridgeGateway is IBridgeGateway, Ownable {
     function validateRebaseReport(uint256 globalAmpleforthEpoch, uint256 globalAMPLSupply)
         external
         onlyOwner
-        returns (bool)
     {
-        uint256 recordedGlobalAmpleforthEpoch = IAmpleforthPolicy(policy).epoch();
+        uint256 recordedGlobalAmpleforthEpoch = IAmpleforth(policy).epoch();
         uint256 recordedGlobalAMPLSupply = IERC20(ampl).totalSupply();
 
         require(
@@ -66,8 +65,6 @@ contract AMPLChainBridgeGateway is IBridgeGateway, Ownable {
         );
 
         emit XCRebaseReportOut(globalAmpleforthEpoch, globalAMPLSupply);
-
-        return true;
     }
 
     /**
@@ -83,7 +80,7 @@ contract AMPLChainBridgeGateway is IBridgeGateway, Ownable {
         address recipientAddressInTargetChain,
         uint256 amount,
         uint256 globalAMPLSupply
-    ) external onlyOwner returns (bool) {
+    ) external onlyOwner {
         uint256 recordedGlobalAMPLSupply = IERC20(ampl).totalSupply();
 
         require(
@@ -94,8 +91,6 @@ contract AMPLChainBridgeGateway is IBridgeGateway, Ownable {
         ITokenVault(vault).lock(ampl, sender, amount);
 
         emit XCTransferOut(sender, amount, recordedGlobalAMPLSupply);
-
-        return true;
     }
 
     /**
@@ -111,15 +106,13 @@ contract AMPLChainBridgeGateway is IBridgeGateway, Ownable {
         address recipient,
         uint256 amount,
         uint256 globalAMPLSupply
-    ) external onlyOwner returns (bool) {
+    ) external onlyOwner {
         uint256 recordedGlobalAMPLSupply = IERC20(ampl).totalSupply();
         uint256 unlockAmount = amount.mul(recordedGlobalAMPLSupply).div(globalAMPLSupply);
 
         emit XCTransferIn(recipient, globalAMPLSupply, unlockAmount, recordedGlobalAMPLSupply);
 
         ITokenVault(vault).unlock(ampl, recipient, unlockAmount);
-
-        return true;
     }
 
     constructor(

contracts/base-chain/bridge-gateways/AMPLChainBridgeGateway.sol

@@ -6,6 +6,7 @@ import {SafeMath} from "@openzeppelin/contracts/math/SafeMath.sol";
 
 import {IBridgeGateway} from "../../_interfaces/IBridgeGateway.sol";
 import {IXCAmpleController} from "../../_interfaces/IXCAmpleController.sol";
+import {IXCAmpleControllerGateway} from "../../_interfaces/IXCAmpleControllerGateway.sol";
 import {IXCAmple} from "../../_interfaces/IXCAmple.sol";
 
 /**
@@ -45,7 +46,6 @@ contract ChainBridgeXCAmpleGateway is IBridgeGateway, Ownable {
     function reportRebase(uint256 globalAmpleforthEpoch, uint256 globalAMPLSupply)
         external
         onlyOwner
-        returns (bool)
     {
         uint256 recordedGlobalAmpleforthEpoch = IXCAmpleController(xcController)
             .globalAmpleforthEpoch();
@@ -59,9 +59,10 @@ contract ChainBridgeXCAmpleGateway is IBridgeGateway, Ownable {
             recordedGlobalAMPLSupply
         );
 
-        IXCAmpleController(xcController).reportRebase(globalAmpleforthEpoch, globalAMPLSupply);
-
-        return true;
+        IXCAmpleControllerGateway(xcController).reportRebase(
+            globalAmpleforthEpoch,
+            globalAMPLSupply
+        );
     }
 
     /**
@@ -78,15 +79,13 @@ contract ChainBridgeXCAmpleGateway is IBridgeGateway, Ownable {
         address recipient,
         uint256 amount,
         uint256 globalAMPLSupply
-    ) external onlyOwner returns (bool) {
+    ) external onlyOwner {
         uint256 recordedGlobalAMPLSupply = IXCAmple(xcAmple).globalAMPLSupply();
         uint256 mintAmount = amount.mul(recordedGlobalAMPLSupply).div(globalAMPLSupply);
 
         emit XCTransferIn(recipient, globalAMPLSupply, mintAmount, recordedGlobalAMPLSupply);
 
-        IXCAmpleController(xcController).mint(recipient, mintAmount);
-
-        return true;
+        IXCAmpleControllerGateway(xcController).mint(recipient, mintAmount);
     }
 
     /**
@@ -101,18 +100,16 @@ contract ChainBridgeXCAmpleGateway is IBridgeGateway, Ownable {
         address recipientAddressInTargetChain,
         uint256 amount,
         uint256 globalAMPLSupply
-    ) external onlyOwner returns (bool) {
+    ) external onlyOwner {
         uint256 recordedGlobalAMPLSupply = IXCAmple(xcAmple).globalAMPLSupply();
         require(
             globalAMPLSupply == recordedGlobalAMPLSupply,
             "ChainBridgeXCAmpleGateway: total supply not consistent"
         );
 
-        IXCAmpleController(xcController).burn(sender, amount);
+        IXCAmpleControllerGateway(xcController).burn(sender, amount);
 
         emit XCTransferOut(sender, amount, recordedGlobalAMPLSupply);
-
-        return true;
     }
 
     constructor(