Make contracts/exchange-libs/.../LibEIP712.sol stateless

contracts/coordinator/contracts/src/Coordinator.sol

@@ -19,7 +19,6 @@
 pragma solidity ^0.5.5;
 pragma experimental "ABIEncoderV2";
 
-import "@0x/contracts-exchange-libs/contracts/src/LibEIP712.sol";
 import "./libs/LibConstants.sol";
 import "./MixinSignatureValidator.sol";
 import "./MixinCoordinatorApprovalVerifier.sol";
@@ -29,16 +28,15 @@ import "./MixinCoordinatorCore.sol";
 // solhint-disable no-empty-blocks
 contract Coordinator is
     LibConstants,
-    LibEIP712,
     MixinSignatureValidator,
     MixinCoordinatorApprovalVerifier,
     MixinCoordinatorCore
 {
-    /// @param _exchange Address of the 0x Exchange contract.
+    /// @param exchange Address of the 0x Exchange contract.
-    /// @param _chainId Chain ID of the network this contract is deployed on.
+    /// @param chainId Chain ID of the network this contract is deployed on.
-    constructor (address _exchange, uint256 _chainId)
+    constructor (address exchange, uint256 chainId)
         public
-        LibConstants(_exchange)
+        LibConstants(exchange)
-        LibEIP712(_chainId)
+        LibEIP712Domain(chainId)
     {}
 }

contracts/coordinator/contracts/src/libs/LibConstants.sol

@@ -27,10 +27,10 @@ contract LibConstants {
     // The 0x Exchange contract.
     ITransactions internal EXCHANGE;
 
-    /// @param _exchange Address of the 0x Exchange contract.
+    /// @param exchange Address of the 0x Exchange contract.
-    constructor (address _exchange)
+    constructor (address exchange)
         public
     {
-        EXCHANGE = ITransactions(_exchange);
+        EXCHANGE = ITransactions(exchange);
     }
 }

contracts/coordinator/contracts/src/libs/LibEIP712Domain.sol

@@ -42,17 +42,20 @@ contract LibEIP712Domain is
     // Hash of the EIP712 Domain Separator data for the Exchange
     bytes32 public EIP712_EXCHANGE_DOMAIN_HASH;
 
-    constructor ()
+    /// @param chainId Chain ID of the network this contract is deployed on.
+    constructor (uint256 chainId)
         public
     {
         EIP712_COORDINATOR_DOMAIN_HASH = hashEIP712Domain(
             EIP712_COORDINATOR_DOMAIN_NAME,
             EIP712_COORDINATOR_DOMAIN_VERSION,
+            chainId,
             address(this)
         );
         EIP712_EXCHANGE_DOMAIN_HASH = hashEIP712Domain(
             EIP712_EXCHANGE_DOMAIN_NAME,
             EIP712_EXCHANGE_DOMAIN_VERSION,
+            chainId,
             address(EXCHANGE)
         );
     }

contracts/exchange-libs/contracts/src/LibEIP712.sol

@@ -27,30 +27,20 @@ contract LibEIP712 {
         "string name,",
         "string version,",
         "uint256 chainId,",
-        "address verifyingContract",
+        "address verifyingContractAddress",
         ")"
     ));
 
-    // Chain ID of the network this contract is deployed on.
-    // solhint-disable-next-line var-name-mixedcase
-    uint256 internal CHAIN_ID;
-
-    /// @param chainId Chain ID of the network this contract is deployed on.
-    constructor (uint256 chainId)
-        public
-    {
-        CHAIN_ID = chainId;
-    }
-
     /// @dev Calculates a EIP712 domain separator.
     /// @param name The EIP712 domain name.
     /// @param version The EIP712 domain version.
-    /// @param verifyingContract The EIP712 verifying contract.
+    /// @param verifyingContractAddress The EIP712 verifying contract.
     /// @return EIP712 domain separator.
     function hashEIP712Domain(
         string memory name,
         string memory version,
-        address verifyingContract
+        uint256 chainId,
+        address verifyingContractAddress
     )
         internal
         view
@@ -60,8 +50,8 @@ contract LibEIP712 {
             EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH,
             keccak256(bytes(name)),
             keccak256(bytes(version)),
-            CHAIN_ID,
+            chainId,
-            uint256(verifyingContract)
+            uint256(verifyingContractAddress)
         ));
     }
 

contracts/exchange-libs/contracts/src/LibEIP712ExchangeDomain.sol

@@ -30,12 +30,14 @@ contract LibEIP712ExchangeDomain is
     // solhint-disable-next-line var-name-mixedcase
     bytes32 internal EIP712_EXCHANGE_DOMAIN_HASH;
 
-    constructor ()
+    /// @param chainId Chain ID of the network this contract is deployed on.
+    constructor (uint256 chainId)
         public
     {
         EIP712_EXCHANGE_DOMAIN_HASH = hashEIP712Domain(
             EIP712_EXCHANGE_DOMAIN_NAME,
             EIP712_EXCHANGE_DOMAIN_VERSION,
+            chainId,
             address(this)
         );
     }

contracts/exchange-libs/contracts/test/TestLibs.sol

@@ -36,7 +36,7 @@ contract TestLibs is
 {
     constructor (uint256 chainId)
         public
-        LibEIP712(chainId)
+        LibEIP712ExchangeDomain(chainId)
     {}
 
     function publicAbiEncodeFillOrder(

contracts/exchange/contracts/src/Exchange.sol

@@ -20,7 +20,6 @@ pragma solidity ^0.5.5;
 pragma experimental ABIEncoderV2;
 
 import "@0x/contracts-exchange-libs/contracts/src/LibConstants.sol";
-import "@0x/contracts-exchange-libs/contracts/src/LibEIP712.sol";
 import "./MixinExchangeCore.sol";
 import "./MixinSignatureValidator.sol";
 import "./MixinWrapperFunctions.sol";
@@ -41,12 +40,12 @@ contract Exchange is
     string constant public VERSION = "3.0.0";
 
     /// @dev Mixins are instantiated in the order they are inherited
-    /// @param _zrxAssetData Asset data for ZRX token. Used for fee transfers.
+    /// @param zrxAssetData Asset data for ZRX token. Used for fee transfers.
-    /// @param _chainId Chain ID of the network this contract is deployed on.
+    /// @param chainId Chain ID of the network this contract is deployed on.
-    constructor (bytes memory _zrxAssetData, uint256 _chainId)
+    constructor (bytes memory zrxAssetData, uint256 chainId)
         public
-        LibConstants(_zrxAssetData) // @TODO: Remove _zrxAssetData when we deploy.
+        LibConstants(zrxAssetData) // @TODO: Remove zrxAssetData when we deploy.
-        LibEIP712(_chainId)
+        LibEIP712ExchangeDomain(chainId)
         MixinExchangeCore()
         MixinMatchOrders()
         MixinSignatureValidator()

contracts/exchange/contracts/test/TestSignatureValidator.sol

@@ -32,7 +32,7 @@ contract TestSignatureValidator is
     // solhint-disable no-empty-blocks
     constructor (uint256 chainId)
         public
-        LibEIP712(chainId)
+        LibEIP712ExchangeDomain(chainId)
     {}
 
     function publicIsValidSignature(