From ca330907930b52ffc590b2a220831739a5c7f595 Mon Sep 17 00:00:00 2001
From: Lawrence Forman <lawrence@0xproject.com>
Date: Fri, 9 Aug 2019 21:23:57 -0400
Subject: [PATCH] `@0x/contracts-exchange`: Add comments to
 `LEGACY_WALLET_MAGIC_VALUE` constant in `TestValidatorWallet.sol`.
 `@0x/contracts-exchange`: Remove references to `LibExchangeSelectors` in the
 Exchange.

---
 contracts/exchange/contracts/src/MixinExchangeCore.sol     | 2 --
 contracts/exchange/contracts/src/MixinWrapperFunctions.sol | 1 -
 contracts/exchange/contracts/test/TestValidatorWallet.sol  | 2 ++
 contracts/exchange/contracts/test/TestWrapperFunctions.sol | 1 +
 4 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/contracts/exchange/contracts/src/MixinExchangeCore.sol b/contracts/exchange/contracts/src/MixinExchangeCore.sol
index 844419ec70..554390f40d 100644
--- a/contracts/exchange/contracts/src/MixinExchangeCore.sol
+++ b/contracts/exchange/contracts/src/MixinExchangeCore.sol
@@ -20,7 +20,6 @@ pragma experimental ABIEncoderV2;
 
 import "@0x/contracts-utils/contracts/src/LibBytes.sol";
 import "@0x/contracts-utils/contracts/src/LibRichErrors.sol";
-import "@0x/contracts-exchange-libs/contracts/src/LibExchangeSelectors.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibFillResults.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibMath.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibOrder.sol";
@@ -34,7 +33,6 @@ import "./MixinSignatureValidator.sol";
 contract MixinExchangeCore is
     IExchangeCore,
     IExchangeRichErrors,
-    LibExchangeSelectors,
     LibMath,
     LibFillResults,
     MixinAssetProxyDispatcher,
diff --git a/contracts/exchange/contracts/src/MixinWrapperFunctions.sol b/contracts/exchange/contracts/src/MixinWrapperFunctions.sol
index 07d57dd40a..0d76f2146d 100644
--- a/contracts/exchange/contracts/src/MixinWrapperFunctions.sol
+++ b/contracts/exchange/contracts/src/MixinWrapperFunctions.sol
@@ -21,7 +21,6 @@ pragma experimental ABIEncoderV2;
 
 import "@0x/contracts-utils/contracts/src/ReentrancyGuard.sol";
 import "@0x/contracts-utils/contracts/src/LibRichErrors.sol";
-import "@0x/contracts-exchange-libs/contracts/src/LibExchangeSelectors.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibMath.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibOrder.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibFillResults.sol";
diff --git a/contracts/exchange/contracts/test/TestValidatorWallet.sol b/contracts/exchange/contracts/test/TestValidatorWallet.sol
index 40abbbc396..aa7ef503f7 100644
--- a/contracts/exchange/contracts/test/TestValidatorWallet.sol
+++ b/contracts/exchange/contracts/test/TestValidatorWallet.sol
@@ -45,6 +45,8 @@ contract TestValidatorWallet is
 {
     using LibBytes for bytes;
 
+    // Magic bytes to be returned by `Wallet` signature type validators.
+    // bytes4(keccak256("isValidWalletSignature(bytes32,address,bytes)"))
     bytes4 private constant LEGACY_WALLET_MAGIC_VALUE = 0xb0671381;
 
     /// @dev Revert reason for `Revert` `ValidatorAction`.
diff --git a/contracts/exchange/contracts/test/TestWrapperFunctions.sol b/contracts/exchange/contracts/test/TestWrapperFunctions.sol
index 5786dda94b..f360f641a0 100644
--- a/contracts/exchange/contracts/test/TestWrapperFunctions.sol
+++ b/contracts/exchange/contracts/test/TestWrapperFunctions.sol
@@ -46,6 +46,7 @@ contract TestWrapperFunctions is
     // solhint-disable no-empty-blocks
     constructor ()
         public
+        // Initialize the exchange with a fixed chainId ("test" in hex).
         Exchange(0x74657374)
     {}