Readability improvements ... apparently I still cant spell catastrophe.

contracts/staking/contracts/src/ReadOnlyProxy.sol

@@ -18,7 +18,6 @@
 
 pragma solidity ^0.5.9;
 
-import "./immutable/MixinConstants.sol";
 import "./immutable/MixinStorage.sol";
 import "./libs/LibProxy.sol";
 
@@ -35,8 +34,8 @@ contract ReadOnlyProxy is
     {
         address(this).proxyCall(
             LibProxy.RevertRule.NEVER_REVERT,
-            this.revertDelegateCall.selector,
-            false                                   // do not ignore this selector
+            this.revertDelegateCall.selector,       // custom egress selector
+            false                                   // do not ignore ingress selector
         );
     }
 
@@ -47,8 +46,8 @@ contract ReadOnlyProxy is
     {
         readOnlyProxyCallee.proxyCall(
             LibProxy.RevertRule.ALWAYS_REVERT,
-            bytes4(0),                              // no custom selector
-            true                                    // ignore this selector
+            bytes4(0),                              // no custom egress selector
+            true                                    // ignore ingress selector
         );
     }
 }

contracts/staking/contracts/src/StakingProxy.sol

@@ -49,8 +49,8 @@ contract StakingProxy is
     {
         stakingContract.proxyCall(
             LibProxy.RevertRule.REVERT_ON_ERROR,
-            bytes4(0),                              // no custom selector
-            false                                   // do not ignore this selector
+            bytes4(0),                              // no custom egress selector
+            false                                   // do not ignore ingress selector
         );
     }
 

contracts/staking/contracts/src/libs/LibProxy.sol

@@ -30,13 +30,16 @@ library LibProxy {
         NEVER_REVERT
     }
 
-    /// @dev Executes a read-only call to the staking contract, via `revertDelegateCall`.
-    ///      By routing through `revertDelegateCall` any state changes are reverted.
+    /// @dev Proxies incoming call to destination contract.
+    /// @param destination Address to call.
+    /// @param revertRule Describes scenarios in which this function reverts.
+    /// @param customEgressSelector Custom selector used to call destination contract.
+    /// @param ignoreIngressSelector Ignore the selector used to call into this contract.
     function proxyCall(
         address destination,
         RevertRule revertRule,
-        bytes4 customSelector,
-        bool ignoreSelector
+        bytes4 customEgressSelector,
+        bool ignoreIngressSelector
     )
         internal
     {
@@ -49,14 +52,14 @@ library LibProxy {
         assembly {
             // store selector of destination function
             let freeMemPtr := 0
-            if gt(customSelector, 0) {
-                mstore(0x0, customSelector)
+            if gt(customEgressSelector, 0) {
+                mstore(0x0, customEgressSelector)
                 freeMemPtr := add(freeMemPtr, 4)
             }
 
             // adjust the calldata offset, if we should ignore the selector
             let calldataOffset := 0
-            if gt(ignoreSelector, 0) {
+            if gt(ignoreIngressSelector, 0) {
                 calldataOffset := 4
             }
 

contracts/staking/contracts/src/libs/LibStakingRichErrors.sol

@@ -135,8 +135,8 @@ library LibStakingRichErrors {
         0xb7161acd;
 
     // bytes4(keccak256("ProxyDestinationCannotBeNil()"))
-    bytes4 internal constant PROXY_DESTINATION_CANNOT_BE_NIL =
-        0x01ecebea;
+    bytes internal constant PROXY_DESTINATION_CANNOT_BE_NIL =
+        hex"01ecebea";
 
     // solhint-disable func-name-mixedcase
     function MiscalculatedRewardsError(
@@ -515,9 +515,7 @@ library LibStakingRichErrors {
         pure
         returns (bytes memory)
     {
-        return abi.encodeWithSelector(
-            PROXY_DESTINATION_CANNOT_BE_NIL
-        );
+        return PROXY_DESTINATION_CANNOT_BE_NIL;
     }
 
 }

contracts/staking/test/catastrophe_test.ts

@@ -1,6 +1,6 @@
 import { ERC20ProxyContract, ERC20Wrapper } from '@0x/contracts-asset-proxy';
 import { DummyERC20TokenContract } from '@0x/contracts-erc20';
-import { blockchainTests, describe, expect, provider, web3Wrapper } from '@0x/contracts-test-utils';
+import { blockchainTests, describe, expect } from '@0x/contracts-test-utils';
 import { BigNumber } from '@0x/utils';
 import { LogWithDecodedArgs } from 'ethereum-types';
 import * as _ from 'lodash';
@@ -10,7 +10,7 @@ import { StakingProxyReadOnlyModeSetEventArgs } from '../src';
 import { StakingWrapper } from './utils/staking_wrapper';
 
 // tslint:disable:no-unnecessary-type-assertion
-blockchainTests.resets('Catastrophy Tests', () => {
+blockchainTests.resets('Catastrophe Tests', env => {
     // constants
     const ZRX_TOKEN_DECIMALS = new BigNumber(18);
     const ZERO = new BigNumber(0);
@@ -26,17 +26,17 @@ blockchainTests.resets('Catastrophy Tests', () => {
     // tests
     before(async () => {
         // create accounts
-        accounts = await web3Wrapper.getAvailableAddressesAsync();
+        accounts = await env.web3Wrapper.getAvailableAddressesAsync();
         owner = accounts[0];
         actors = accounts.slice(2, 5);
         // deploy erc20 proxy
-        erc20Wrapper = new ERC20Wrapper(provider, accounts, owner);
+        erc20Wrapper = new ERC20Wrapper(env.provider, accounts, owner);
         erc20ProxyContract = await erc20Wrapper.deployProxyAsync();
         // deploy zrx token
         [zrxTokenContract] = await erc20Wrapper.deployDummyTokensAsync(1, ZRX_TOKEN_DECIMALS);
         await erc20Wrapper.setBalancesAndAllowancesAsync();
         // deploy staking contracts
-        stakingWrapper = new StakingWrapper(provider, owner, erc20ProxyContract, zrxTokenContract, accounts);
+        stakingWrapper = new StakingWrapper(env.provider, owner, erc20ProxyContract, zrxTokenContract, accounts);
         await stakingWrapper.deployAndConfigureContractsAsync();
     });