@0x:contracts-staking Added unit tests for LibProxy

contracts/staking/contracts/test/TestLibProxy.sol

@@ -31,27 +31,44 @@ pragma experimental ABIEncoderV2;
 import "../src/libs/LibProxy.sol";
 
 
+// solhint-disable payable-fallback
 contract TestLibProxy {
 
     using LibProxy for address;
 
+    // The arguments of `proxyCall()`.
+    struct ProxyCallArguments {
+        address destination;
+        LibProxy.RevertRule revertRule;
+        bytes4 customEgressSelector;
+        bool ignoreIngressSelector;
+    }
+
+    // The current arguments that should be passed in the call to `proxyCall()`. This
+    // state allows us to send in the exact calldata that should be sent to `proxyCall()`
+    // while still being able to test any combination of inputs to `proxyCall()`.
+    ProxyCallArguments internal proxyCallArgs;
+
     /// @dev Exposes the `proxyCall()` library function from LibProxy.
-    /// @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 externalProxyCall(
-        address destination,
-        LibProxy.RevertRule revertRule,
-        bytes4 customEgressSelector,
-        bool ignoreIngressSelector
-    )
+    function ()
         external
     {
-        destination.proxyCall(
-            revertRule,
-            customEgressSelector,
-            ignoreIngressSelector
+        proxyCallArgs.destination.proxyCall(
+            proxyCallArgs.revertRule,
+            proxyCallArgs.customEgressSelector,
+            proxyCallArgs.ignoreIngressSelector
         );
     }
+
+    /// @dev Calls back into this contract with the calldata that should be sent in the call
+    ///      to `proxyCall()` after setting the `proxyCallArgs` appropriately.
+    /// @param args The struct that should be set to `proxyCallArgs`.
+    /// @param data The bytes that should be used to call back into this contract.
+    function publicProxyCall(ProxyCallArguments memory args, bytes memory data)
+        public
+        returns (bool success, bytes memory returnData)
+    {
+        proxyCallArgs = args;
+        (success, returnData) = address(this).call(data);
+    }
 }

contracts/staking/contracts/test/TestLibProxyReceiver.sol

@@ -0,0 +1,45 @@
+/*
+
+  Copyright 2019 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+
+
+// solhint-disable payable-fallback
+contract TestLibProxyReceiver {
+
+    function ()
+        external
+    {
+        // Done in assembly to allow the return.
+        assembly {
+            let calldataSize := calldatasize()
+
+            // Copy all calldata into memory.
+            calldatacopy(0, 0, calldataSize)
+
+            // If the calldatasize is equal to 4, revert.
+            // This allows us to test `proxyCall` with reverts.
+            if eq(calldataSize, 4) {
+                revert(0, 4)
+            }
+
+            // Return. This allows us to test `proxyCall` with returns.
+            return(0, calldataSize)
+        }
+    }
+}