Add functionStaticCall and functionDelegateCall methods to Address library (#2333)

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

CHANGELOG.md

 # Changelog
 
+## 3.3.0 (unreleased)
+
+ * `Address`: added `functionStaticCall` and `functionDelegateCall`, similar to the existing `functionCall`. ([#2333](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2333))
+
 ## 3.2.0 (2020-09-10)
 
 ### New features

contracts/mocks/AddressImpl.sol

@@ -5,6 +5,8 @@ pragma solidity ^0.6.0;
 import "../utils/Address.sol";
 
 contract AddressImpl {
+    string public sharedAnswer;
+
     event CallReturnValue(string data);
 
     function isContract(address account) external view returns (bool) {
@@ -17,13 +19,21 @@ contract AddressImpl {
 
     function functionCall(address target, bytes calldata data) external {
         bytes memory returnData = Address.functionCall(target, data);
-
         emit CallReturnValue(abi.decode(returnData, (string)));
     }
 
     function functionCallWithValue(address target, bytes calldata data, uint256 value) external payable {
         bytes memory returnData = Address.functionCallWithValue(target, data, value);
+        emit CallReturnValue(abi.decode(returnData, (string)));
+    }
+
+    function functionStaticCall(address target, bytes calldata data) external {
+        bytes memory returnData = Address.functionStaticCall(target, data);
+        emit CallReturnValue(abi.decode(returnData, (string)));
+    }
 
+    function functionDelegateCall(address target, bytes calldata data) external {
+        bytes memory returnData = Address.functionDelegateCall(target, data);
         emit CallReturnValue(abi.decode(returnData, (string)));
     }
 

contracts/mocks/CallReceiverMock.sol

@@ -3,6 +3,7 @@
 pragma solidity ^0.6.0;
 
 contract CallReceiverMock {
+    string public sharedAnswer;
 
     event MockFunctionCalled();
 
@@ -20,6 +21,10 @@ contract CallReceiverMock {
         return "0x1234";
     }
 
+    function mockStaticFunction() public pure returns (string memory) {
+        return "0x1234";
+    }
+
     function mockFunctionRevertsNoReason() public payable {
         revert();
     }
@@ -37,4 +42,9 @@ contract CallReceiverMock {
             _array.push(i);
         }
     }
+
+    function mockFunctionWritesStorage() public returns (string memory) {
+        sharedAnswer = "42";
+        return "0x1234";
+    }
 }

contracts/utils/Address.sol

@@ -87,7 +87,7 @@ library Address {
      * _Available since v3.1._
      */
     function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
-        return _functionCallWithValue(target, data, 0, errorMessage);
+        return functionCallWithValue(target, data, 0, errorMessage);
     }
 
     /**
@@ -113,14 +113,62 @@ library Address {
      */
     function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
         require(address(this).balance >= value, "Address: insufficient balance for call");
-        return _functionCallWithValue(target, data, value, errorMessage);
+        require(isContract(target), "Address: call to non-contract");
+
+        // solhint-disable-next-line avoid-low-level-calls
+        (bool success, bytes memory returndata) = target.call{ value: value }(data);
+        return _verifyCallResult(success, returndata, errorMessage);
     }
 
-    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
-        require(isContract(target), "Address: call to non-contract");
+    /**
+     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
+     * but performing a static call.
+     *
+     * _Available since v3.3._
+     */
+    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
+        return functionStaticCall(target, data, "Address: low-level static call failed");
+    }
+
+    /**
+     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
+     * but performing a static call.
+     *
+     * _Available since v3.3._
+     */
+    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
+        require(isContract(target), "Address: static call to non-contract");
+
+        // solhint-disable-next-line avoid-low-level-calls
+        (bool success, bytes memory returndata) = target.staticcall(data);
+        return _verifyCallResult(success, returndata, errorMessage);
+    }
+
+    /**
+     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
+     * but performing a delegate call.
+     *
+     * _Available since v3.3._
+     */
+    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
+        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
+    }
+
+    /**
+     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
+     * but performing a delegate call.
+     *
+     * _Available since v3.3._
+     */
+    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
+        require(isContract(target), "Address: delegate call to non-contract");
 
         // solhint-disable-next-line avoid-low-level-calls
-        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
+        (bool success, bytes memory returndata) = target.delegatecall(data);
+        return _verifyCallResult(success, returndata, errorMessage);
+    }
+
+    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
         if (success) {
             return returndata;
         } else {

test/utils/Address.test.js

@@ -143,6 +143,7 @@ describe('Address', function () {
       // which cause a mockFunctionOutOfGas function to crash Ganache and the
       // subsequent tests before running out of gas.
       it('reverts when the called function runs out of gas', async function () {
+        this.timeout(10000);
         if (coverage) { return this.skip(); }
         const abiEncodedCall = web3.eth.abi.encodeFunctionCall({
           name: 'mockFunctionOutOfGas',
@@ -154,7 +155,7 @@ describe('Address', function () {
           this.mock.functionCall(this.contractRecipient.address, abiEncodedCall),
           'Address: low-level call failed',
         );
-      }).timeout(5000);
+      });
 
       it('reverts when the called function throws', async function () {
         const abiEncodedCall = web3.eth.abi.encodeFunctionCall({
@@ -285,4 +286,107 @@ describe('Address', function () {
       });
     });
   });
+
+  describe('functionStaticCall', function () {
+    beforeEach(async function () {
+      this.contractRecipient = await CallReceiverMock.new();
+    });
+
+    it('calls the requested function', async function () {
+      const abiEncodedCall = web3.eth.abi.encodeFunctionCall({
+        name: 'mockStaticFunction',
+        type: 'function',
+        inputs: [],
+      }, []);
+
+      const receipt = await this.mock.functionStaticCall(this.contractRecipient.address, abiEncodedCall);
+
+      expectEvent(receipt, 'CallReturnValue', { data: '0x1234' });
+    });
+
+    it('reverts on a non-static function', async function () {
+      const abiEncodedCall = web3.eth.abi.encodeFunctionCall({
+        name: 'mockFunction',
+        type: 'function',
+        inputs: [],
+      }, []);
+
+      await expectRevert(
+        this.mock.functionStaticCall(this.contractRecipient.address, abiEncodedCall),
+        'Address: low-level static call failed',
+      );
+    });
+
+    it('bubbles up revert reason', async function () {
+      const abiEncodedCall = web3.eth.abi.encodeFunctionCall({
+        name: 'mockFunctionRevertsReason',
+        type: 'function',
+        inputs: [],
+      }, []);
+
+      await expectRevert(
+        this.mock.functionStaticCall(this.contractRecipient.address, abiEncodedCall),
+        'CallReceiverMock: reverting',
+      );
+    });
+
+    it('reverts when address is not a contract', async function () {
+      const [ recipient ] = accounts;
+      const abiEncodedCall = web3.eth.abi.encodeFunctionCall({
+        name: 'mockFunction',
+        type: 'function',
+        inputs: [],
+      }, []);
+      await expectRevert(
+        this.mock.functionStaticCall(recipient, abiEncodedCall),
+        'Address: static call to non-contract',
+      );
+    });
+  });
+
+  describe('functionDelegateCall', function () {
+    beforeEach(async function () {
+      this.contractRecipient = await CallReceiverMock.new();
+    });
+
+    it('delegate calls the requested function', async function () {
+      const abiEncodedCall = web3.eth.abi.encodeFunctionCall({
+        name: 'mockFunctionWritesStorage',
+        type: 'function',
+        inputs: [],
+      }, []);
+
+      const receipt = await this.mock.functionDelegateCall(this.contractRecipient.address, abiEncodedCall);
+
+      expectEvent(receipt, 'CallReturnValue', { data: '0x1234' });
+
+      expect(await this.mock.sharedAnswer()).to.equal('42');
+    });
+
+    it('bubbles up revert reason', async function () {
+      const abiEncodedCall = web3.eth.abi.encodeFunctionCall({
+        name: 'mockFunctionRevertsReason',
+        type: 'function',
+        inputs: [],
+      }, []);
+
+      await expectRevert(
+        this.mock.functionDelegateCall(this.contractRecipient.address, abiEncodedCall),
+        'CallReceiverMock: reverting',
+      );
+    });
+
+    it('reverts when address is not a contract', async function () {
+      const [ recipient ] = accounts;
+      const abiEncodedCall = web3.eth.abi.encodeFunctionCall({
+        name: 'mockFunction',
+        type: 'function',
+        inputs: [],
+      }, []);
+      await expectRevert(
+        this.mock.functionDelegateCall(recipient, abiEncodedCall),
+        'Address: delegate call to non-contract',
+      );
+    });
+  });
 });