ERC1155 feature pending tasks (#2014)

* Initial ERC1155 implementation with some tests (#1803)

* Initial ERC1155 implementation with some tests

* Remove mocked isERC1155TokenReceiver

* Revert reason edit nit

* Remove parameters associated with isERC1155TokenReceiver call

* Add tests for approvals and single transfers

* Add tests for transferring to contracts

* Add tests for batch transfers

* Make expectEvent.inTransaction tests async

* Renamed "owner" to "account" and "holder"

* Document unspecified balanceOfBatch reversion on zero behavior

* Ensure accounts can't set their own operator status

* Specify descriptive messages for underflow errors

* Bring SafeMath.add calls in line with OZ style

* Explicitly prevent _burn on the zero account

* Implement batch minting/burning

* Refactored operator approval check into isApprovedForAll calls

* Renamed ERC1155TokenReceiver to ERC1155Receiver

* Added ERC1155Holder

* Fix lint issues

* Migrate tests to @openzeppelin/test-environment

* Port ERC 1155 branch to Solidity 0.6 (and current master) (#2130)

* port ERC1155 to Solidity 0.6

* make ERC1155 constructor more similar to ERC721 one

* also migrate mock contracts to Solidity 0.6

* mark all non-view functions as virtual

Co-authored-by: Alan Lu <alanlu1023@gmail.com>
Co-authored-by: Nicolás Venturo <nicolas.venturo@gmail.com>
Co-authored-by: Robert Kaiser <kairo@kairo.at>

contracts/mocks/ERC1155Mock.sol

@@ -0,0 +1,33 @@
+pragma solidity ^0.6.0;
+
+import "../token/ERC1155/ERC1155.sol";
+
+/**
+ * @title ERC1155Mock
+ * This mock just publicizes internal functions for testing purposes
+ */
+contract ERC1155Mock is ERC1155 {
+    function mint(address to, uint256 id, uint256 value, bytes memory data) public {
+        _mint(to, id, value, data);
+    }
+
+    function mintBatch(address to, uint256[] memory ids, uint256[] memory values, bytes memory data) public {
+        _mintBatch(to, ids, values, data);
+    }
+
+    function burn(address owner, uint256 id, uint256 value) public {
+        _burn(owner, id, value);
+    }
+
+    function burnBatch(address owner, uint256[] memory ids, uint256[] memory values) public {
+        _burnBatch(owner, ids, values);
+    }
+
+    function doSafeTransferAcceptanceCheck(address operator, address from, address to, uint256 id, uint256 value, bytes memory data) public {
+        _doSafeTransferAcceptanceCheck(operator, from, to, id, value, data);
+    }
+
+    function doSafeBatchTransferAcceptanceCheck(address operator, address from, address to, uint256[] memory ids, uint256[] memory values, bytes memory data) public {
+        _doSafeBatchTransferAcceptanceCheck(operator, from, to, ids, values, data);
+    }
+}

contracts/mocks/ERC1155ReceiverMock.sol

@@ -0,0 +1,60 @@
+pragma solidity ^0.6.0;
+
+import "../token/ERC1155/IERC1155Receiver.sol";
+import "./ERC165Mock.sol";
+
+contract ERC1155ReceiverMock is IERC1155Receiver, ERC165Mock {
+    bytes4 private _recRetval;
+    bool private _recReverts;
+    bytes4 private _batRetval;
+    bool private _batReverts;
+
+    event Received(address operator, address from, uint256 id, uint256 value, bytes data, uint256 gas);
+    event BatchReceived(address operator, address from, uint256[] ids, uint256[] values, bytes data, uint256 gas);
+
+    constructor (
+        bytes4 recRetval,
+        bool recReverts,
+        bytes4 batRetval,
+        bool batReverts
+    )
+        public
+    {
+        _recRetval = recRetval;
+        _recReverts = recReverts;
+        _batRetval = batRetval;
+        _batReverts = batReverts;
+    }
+
+    function onERC1155Received(
+        address operator,
+        address from,
+        uint256 id,
+        uint256 value,
+        bytes calldata data
+    )
+        external
+        override
+        returns(bytes4)
+    {
+        require(!_recReverts, "ERC1155ReceiverMock: reverting on receive");
+        emit Received(operator, from, id, value, data, gasleft());
+        return _recRetval;
+    }
+
+    function onERC1155BatchReceived(
+        address operator,
+        address from,
+        uint256[] calldata ids,
+        uint256[] calldata values,
+        bytes calldata data
+    )
+        external
+        override
+        returns(bytes4)
+    {
+        require(!_batReverts, "ERC1155ReceiverMock: reverting on batch receive");
+        emit BatchReceived(operator, from, ids, values, data, gasleft());
+        return _batRetval;
+    }
+}