GSN compatibility (#1880)

* switch to using Context internally

* add context import

* Add smoke test to make sure enabling GSN support works

* Update test/GSN/ERC721GSNRecipientMock.test.js

Co-Authored-By: Francisco Giordano <frangio.1@gmail.com>

* Upgrade truffle

* add missing awaits

* Revert "Upgrade truffle"

This reverts commit f9b0ba9019650fdbf8919a33e6fba834689e6b04.

.editorconfig

@@ -6,7 +6,12 @@ root = true
 [*]
 charset = utf-8
 end_of_line = lf
-indent_size = 2
 indent_style = space
 insert_final_newline = true
 trim_trailing_whitespace = true
+
+[*.sol]
+indent_size = 4
+
+[*.js]
+indent_size = 2

contracts/GSN/bouncers/GSNBouncerERC20Fee.sol

@@ -20,7 +20,7 @@ contract GSNBouncerERC20Fee is Initializable, GSNBouncerBase {
     // storage layout. This value is calculated as: keccak256('gsn.bouncer.signature.token'), minus 1.
     bytes32 constant private TOKEN_STORAGE_SLOT = 0xd918b70a5a5c95a8c0cac8acbdd59e1b4acd0645f53c0461d64b41f8825c8828;
 
-    function initialize(string memory name, string memory symbol, uint8 decimals) initializer public {
+    function initialize(string memory name, string memory symbol, uint8 decimals) public initializer {
         // TODO: Should we inject this token, instead of creating it, in order to make it upgradeable?
         // However, that would mean removing it from unstable and making in an official contract
         _setToken(new __unstable__ERC20PrimaryAdmin(name, symbol, decimals));

contracts/access/roles/CapperRole.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
-import "../Roles.sol";
 
+import "../../GSN/Context.sol";
+import "../Roles.sol";
 
-contract CapperRole is Initializable {
+contract CapperRole is Initializable, Context {
     using Roles for Roles.Role;
 
     event CapperAdded(address indexed account);
@@ -19,7 +20,7 @@ contract CapperRole is Initializable {
     }
 
     modifier onlyCapper() {
-        require(isCapper(msg.sender));
+        require(isCapper(_msgSender()), "CapperRole: caller does not have the Capper role");
         _;
     }
 
@@ -32,7 +33,7 @@ contract CapperRole is Initializable {
     }
 
     function renounceCapper() public {
-        _removeCapper(msg.sender);
+        _removeCapper(_msgSender());
     }
 
     function _addCapper(address account) internal {

contracts/access/roles/MinterRole.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
-import "../Roles.sol";
 
+import "../../GSN/Context.sol";
+import "../Roles.sol";
 
-contract MinterRole is Initializable {
+contract MinterRole is Initializable, Context {
     using Roles for Roles.Role;
 
     event MinterAdded(address indexed account);
@@ -19,7 +20,7 @@ contract MinterRole is Initializable {
     }
 
     modifier onlyMinter() {
-        require(isMinter(msg.sender));
+        require(isMinter(_msgSender()), "MinterRole: caller does not have the Minter role");
         _;
     }
 
@@ -32,7 +33,7 @@ contract MinterRole is Initializable {
     }
 
     function renounceMinter() public {
-        _removeMinter(msg.sender);
+        _removeMinter(_msgSender());
     }
 
     function _addMinter(address account) internal {

contracts/access/roles/PauserRole.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
-import "../Roles.sol";
 
+import "../../GSN/Context.sol";
+import "../Roles.sol";
 
-contract PauserRole is Initializable {
+contract PauserRole is Initializable, Context {
     using Roles for Roles.Role;
 
     event PauserAdded(address indexed account);
@@ -19,7 +20,7 @@ contract PauserRole is Initializable {
     }
 
     modifier onlyPauser() {
-        require(isPauser(msg.sender));
+        require(isPauser(_msgSender()), "PauserRole: caller does not have the Pauser role");
         _;
     }
 
@@ -32,7 +33,7 @@ contract PauserRole is Initializable {
     }
 
     function renouncePauser() public {
-        _removePauser(msg.sender);
+        _removePauser(_msgSender());
     }
 
     function _addPauser(address account) internal {

contracts/access/roles/SignerRole.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
-import "../Roles.sol";
 
+import "../../GSN/Context.sol";
+import "../Roles.sol";
 
-contract SignerRole is Initializable {
+contract SignerRole is Initializable, Context {
     using Roles for Roles.Role;
 
     event SignerAdded(address indexed account);
@@ -19,7 +20,7 @@ contract SignerRole is Initializable {
     }
 
     modifier onlySigner() {
-        require(isSigner(msg.sender));
+        require(isSigner(_msgSender()), "SignerRole: caller does not have the Signer role");
         _;
     }
 
@@ -32,7 +33,7 @@ contract SignerRole is Initializable {
     }
 
     function renounceSigner() public {
-        _removeSigner(msg.sender);
+        _removeSigner(_msgSender());
     }
 
     function _addSigner(address account) internal {

contracts/access/roles/WhitelistAdminRole.sol

@@ -2,13 +2,14 @@ pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
 
+import "../../GSN/Context.sol";
 import "../Roles.sol";
 
 /**
  * @title WhitelistAdminRole
  * @dev WhitelistAdmins are responsible for assigning and removing Whitelisted accounts.
  */
-contract WhitelistAdminRole is Initializable {
+contract WhitelistAdminRole is Initializable, Context {
     using Roles for Roles.Role;
 
     event WhitelistAdminAdded(address indexed account);
@@ -23,7 +24,7 @@ contract WhitelistAdminRole is Initializable {
     }
 
     modifier onlyWhitelistAdmin() {
-        require(isWhitelistAdmin(msg.sender));
+        require(isWhitelistAdmin(_msgSender()), "WhitelistAdminRole: caller does not have the WhitelistAdmin role");
         _;
     }
 
@@ -36,7 +37,7 @@ contract WhitelistAdminRole is Initializable {
     }
 
     function renounceWhitelistAdmin() public {
-        _removeWhitelistAdmin(msg.sender);
+        _removeWhitelistAdmin(_msgSender());
     }
 
     function _addWhitelistAdmin(address account) internal {

contracts/access/roles/WhitelistedRole.sol

@@ -2,6 +2,7 @@ pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
 
+import "../../GSN/Context.sol";
 import "../Roles.sol";
 import "./WhitelistAdminRole.sol";
 
@@ -11,7 +12,7 @@ import "./WhitelistAdminRole.sol";
  * crowdsale). This role is special in that the only accounts that can add it are WhitelistAdmins (who can also remove
  * it), and not Whitelisteds themselves.
  */
-contract WhitelistedRole is Initializable, WhitelistAdminRole {
+contract WhitelistedRole is Initializable, Context, WhitelistAdminRole {
     using Roles for Roles.Role;
 
     event WhitelistedAdded(address indexed account);
@@ -20,7 +21,7 @@ contract WhitelistedRole is Initializable, WhitelistAdminRole {
     Roles.Role private _whitelisteds;
 
     modifier onlyWhitelisted() {
-        require(isWhitelisted(msg.sender));
+        require(isWhitelisted(_msgSender()), "WhitelistedRole: caller does not have the Whitelisted role");
         _;
     }
 
@@ -41,7 +42,7 @@ contract WhitelistedRole is Initializable, WhitelistAdminRole {
     }
 
     function renounceWhitelisted() public {
-        _removeWhitelisted(msg.sender);
+        _removeWhitelisted(_msgSender());
     }
 
     function _addWhitelisted(address account) internal {

contracts/crowdsale/Crowdsale.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../GSN/Context.sol";
 import "../token/ERC20/IERC20.sol";
 import "../math/SafeMath.sol";
 import "../token/ERC20/SafeERC20.sol";
@@ -18,7 +20,7 @@ import "../utils/ReentrancyGuard.sol";
  * the methods to add functionality. Consider using 'super' where appropriate to concatenate
  * behavior.
  */
-contract Crowdsale is Initializable, ReentrancyGuard {
+contract Crowdsale is Initializable, Context, ReentrancyGuard {
     using SafeMath for uint256;
     using SafeERC20 for IERC20;
 
@@ -71,7 +73,7 @@ contract Crowdsale is Initializable, ReentrancyGuard {
      * buyTokens directly when purchasing tokens from a contract.
      */
     function () external payable {
-        buyTokens(msg.sender);
+        buyTokens(_msgSender());
     }
 
     /**
@@ -119,7 +121,7 @@ contract Crowdsale is Initializable, ReentrancyGuard {
         _weiRaised = _weiRaised.add(weiAmount);
 
         _processPurchase(beneficiary, tokens);
-        emit TokensPurchased(msg.sender, beneficiary, weiAmount, tokens);
+        emit TokensPurchased(_msgSender(), beneficiary, weiAmount, tokens);
 
         _updatePurchasingState(beneficiary, weiAmount);
 

contracts/crowdsale/distribution/RefundableCrowdsale.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../../GSN/Context.sol";
 import "../../math/SafeMath.sol";
 import "./FinalizableCrowdsale.sol";
 import "../../payment/escrow/RefundEscrow.sol";
@@ -15,7 +17,7 @@ import "../../payment/escrow/RefundEscrow.sol";
  * the goal is unlikely to be met, they sell their tokens (possibly at a discount). The attacker will be refunded when
  * the crowdsale is finalized, and the users that purchased from them will be left with worthless tokens.
  */
-contract RefundableCrowdsale is Initializable, FinalizableCrowdsale {
+contract RefundableCrowdsale is Initializable, Context, FinalizableCrowdsale {
     using SafeMath for uint256;
 
     // minimum amount of funds to be raised in weis
@@ -85,7 +87,7 @@ contract RefundableCrowdsale is Initializable, FinalizableCrowdsale {
      * @dev Overrides Crowdsale fund forwarding, sending funds to escrow.
      */
     function _forwardFunds() internal {
-        _escrow.deposit.value(msg.value)(msg.sender);
+        _escrow.deposit.value(msg.value)(_msgSender());
     }
 
     uint256[50] private ______gap;

contracts/drafts/SignatureBouncer.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../GSN/Context.sol";
 import "../access/roles/SignerRole.sol";
 import "../cryptography/ECDSA.sol";
 
@@ -35,7 +37,7 @@ import "../cryptography/ECDSA.sol";
  * the data in the signature much more complex.
  * See https://ethereum.stackexchange.com/a/50616 for more details.
  */
-contract SignatureBouncer is Initializable, SignerRole {
+contract SignatureBouncer is Initializable, Context, SignerRole {
     using ECDSA for bytes32;
 
     // Function selectors are 4 bytes long, as documented in
@@ -52,7 +54,7 @@ contract SignatureBouncer is Initializable, SignerRole {
      * @dev requires that a valid signature of a signer was provided
      */
     modifier onlyValidSignature(bytes memory signature) {
-        require(_isValidSignature(msg.sender, signature));
+        require(_isValidSignature(_msgSender(), signature), "SignatureBouncer: invalid signature for caller");
         _;
     }
 
@@ -60,7 +62,8 @@ contract SignatureBouncer is Initializable, SignerRole {
      * @dev requires that a valid signature with a specified method of a signer was provided
      */
     modifier onlyValidSignatureAndMethod(bytes memory signature) {
-        require(_isValidSignatureAndMethod(msg.sender, signature));
+        // solhint-disable-next-line max-line-length
+        require(_isValidSignatureAndMethod(_msgSender(), signature), "SignatureBouncer: invalid signature for caller and method");
         _;
     }
 
@@ -68,7 +71,8 @@ contract SignatureBouncer is Initializable, SignerRole {
      * @dev requires that a valid signature with a specified method and params of a signer was provided
      */
     modifier onlyValidSignatureAndData(bytes memory signature) {
-        require(_isValidSignatureAndData(msg.sender, signature));
+        // solhint-disable-next-line max-line-length
+        require(_isValidSignatureAndData(_msgSender(), signature), "SignatureBouncer: invalid signature for caller and data");
         _;
     }
 
@@ -85,9 +89,10 @@ contract SignatureBouncer is Initializable, SignerRole {
      * @return bool
      */
     function _isValidSignatureAndMethod(address account, bytes memory signature) internal view returns (bool) {
+        bytes memory msgData = _msgData();
         bytes memory data = new bytes(_METHOD_ID_SIZE);
-        for (uint i = 0; i < data.length; i++) {
-            data[i] = msg.data[i];
+        for (uint256 i = 0; i < data.length; i++) {
+            data[i] = msgData[i];
         }
         return _isValidDataHash(keccak256(abi.encodePacked(address(this), account, data)), signature);
     }
@@ -98,11 +103,12 @@ contract SignatureBouncer is Initializable, SignerRole {
      * @return bool
      */
     function _isValidSignatureAndData(address account, bytes memory signature) internal view returns (bool) {
-        require(msg.data.length > _SIGNATURE_SIZE);
+        bytes memory msgData = _msgData();
+        require(msgData.length > _SIGNATURE_SIZE, "SignatureBouncer: data is too short");
 
-        bytes memory data = new bytes(msg.data.length - _SIGNATURE_SIZE);
-        for (uint i = 0; i < data.length; i++) {
-            data[i] = msg.data[i];
+        bytes memory data = new bytes(msgData.length - _SIGNATURE_SIZE);
+        for (uint256 i = 0; i < data.length; i++) {
+            data[i] = msgData[i];
         }
 
         return _isValidDataHash(keccak256(abi.encodePacked(address(this), account, data)), signature);

contracts/examples/SimpleToken.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../GSN/Context.sol";
 import "../token/ERC20/ERC20.sol";
 import "../token/ERC20/ERC20Detailed.sol";
 
@@ -10,16 +12,14 @@ import "../token/ERC20/ERC20Detailed.sol";
  * Note they can later distribute these tokens as they wish using `transfer` and other
  * `ERC20` functions.
  */
-contract SimpleToken is Initializable, ERC20, ERC20Detailed {
-    uint8 public constant DECIMALS = 18;
-    uint256 public constant INITIAL_SUPPLY = 10000 * (10 ** uint256(DECIMALS));
+contract SimpleToken is Initializable, Context,  ERC20, ERC20Detailed {
 
     /**
-     * @dev Constructor that gives msg.sender all of existing tokens.
+     * @dev Constructor that gives _msgSender() all of existing tokens.
      */
     function initialize(address sender) public initializer {
-        ERC20Detailed.initialize("SimpleToken", "SIM", DECIMALS);
-        _mint(sender, INITIAL_SUPPLY);
+        ERC20Detailed.initialize("SimpleToken", "SIM", 18);
+        _mint(sender, 10000 * (10 ** uint256(decimals())));
     }
 
     uint256[50] private ______gap;

contracts/lifecycle/Pausable.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../GSN/Context.sol";
 import "../access/roles/PauserRole.sol";
 
 /**
  * @title Pausable
  * @dev Base contract which allows children to implement an emergency stop mechanism.
  */
-contract Pausable is Initializable, PauserRole {
+contract Pausable is Initializable, Context, PauserRole {
     event Paused(address account);
     event Unpaused(address account);
 
@@ -47,7 +49,7 @@ contract Pausable is Initializable, PauserRole {
      */
     function pause() public onlyPauser whenNotPaused {
         _paused = true;
-        emit Paused(msg.sender);
+        emit Paused(_msgSender());
     }
 
     /**
@@ -55,7 +57,7 @@ contract Pausable is Initializable, PauserRole {
      */
     function unpause() public onlyPauser whenPaused {
         _paused = false;
-        emit Unpaused(msg.sender);
+        emit Unpaused(_msgSender());
     }
 
     uint256[50] private ______gap;

contracts/mocks/CapperRoleMock.sol

@@ -4,7 +4,7 @@ import "../access/roles/CapperRole.sol";
 
 contract CapperRoleMock is CapperRole {
     constructor() public {
-        CapperRole.initialize(msg.sender);
+        CapperRole.initialize(_msgSender());
     }
 
     function removeCapper(address account) public {

contracts/mocks/ConditionalEscrowMock.sol

@@ -7,7 +7,7 @@ contract ConditionalEscrowMock is ConditionalEscrow {
     mapping(address => bool) private _allowed;
 
     constructor() public {
-        ConditionalEscrow.initialize(msg.sender);
+        ConditionalEscrow.initialize(_msgSender());
     }
 
     function setAllowed(address payee, bool allowed) public {

contracts/mocks/ERC20CappedMock.sol

@@ -7,7 +7,7 @@ import "./MinterRoleMock.sol";
 contract ERC20CappedMock is ERC20Capped, MinterRoleMock {
 
     constructor(uint256 cap) public {
-        ERC20Capped.initialize(cap, msg.sender);
+        ERC20Capped.initialize(cap, _msgSender());
     }
 
 }

contracts/mocks/ERC20MintableMock.sol

@@ -5,6 +5,6 @@ import "./MinterRoleMock.sol";
 
 contract ERC20MintableMock is ERC20Mintable, MinterRoleMock {
     constructor() public {
-        ERC20Mintable.initialize(msg.sender);
+        ERC20Mintable.initialize(_msgSender());
     }
 }

contracts/mocks/ERC20PausableMock.sol

@@ -6,7 +6,7 @@ import "./PauserRoleMock.sol";
 // mock class using ERC20Pausable
 contract ERC20PausableMock is ERC20Pausable, PauserRoleMock {
     constructor (address initialAccount, uint initialBalance) public {
-        ERC20Pausable.initialize(msg.sender);
+        ERC20Pausable.initialize(_msgSender());
         _mint(initialAccount, initialBalance);
     }
 }

contracts/mocks/ERC721FullMock.sol

@@ -15,8 +15,8 @@ contract ERC721FullMock is ERC721Full, ERC721Mintable, ERC721MetadataMintable, E
         ERC721.initialize();
         ERC721Metadata.initialize(name, symbol);
         ERC721Enumerable.initialize();
-        ERC721Mintable.initialize(msg.sender);
-        ERC721MetadataMintable.initialize(msg.sender);
+        ERC721Mintable.initialize(_msgSender());
+        ERC721MetadataMintable.initialize(_msgSender());
     }
 
     function exists(uint256 tokenId) public view returns (bool) {

contracts/mocks/ERC721GSNRecipientMock.sol

+pragma solidity ^0.5.2;
+
+import "../token/ERC721/ERC721.sol";
+import "../GSN/GSNRecipient.sol";
+import "../GSN/bouncers/GSNBouncerSignature.sol";
+
+/**
+ * @title ERC721GSNRecipientMock
+ * A simple ERC721 mock that has GSN support enabled
+ */
+contract ERC721GSNRecipientMock is ERC721, GSNRecipient, GSNBouncerSignature {
+    constructor(address trustedSigner) public {
+        ERC721.initialize();
+        GSNRecipient.initialize();
+        GSNBouncerSignature.initialize(trustedSigner);
+    }
+
+    function mint(uint256 tokenId) public {
+        _mint(_msgSender(), tokenId);
+    }
+}

contracts/mocks/ERC721MintableBurnableImpl.sol

@@ -13,7 +13,7 @@ contract ERC721MintableBurnableImpl is ERC721Full, ERC721Mintable, ERC721Metadat
         ERC721.initialize();
         ERC721Metadata.initialize("Test", "TEST");
         ERC721Enumerable.initialize();
-        ERC721Mintable.initialize(msg.sender);
-        ERC721MetadataMintable.initialize(msg.sender);
+        ERC721Mintable.initialize(_msgSender());
+        ERC721MetadataMintable.initialize(_msgSender());
     }
 }

contracts/mocks/ERC721PausableMock.sol

@@ -10,7 +10,7 @@ import "./PauserRoleMock.sol";
 contract ERC721PausableMock is ERC721Pausable, PauserRoleMock {
     constructor() public {
         ERC721.initialize();
-        ERC721Pausable.initialize(msg.sender);
+        ERC721Pausable.initialize(_msgSender());
     }
 
     function mint(address to, uint256 tokenId) public {

contracts/mocks/EscrowMock.sol

@@ -4,6 +4,6 @@ import "../payment/escrow/Escrow.sol";
 
 contract EscrowMock is Escrow {
     constructor() public {
-        Escrow.initialize(msg.sender);
+        Escrow.initialize(_msgSender());
     }
 }

contracts/mocks/GSNBouncerERC20FeeMock.sol

@@ -6,8 +6,8 @@ import "../GSN/bouncers/GSNBouncerERC20Fee.sol";
 
 contract GSNBouncerERC20FeeMock is GSNRecipient, GSNBouncerERC20Fee {
     constructor(string memory name, string memory symbol, uint8 decimals) public {
-        GSNBouncerERC20Fee.initialize(name, symbol, decimals);
         GSNRecipient.initialize();
+        GSNBouncerERC20Fee.initialize(name, symbol, decimals);
     }
 
     function mint(address account, uint256 amount) public {

contracts/mocks/GSNBouncerSignatureMock.sol

@@ -6,8 +6,8 @@ import "../GSN/bouncers/GSNBouncerSignature.sol";
 
 contract GSNBouncerSignatureMock is GSNRecipient, GSNBouncerSignature {
     constructor(address trustedSigner) public {
-        GSNBouncerSignature.initialize(trustedSigner);
         GSNRecipient.initialize();
+        GSNBouncerSignature.initialize(trustedSigner);
     }
 
     event MockFunctionCalled();

contracts/mocks/IndividuallyCappedCrowdsaleImpl.sol

@@ -7,6 +7,6 @@ import "./CapperRoleMock.sol";
 contract IndividuallyCappedCrowdsaleImpl is IndividuallyCappedCrowdsale, CapperRoleMock {
     constructor (uint256 rate, address payable wallet, IERC20 token) public {
         Crowdsale.initialize(rate, wallet, token);
-        IndividuallyCappedCrowdsale.initialize(msg.sender);
+        IndividuallyCappedCrowdsale.initialize(_msgSender());
     }
 }

contracts/mocks/MinterRoleMock.sol

@@ -4,7 +4,7 @@ import "../access/roles/MinterRole.sol";
 
 contract MinterRoleMock is MinterRole {
     constructor() public {
-        MinterRole.initialize(msg.sender);
+        MinterRole.initialize(_msgSender());
     }
 
     function removeMinter(address account) public {

contracts/mocks/OwnableMock.sol

@@ -4,6 +4,6 @@ import "../ownership/Ownable.sol";
 
 contract OwnableMock is Ownable {
     constructor() public {
-        Ownable.initialize(msg.sender);
+        Ownable.initialize(_msgSender());
     }
 }

contracts/mocks/PausableCrowdsaleImpl.sol

@@ -6,6 +6,6 @@ import "../crowdsale/validation/PausableCrowdsale.sol";
 contract PausableCrowdsaleImpl is PausableCrowdsale {
     constructor (uint256 _rate, address payable _wallet, ERC20 _token) public {
         Crowdsale.initialize(_rate, _wallet, _token);
-        PausableCrowdsale.initialize(msg.sender);
+        PausableCrowdsale.initialize(_msgSender());
     }
 }

contracts/mocks/PausableMock.sol

@@ -9,7 +9,7 @@ contract PausableMock is Pausable, PauserRoleMock {
     uint256 public count;
 
     constructor () public {
-        Pausable.initialize(msg.sender);
+        Pausable.initialize(_msgSender());
 
         drasticMeasureTaken = false;
         count = 0;

contracts/mocks/PauserRoleMock.sol

@@ -4,7 +4,7 @@ import "../access/roles/PauserRole.sol";
 
 contract PauserRoleMock is PauserRole {
     constructor () public {
-        PauserRole.initialize(msg.sender);
+        PauserRole.initialize(_msgSender());
     }
 
     function removePauser(address account) public {

contracts/mocks/ReentrancyAttack.sol

 pragma solidity ^0.5.2;
 
-contract ReentrancyAttack {
+import "../GSN/Context.sol";
+contract ReentrancyAttack is Context {
     function callSender(bytes4 data) public {
         // solhint-disable-next-line avoid-low-level-calls
-        (bool success,) = msg.sender.call(abi.encodeWithSelector(data));
-        require(success);
+        (bool success,) = _msgSender().call(abi.encodeWithSelector(data));
+        require(success, "ReentrancyAttack: failed call");
     }
 }

contracts/mocks/RefundEscrowMock.sol

@@ -4,6 +4,6 @@ import "../payment/escrow/RefundEscrow.sol";
 
 contract RefundEscrowMock is RefundEscrow {
     constructor(address payable beneficiary) public {
-        RefundEscrow.initialize(beneficiary, msg.sender);
+        RefundEscrow.initialize(beneficiary, _msgSender());
     }
 }

contracts/mocks/SafeERC20Helper.sol

 pragma solidity ^0.5.2;
 
+import "../GSN/Context.sol";
 import "../token/ERC20/IERC20.sol";
 import "../token/ERC20/SafeERC20.sol";
 
-contract ERC20ReturnFalseMock {
+contract ERC20ReturnFalseMock is Context {
     uint256 private _allowance;
 
     // IERC20's functions are not pure, but these mock implementations are: to prevent Solidity from issuing warnings,
@@ -31,7 +32,7 @@ contract ERC20ReturnFalseMock {
     }
 }
 
-contract ERC20ReturnTrueMock {
+contract ERC20ReturnTrueMock is Context {
     mapping (address => uint256) private _allowances;
 
     // IERC20's functions are not pure, but these mock implementations are: to prevent Solidity from issuing warnings,
@@ -54,7 +55,7 @@ contract ERC20ReturnTrueMock {
     }
 
     function setAllowance(uint256 allowance_) public {
-        _allowances[msg.sender] = allowance_;
+        _allowances[_msgSender()] = allowance_;
     }
 
     function allowance(address owner, address) public view returns (uint256) {
@@ -62,7 +63,7 @@ contract ERC20ReturnTrueMock {
     }
 }
 
-contract ERC20NoReturnMock {
+contract ERC20NoReturnMock is Context {
     mapping (address => uint256) private _allowances;
 
     // IERC20's functions are not pure, but these mock implementations are: to prevent Solidity from issuing warnings,
@@ -82,7 +83,7 @@ contract ERC20NoReturnMock {
     }
 
     function setAllowance(uint256 allowance_) public {
-        _allowances[msg.sender] = allowance_;
+        _allowances[_msgSender()] = allowance_;
     }
 
     function allowance(address owner, address) public view returns (uint256) {
@@ -90,7 +91,7 @@ contract ERC20NoReturnMock {
     }
 }
 
-contract SafeERC20Wrapper {
+contract SafeERC20Wrapper is Context {
     using SafeERC20 for IERC20;
 
     IERC20 private _token;

contracts/mocks/SampleCrowdsaleMock.sol

@@ -5,7 +5,7 @@ import "../examples/SampleCrowdsale.sol";
 
 contract SampleCrowdsaleTokenMock is SampleCrowdsaleToken {
     constructor() public {
-        SampleCrowdsaleToken.initialize(msg.sender);
+        SampleCrowdsaleToken.initialize(_msgSender());
     }
 }
 

contracts/mocks/SecondaryMock.sol

@@ -4,7 +4,7 @@ import "../ownership/Secondary.sol";
 
 contract SecondaryMock is Secondary {
     constructor() public {
-        Secondary.initialize(msg.sender);
+        Secondary.initialize(_msgSender());
     }
 
     function onlyPrimaryMock() public view onlyPrimary {

contracts/mocks/SignatureBouncerMock.sol

@@ -5,7 +5,7 @@ import "./SignerRoleMock.sol";
 
 contract SignatureBouncerMock is SignatureBouncer, SignerRoleMock {
     constructor() public {
-        SignatureBouncer.initialize(msg.sender);
+        SignatureBouncer.initialize(_msgSender());
     }
 
     function checkValidSignature(address account, bytes memory signature)

contracts/mocks/SignerRoleMock.sol

@@ -4,7 +4,7 @@ import "../access/roles/SignerRole.sol";
 
 contract SignerRoleMock is SignerRole {
     constructor() public {
-        SignerRole.initialize(msg.sender);
+        SignerRole.initialize(_msgSender());
     }
 
     function removeSigner(address account) public {

contracts/mocks/SimpleTokenMock.sol

@@ -4,6 +4,6 @@ import "../examples/SimpleToken.sol";
 
 contract SimpleTokenMock is SimpleToken {
     constructor() public {
-        SimpleToken.initialize(msg.sender);
+        SimpleToken.initialize(_msgSender());
     }
 }

contracts/mocks/TokenVestingMock.sol

@@ -16,7 +16,7 @@ contract TokenVestingMock is TokenVesting {
             cliffDuration,
             duration,
             revocable,
-            msg.sender
+            _msgSender()
         );
     }
 }

contracts/mocks/WhitelistAdminRoleMock.sol

@@ -4,7 +4,7 @@ import "../access/roles/WhitelistAdminRole.sol";
 
 contract WhitelistAdminRoleMock is WhitelistAdminRole {
     constructor () public {
-        WhitelistAdminRole.initialize(msg.sender);
+        WhitelistAdminRole.initialize(_msgSender());
     }
 
     function removeWhitelistAdmin(address account) public {

contracts/mocks/WhitelistCrowdsaleImpl.sol

@@ -4,10 +4,9 @@ import "../token/ERC20/IERC20.sol";
 import "../crowdsale/validation/WhitelistCrowdsale.sol";
 import "../crowdsale/Crowdsale.sol";
 
-
 contract WhitelistCrowdsaleImpl is Crowdsale, WhitelistCrowdsale {
     constructor (uint256 _rate, address payable _wallet, IERC20 _token) public {
         Crowdsale.initialize(_rate, _wallet, _token);
-        WhitelistCrowdsale.initialize(msg.sender);
+        WhitelistCrowdsale.initialize(_msgSender());
     }
 }

contracts/mocks/WhitelistedRoleMock.sol

@@ -4,7 +4,7 @@ import "../access/roles/WhitelistedRole.sol";
 
 contract WhitelistedRoleMock is WhitelistedRole {
     constructor() public {
-        WhitelistedRole.initialize(msg.sender);
+        WhitelistedRole.initialize(_msgSender());
     }
 
     function onlyWhitelistedMock() public view onlyWhitelisted {

contracts/ownership/Ownable.sol

@@ -2,12 +2,14 @@ pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
 
+import "../GSN/Context.sol";
+
 /**
  * @title Ownable
  * @dev The Ownable contract has an owner address, and provides basic authorization control
  * functions, this simplifies the implementation of "user permissions".
  */
-contract Ownable is Initializable {
+contract Ownable is Initializable, Context {
     address private _owner;
 
     event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
@@ -40,7 +42,7 @@ contract Ownable is Initializable {
      * @return true if `msg.sender` is the owner of the contract.
      */
     function isOwner() public view returns (bool) {
-        return msg.sender == _owner;
+        return _msgSender() == _owner;
     }
 
     /**

contracts/ownership/Secondary.sol

@@ -2,11 +2,13 @@ pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
 
+import "../GSN/Context.sol";
+
 /**
  * @title Secondary
  * @dev A Secondary contract can only be used by its primary account (the one that created it)
  */
-contract Secondary is Initializable {
+contract Secondary is Initializable, Context {
     address private _primary;
 
     event PrimaryTransferred(
@@ -25,7 +27,7 @@ contract Secondary is Initializable {
      * @dev Reverts if called from any account other than the primary.
      */
     modifier onlyPrimary() {
-        require(msg.sender == _primary);
+        require(_msgSender() == _primary, "Secondary: caller is not the primary account");
         _;
     }
 

contracts/payment/PaymentSplitter.sol

@@ -2,6 +2,7 @@ pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
 
+import "../GSN/Context.sol";
 import "../math/SafeMath.sol";
 
 /**
@@ -9,7 +10,7 @@ import "../math/SafeMath.sol";
  * @dev This contract can be used when payments need to be received by a group
  * of people and split proportionately to some number of shares they own.
  */
-contract PaymentSplitter is Initializable {
+contract PaymentSplitter is Initializable, Context {
     using SafeMath for uint256;
 
     event PayeeAdded(address account, uint256 shares);
@@ -39,7 +40,7 @@ contract PaymentSplitter is Initializable {
      * @dev payable fallback
      */
     function () external payable {
-        emit PaymentReceived(msg.sender, msg.value);
+        emit PaymentReceived(_msgSender(), msg.value);
     }
 
     /**

contracts/token/ERC20/ERC20.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../../GSN/Context.sol";
 import "./IERC20.sol";
 import "../../math/SafeMath.sol";
 
@@ -16,12 +18,12 @@ import "../../math/SafeMath.sol";
  * all accounts just by listening to said events. Note that this isn't required by the specification, and other
  * compliant implementations may not do it.
  */
-contract ERC20 is Initializable, IERC20 {
+contract ERC20 is Initializable, Context, IERC20 {
     using SafeMath for uint256;
 
     mapping (address => uint256) private _balances;
 
-    mapping (address => mapping (address => uint256)) private _allowed;
+    mapping (address => mapping (address => uint256)) private _allowances;
 
     uint256 private _totalSupply;
 
@@ -48,7 +50,7 @@ contract ERC20 is Initializable, IERC20 {
      * @return A uint256 specifying the amount of tokens still available for the spender.
      */
     function allowance(address owner, address spender) public view returns (uint256) {
-        return _allowed[owner][spender];
+        return _allowances[owner][spender];
     }
 
     /**
@@ -57,7 +59,7 @@ contract ERC20 is Initializable, IERC20 {
      * @param value The amount to be transferred.
      */
     function transfer(address to, uint256 value) public returns (bool) {
-        _transfer(msg.sender, to, value);
+        _transfer(_msgSender(), to, value);
         return true;
     }
 
@@ -71,7 +73,7 @@ contract ERC20 is Initializable, IERC20 {
      * @param value The amount of tokens to be spent.
      */
     function approve(address spender, uint256 value) public returns (bool) {
-        _approve(msg.sender, spender, value);
+        _approve(_msgSender(), spender, value);
         return true;
     }
 
@@ -85,13 +87,13 @@ contract ERC20 is Initializable, IERC20 {
      */
     function transferFrom(address from, address to, uint256 value) public returns (bool) {
         _transfer(from, to, value);
-        _approve(from, msg.sender, _allowed[from][msg.sender].sub(value));
+        _approve(from, _msgSender(), _allowances[from][_msgSender()].sub(value));
         return true;
     }
 
     /**
      * @dev Increase the amount of tokens that an owner allowed to a spender.
-     * approve should be called when _allowed[msg.sender][spender] == 0. To increment
+     * approve should be called when _allowances[msg.sender][spender] == 0. To increment
      * allowed value is better to use this function to avoid 2 calls (and wait until
      * the first transaction is mined)
      * From MonolithDAO Token.sol
@@ -100,13 +102,13 @@ contract ERC20 is Initializable, IERC20 {
      * @param addedValue The amount of tokens to increase the allowance by.
      */
     function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
-        _approve(msg.sender, spender, _allowed[msg.sender][spender].add(addedValue));
+        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
         return true;
     }
 
     /**
      * @dev Decrease the amount of tokens that an owner allowed to a spender.
-     * approve should be called when _allowed[msg.sender][spender] == 0. To decrement
+     * approve should be called when _allowances[msg.sender][spender] == 0. To decrement
      * allowed value is better to use this function to avoid 2 calls (and wait until
      * the first transaction is mined)
      * From MonolithDAO Token.sol
@@ -115,7 +117,7 @@ contract ERC20 is Initializable, IERC20 {
      * @param subtractedValue The amount of tokens to decrease the allowance by.
      */
     function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
-        _approve(msg.sender, spender, _allowed[msg.sender][spender].sub(subtractedValue));
+        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue));
         return true;
     }
 
@@ -172,7 +174,7 @@ contract ERC20 is Initializable, IERC20 {
         require(spender != address(0));
         require(owner != address(0));
 
-        _allowed[owner][spender] = value;
+        _allowances[owner][spender] = value;
         emit Approval(owner, spender, value);
     }
 
@@ -182,11 +184,11 @@ contract ERC20 is Initializable, IERC20 {
      * internal burn function.
      * Emits an Approval event (reflecting the reduced allowance).
      * @param account The account whose tokens will be burnt.
-     * @param value The amount that will be burnt.
+     * @param amount The amount that will be burnt.
      */
-    function _burnFrom(address account, uint256 value) internal {
-        _burn(account, value);
-        _approve(account, msg.sender, _allowed[account][msg.sender].sub(value));
+    function _burnFrom(address account, uint256 amount) internal {
+        _burn(account, amount);
+        _approve(account, _msgSender(), _allowances[account][_msgSender()].sub(amount));
     }
 
     uint256[50] private ______gap;

contracts/token/ERC20/ERC20Burnable.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../../GSN/Context.sol";
 import "./ERC20.sol";
 
 /**
  * @title Burnable Token
  * @dev Token that can be irreversibly burned (destroyed).
  */
-contract ERC20Burnable is Initializable, ERC20 {
+contract ERC20Burnable is Initializable, Context, ERC20 {
     /**
      * @dev Burns a specific amount of tokens.
-     * @param value The amount of token to be burned.
+     * @param amount The amount of token to be burned.
      */
-    function burn(uint256 value) public {
-        _burn(msg.sender, value);
+    function burn(uint256 amount) public {
+        _burn(_msgSender(), amount);
     }
 
     /**

contracts/token/ERC721/ERC721.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../../GSN/Context.sol";
 import "./IERC721.sol";
 import "./IERC721Receiver.sol";
 import "../../math/SafeMath.sol";
@@ -12,7 +14,7 @@ import "../../introspection/ERC165.sol";
  * @title ERC721 Non-Fungible Token Standard basic implementation
  * @dev see https://eips.ethereum.org/EIPS/eip-721
  */
-contract ERC721 is Initializable, ERC165, IERC721 {
+contract ERC721 is Initializable, Context, ERC165, IERC721 {
     using SafeMath for uint256;
     using Address for address;
     using Counters for Counters.Counter;
@@ -89,8 +91,11 @@ contract ERC721 is Initializable, ERC165, IERC721 {
      */
     function approve(address to, uint256 tokenId) public {
         address owner = ownerOf(tokenId);
-        require(to != owner);
-        require(msg.sender == owner || isApprovedForAll(owner, msg.sender));
+        require(to != owner, "ERC721: approval to current owner");
+
+        require(_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
+            "ERC721: approve caller is not owner nor approved for all"
+        );
 
         _tokenApprovals[tokenId] = to;
         emit Approval(owner, to, tokenId);
@@ -114,9 +119,10 @@ contract ERC721 is Initializable, ERC165, IERC721 {
      * @param approved representing the status of the approval to be set
      */
     function setApprovalForAll(address to, bool approved) public {
-        require(to != msg.sender);
-        _operatorApprovals[msg.sender][to] = approved;
-        emit ApprovalForAll(msg.sender, to, approved);
+        require(to != _msgSender(), "ERC721: approve to caller");
+
+        _operatorApprovals[_msgSender()][to] = approved;
+        emit ApprovalForAll(_msgSender(), to, approved);
     }
 
     /**
@@ -138,7 +144,8 @@ contract ERC721 is Initializable, ERC165, IERC721 {
      * @param tokenId uint256 ID of the token to be transferred
      */
     function transferFrom(address from, address to, uint256 tokenId) public {
-        require(_isApprovedOrOwner(msg.sender, tokenId));
+        //solhint-disable-next-line max-line-length
+        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
 
         _transferFrom(from, to, tokenId);
     }
@@ -164,7 +171,7 @@ contract ERC721 is Initializable, ERC165, IERC721 {
      * which is called upon a safe transfer, and return the magic value
      * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
      * the transfer is reverted.
-     * Requires the msg.sender to be the owner, approved, or operator
+     * Requires the _msgSender() to be the owner, approved, or operator
      * @param from current owner of the token
      * @param to address to receive the ownership of the given token ID
      * @param tokenId uint256 ID of the token to be transferred
@@ -277,7 +284,7 @@ contract ERC721 is Initializable, ERC165, IERC721 {
             return true;
         }
 
-        bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);
+        bytes4 retval = IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data);
         return (retval == _ERC721_RECEIVED);
     }
 

contracts/token/ERC721/ERC721Burnable.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../../GSN/Context.sol";
 import "./ERC721.sol";
 
 /**
  * @title ERC721 Burnable Token
  * @dev ERC721 Token that can be irreversibly burned (destroyed).
  */
-contract ERC721Burnable is Initializable, ERC721 {
+contract ERC721Burnable is Initializable, Context, ERC721 {
     /**
      * @dev Burns a specific ERC721 token.
      * @param tokenId uint256 id of the ERC721 token to be burned.
      */
     function burn(uint256 tokenId) public {
-        require(_isApprovedOrOwner(msg.sender, tokenId));
+        //solhint-disable-next-line max-line-length
+        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721Burnable: caller is not owner nor approved");
         _burn(tokenId);
     }
 

contracts/token/ERC721/ERC721Enumerable.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../../GSN/Context.sol";
 import "./IERC721Enumerable.sol";
 import "./ERC721.sol";
 import "../../introspection/ERC165.sol";
@@ -9,7 +11,7 @@ import "../../introspection/ERC165.sol";
  * @title ERC-721 Non-Fungible Token with optional enumeration extension logic
  * @dev See https://eips.ethereum.org/EIPS/eip-721
  */
-contract ERC721Enumerable is Initializable, ERC165, ERC721, IERC721Enumerable {
+contract ERC721Enumerable is Initializable, Context, ERC165, ERC721, IERC721Enumerable {
     // Mapping from owner to list of owned token IDs
     mapping(address => uint256[]) private _ownedTokens;
 

contracts/token/ERC721/ERC721Metadata.sol

 pragma solidity ^0.5.2;
 
 import "@openzeppelin/upgrades/contracts/Initializable.sol";
+
+import "../../GSN/Context.sol";
 import "./ERC721.sol";
 import "./IERC721Metadata.sol";
 import "../../introspection/ERC165.sol";
 
-contract ERC721Metadata is Initializable, ERC165, ERC721, IERC721Metadata {
+contract ERC721Metadata is Initializable, Context, ERC165, ERC721, IERC721Metadata {
     // Token name
     string private _name;
 

package-lock.json

@@ -482,13 +482,15 @@
           "integrity": "sha512-7j2y+40w61zy6YC2iRNpUe/NwhNyoXrYpHMrSunaMG64nRnaf96zO/KMQR4OyN/UnE5KLyEBnKHd4aG3rskjpQ==",
           "dev": true
         },
-        "debug": {
-          "version": "3.1.0",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-3.1.0.tgz",
-          "integrity": "sha512-OX8XqP7/1a9cqkxYw2yXss15f26NKWBpDXQd0/uK/KPqdQhxbPa994hnzjcE2VqQpDslf55723cKPUOGSmMY3g==",
+        "eth-lib": {
+          "version": "0.2.7",
+          "resolved": "https://registry.npmjs.org/eth-lib/-/eth-lib-0.2.7.tgz",
+          "integrity": "sha1-L5Pxex4jrsN1nNSj/iDBKGo/wco=",
           "dev": true,
           "requires": {
-            "ms": "2.0.0"
+            "bn.js": "^4.11.6",
+            "elliptic": "^6.4.0",
+            "xhr-request-promise": "^0.1.2"
           }
         },
         "ethers": {
@@ -520,12 +522,6 @@
                 "hash.js": "^1.0.0",
                 "inherits": "^2.0.1"
               }
-            },
-            "setimmediate": {
-              "version": "1.0.4",
-              "resolved": "https://registry.npmjs.org/setimmediate/-/setimmediate-1.0.4.tgz",
-              "integrity": "sha1-IOgd5iLUoCWIzgyNqJc8vPHTE48=",
-              "dev": true
             }
           }
         },
@@ -535,15 +531,6 @@
           "integrity": "sha512-tvtQIeLVHjDkJYnzf2dgVMxfuSGJeM/7UCG17TT4EumTfNtF+0nebF/4zWOIkCreAbtNqhGEboB6BWrwqNaw4Q==",
           "dev": true
         },
-        "follow-redirects": {
-          "version": "1.5.10",
-          "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.5.10.tgz",
-          "integrity": "sha512-0V5l4Cizzvqt5D44aTXbFZz+FtyXV1vrDN6qrelxtfYQKW0KO0W2T/hkE8xvGa/540LkZlkaUjO4ailYTFtHVQ==",
-          "dev": true,
-          "requires": {
-            "debug": "=3.1.0"
-          }
-        },
         "fs-extra": {
           "version": "8.1.0",
           "resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-8.1.0.tgz",
@@ -575,6 +562,12 @@
           "integrity": "sha512-b9usnbDGnD928gJB3LrCmxoibr3VE4U2SMo5PBuBnokWyDADTqDPXg4YpwKF1trpH+UbGp7QLicO3+aWEy0+mw==",
           "dev": true
         },
+        "js-sha3": {
+          "version": "0.5.7",
+          "resolved": "https://registry.npmjs.org/js-sha3/-/js-sha3-0.5.7.tgz",
+          "integrity": "sha1-DU/9gALVMzqrr0oj7tL2N0yfKOc=",
+          "dev": true
+        },
         "jsonfile": {
           "version": "4.0.0",
           "resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
@@ -644,12 +637,6 @@
           "integrity": "sha512-jdFC1VdUGT/2Scgbimf7FSx9iJLXoqfglSF+gJeuNWVpiE37OIbc1jywR/GJyFdz3mnkz2/id0L0J/cr0izR5A==",
           "dev": true
         },
-        "setimmediate": {
-          "version": "1.0.5",
-          "resolved": "https://registry.npmjs.org/setimmediate/-/setimmediate-1.0.5.tgz",
-          "integrity": "sha1-KQy7Iy4waULX1+qbg3Mqt4VvgoU=",
-          "dev": true
-        },
         "swarm-js": {
           "version": "0.1.39",
           "resolved": "https://registry.npmjs.org/swarm-js/-/swarm-js-0.1.39.tgz",
@@ -670,6 +657,21 @@
             "xhr-request-promise": "^0.1.2"
           },
           "dependencies": {
+            "eth-lib": {
+              "version": "0.1.27",
+              "resolved": "https://registry.npmjs.org/eth-lib/-/eth-lib-0.1.27.tgz",
+              "integrity": "sha512-B8czsfkJYzn2UIEMwjc7Mbj+Cy72V+/OXH/tb44LV8jhrjizQJJ325xMOMyk3+ETa6r6oi0jsUY14+om8mQMWA==",
+              "dev": true,
+              "requires": {
+                "bn.js": "^4.11.6",
+                "elliptic": "^6.4.0",
+                "keccakjs": "^0.2.1",
+                "nano-json-stream-parser": "^0.1.2",
+                "servify": "^0.1.12",
+                "ws": "^3.0.0",
+                "xhr-request-promise": "^0.1.2"
+              }
+            },
             "fs-extra": {
               "version": "4.0.3",
               "resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-4.0.3.tgz",
@@ -702,6 +704,12 @@
                 "url-parse-lax": "^1.0.0",
                 "url-to-options": "^1.0.1"
               }
+            },
+            "setimmediate": {
+              "version": "1.0.5",
+              "resolved": "https://registry.npmjs.org/setimmediate/-/setimmediate-1.0.5.tgz",
+              "integrity": "sha1-KQy7Iy4waULX1+qbg3Mqt4VvgoU=",
+              "dev": true
             }
           }
         },
@@ -888,17 +896,6 @@
             "web3-utils": "1.2.1"
           },
           "dependencies": {
-            "eth-lib": {
-              "version": "0.2.7",
-              "resolved": "https://registry.npmjs.org/eth-lib/-/eth-lib-0.2.7.tgz",
-              "integrity": "sha1-L5Pxex4jrsN1nNSj/iDBKGo/wco=",
-              "dev": true,
-              "requires": {
-                "bn.js": "^4.11.6",
-                "elliptic": "^6.4.0",
-                "xhr-request-promise": "^0.1.2"
-              }
-            },
             "uuid": {
               "version": "3.3.2",
               "resolved": "https://registry.npmjs.org/uuid/-/uuid-3.3.2.tgz",
@@ -1030,19 +1027,6 @@
             "randomhex": "0.1.5",
             "underscore": "1.9.1",
             "utf8": "3.0.0"
-          },
-          "dependencies": {
-            "eth-lib": {
-              "version": "0.2.7",
-              "resolved": "https://registry.npmjs.org/eth-lib/-/eth-lib-0.2.7.tgz",
-              "integrity": "sha1-L5Pxex4jrsN1nNSj/iDBKGo/wco=",
-              "dev": true,
-              "requires": {
-                "bn.js": "^4.11.6",
-                "elliptic": "^6.4.0",
-                "xhr-request-promise": "^0.1.2"
-              }
-            }
           }
         },
         "websocket": {
@@ -1056,17 +1040,6 @@
             "nan": "^2.14.0",
             "typedarray-to-buffer": "^3.1.5",
             "yaeti": "^0.0.6"
-          },
-          "dependencies": {
-            "debug": {
-              "version": "2.6.9",
-              "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
-              "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
-              "dev": true,
-              "requires": {
-                "ms": "2.0.0"
-              }
-            }
           }
         }
       }
@@ -3897,12 +3870,12 @@
       }
     },
     "color-convert": {
-      "version": "1.9.1",
-      "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.1.tgz",
-      "integrity": "sha512-mjGanIiwQJskCC18rPR6OmrZ6fm2Lc7PeGFYwCmy5J34wC6F1PzdGL6xeMfmgicfYcNLGuVFA3WzXtIDCQSZxQ==",
+      "version": "1.9.3",
+      "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+      "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
       "dev": true,
       "requires": {
-        "color-name": "^1.1.1"
+        "color-name": "1.1.3"
       }
     },
     "color-name": {
@@ -4076,28 +4049,6 @@
         "vary": "^1"
       }
     },
-    "coveralls": {
-      "version": "3.0.6",
-      "resolved": "https://registry.npmjs.org/coveralls/-/coveralls-3.0.6.tgz",
-      "integrity": "sha512-Pgh4v3gCI4T/9VijVrm8Ym5v0OgjvGLKj3zTUwkvsCiwqae/p6VLzpsFNjQS2i6ewV7ef+DjFJ5TSKxYt/mCrA==",
-      "dev": true,
-      "requires": {
-        "growl": "~> 1.10.0",
-        "js-yaml": "^3.13.1",
-        "lcov-parse": "^0.0.10",
-        "log-driver": "^1.2.7",
-        "minimist": "^1.2.0",
-        "request": "^2.86.0"
-      },
-      "dependencies": {
-        "minimist": {
-          "version": "1.2.0",
-          "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.0.tgz",
-          "integrity": "sha1-o1AIsg9BOD7sH7kU9M1d95omQoQ=",
-          "dev": true
-        }
-      }
-    },
     "create-ecdh": {
       "version": "4.0.3",
       "resolved": "https://registry.npmjs.org/create-ecdh/-/create-ecdh-4.0.3.tgz",
@@ -6328,6 +6279,26 @@
         }
       }
     },
+    "follow-redirects": {
+      "version": "1.5.10",
+      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.5.10.tgz",
+      "integrity": "sha512-0V5l4Cizzvqt5D44aTXbFZz+FtyXV1vrDN6qrelxtfYQKW0KO0W2T/hkE8xvGa/540LkZlkaUjO4ailYTFtHVQ==",
+      "dev": true,
+      "requires": {
+        "debug": "=3.1.0"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "3.1.0",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-3.1.0.tgz",
+          "integrity": "sha512-OX8XqP7/1a9cqkxYw2yXss15f26NKWBpDXQd0/uK/KPqdQhxbPa994hnzjcE2VqQpDslf55723cKPUOGSmMY3g==",
+          "dev": true,
+          "requires": {
+            "ms": "2.0.0"
+          }
+        }
+      }
+    },
     "for-each": {
       "version": "0.3.3",
       "resolved": "https://registry.npmjs.org/for-each/-/for-each-0.3.3.tgz",
@@ -9708,12 +9679,6 @@
         "invert-kv": "^1.0.0"
       }
     },
-    "lcov-parse": {
-      "version": "0.0.10",
-      "resolved": "https://registry.npmjs.org/lcov-parse/-/lcov-parse-0.0.10.tgz",
-      "integrity": "sha1-GwuP+ayceIklBYK3C3ExXZ2m2aM=",
-      "dev": true
-    },
     "lead": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/lead/-/lead-1.0.0.tgz",
@@ -10129,12 +10094,6 @@
       "integrity": "sha1-PNRXSgC2e643OpS3SHcmQFB7eqw=",
       "dev": true
     },
-    "log-driver": {
-      "version": "1.2.7",
-      "resolved": "https://registry.npmjs.org/log-driver/-/log-driver-1.2.7.tgz",
-      "integrity": "sha512-U7KCmLdqsGHBLeWqYlFA0V0Sl6P08EE1ZrmA9cxjUE0WVqT9qnyVDPz1kzpFEP0jdJuFnasWIfSd7fsaNXkpbg==",
-      "dev": true
-    },
     "lowercase-keys": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/lowercase-keys/-/lowercase-keys-1.0.1.tgz",

package.json

@@ -44,9 +44,8 @@
     "@openzeppelin/gsn-helpers": "^0.1.5",
     "@openzeppelin/gsn-provider": "^0.1.5",
     "@openzeppelin/upgrades": "2.5.0",
-    "chai": "^4.1.2",
+    "chai": "^4.2.0",
     "chai-bn": "^0.1.1",
-    "coveralls": "^3.0.1",
     "eslint": "^4.19.1",
     "eslint-config-standard": "^10.2.1",
     "eslint-plugin-import": "^2.13.0",

test/GSN/ERC721GSNRecipientMock.test.js

+const { constants, expectEvent } = require('openzeppelin-test-helpers');
+const { ZERO_ADDRESS } = constants;
+const gsn = require('@openzeppelin/gsn-helpers');
+const { fixSignature } = require('../helpers/sign');
+const { utils: { toBN } } = require('web3');
+
+const ERC721GSNRecipientMock = artifacts.require('ERC721GSNRecipientMock');
+
+contract('ERC721GSNRecipient (integration)', function ([_, signer, sender]) {
+  const tokenId = '42';
+
+  beforeEach(async function () {
+    this.token = await ERC721GSNRecipientMock.new(signer);
+  });
+
+  async function testMintToken (token, from, tokenId, options = {}) {
+    const { tx } = await token.mint(tokenId, { from, ...options });
+    await expectEvent.inTransaction(tx, ERC721GSNRecipientMock, 'Transfer', { from: ZERO_ADDRESS, to: from, tokenId });
+  }
+
+  context('when called directly', function () {
+    it('sender can mint tokens', async function () {
+      await testMintToken(this.token, sender, tokenId);
+    });
+  });
+
+  context('when relay-called', function () {
+    beforeEach(async function () {
+      await gsn.fundRecipient(web3, { recipient: this.token.address });
+    });
+
+    it('sender can mint tokens', async function () {
+      const approveFunction = async (data) =>
+        fixSignature(
+          await web3.eth.sign(
+            web3.utils.soliditySha3(
+              // eslint-disable-next-line max-len
+              data.relayerAddress, data.from, data.encodedFunctionCall, toBN(data.txFee), toBN(data.gasPrice), toBN(data.gas), toBN(data.nonce), data.relayHubAddress, this.token.address
+            ), signer
+          )
+        );
+
+      await testMintToken(this.token, sender, tokenId, { useGSN: true, approveFunction });
+    });
+  });
+});