Merge tag 'v2.1.1' of github.com:OpenZeppelin/openzeppelin-solidity

v2.1.1

.env.example

-# configure your infura api key (not technically required)
-INFURA_API_KEY=
-
-# change the mnemonic that your hd wallet is seeded with
-MNEMONIC=

.eslintrc

 {
   "extends" : [
     "standard",
-    "plugin:promise/recommended"
+    "plugin:promise/recommended",
   ],
   "plugins": [
-    "promise"
+    "mocha-no-only",
+    "promise",
   ],
   "env": {
     "browser" : true,
     "node"    : true,
     "mocha"   : true,
-    "jest"    : true
+    "jest"    : true,
   },
   "globals" : {
     "artifacts": false,
     "contract": false,
     "assert": false,
-    "web3": false
+    "web3": false,
   },
   "rules": {
 
@@ -25,7 +26,7 @@
 
     // Code style
     "camelcase": ["error", {"properties": "always"}],
-    "comma-dangle": ["warn", "always-multiline"],
+    "comma-dangle": ["error", "always-multiline"],
     "comma-spacing": ["error", {"before": false, "after": true}],
     "dot-notation": ["error", {"allowKeywords": true, "allowPattern": ""}],
     "eol-last": ["error", "always"],
@@ -49,6 +50,8 @@
     "semi": ["error", "always"],
     "space-before-function-paren": ["error", "always"],
 
+    "mocha-no-only/mocha-no-only": ["error"],
+
     "promise/always-return": "off",
     "promise/avoid-new": "off",
   }

.github/ISSUE_TEMPLATE.md

-## 🎉 Description
-
-<!-- Briefly describe the issue you are experiencing (or the feature you want to see added to OpenZeppelin). Tell us what you were trying to do and what happened instead. **Remember, this is _not_ a place to ask for help debugging code; for that, we welcome you in the [OpenZeppelin Slack Channel](https://slack.openzeppelin.org/).** -->
-
-- [ ] 🐛 This is a bug report.
-- [ ] 📈 This is a feature request.
-
-<!-- Please check one of the above by placing an x in the box. -->
-
-## 💻 Environment
-
-Next, we need to know what your environment looks like.
-
-- Which version of OpenZeppelin are you using?
-- What network are you deploying to? Ganache? Ropsten?
-- How are you deploying your OpenZeppelin-backed contracts? truffle? Remix? Let us know!
-
-## 📝 Details
-
-Describe the problem you have been experiencing in more detail. Include as much information as you think is relevant. Keep in mind that transactions can fail for many reasons; context is key here.
-
-## 🔢 Code To Reproduce Issue [ Good To Have ]
-
-Please remember that with sample code it's easier to reproduce the bug and it's much faster to fix it.
-
-```
-insert short code snippets here
-```
-
-<!-- If your code is larger, consider linking us to a repo illustrating your issue. -->
-
-## 👍 Other Information
-
-<!-- List any other information that is relevant to your issue. Error logs, related issues, suggestions on how to fix, Stack Overflow links, forum links, etc. -->

.github/ISSUE_TEMPLATE/bug_report.md

+---
+name: Bug report
+about: Report a bug in OpenZeppelin
+
+---
+
+<!-- Briefly describe the issue you're experiencing. Tell us what you were trying to do and what happened instead. -->
+
+<!-- Remember, this is not a place to ask for help debugging code. For that, we welcome you in the OpenZeppelin Slack channel: https://slack.openzeppelin.org/. -->
+
+**💻 Environment**
+
+<!-- Tell us what version of OpenZeppelin you're using, and how you're using it: Truffle, Remix, etc. -->
+
+**📝 Details**
+
+<!-- Describe the problem you have been experiencing in more detail. Include as much information as you think is relevant. Keep in mind that transactions can fail for many reasons; context is key here. -->
+
+**🔢 Code to reproduce bug**
+
+<!-- We will be able to better help if you provide a minimal example that triggers the bug. -->

.github/ISSUE_TEMPLATE/feature_request.md

+---
+name: Feature request
+about: Suggest an idea for OpenZeppelin
+
+---
+
+**🧐 Motivation**
+<!-- Is your feature request related to a specific problem? Is it just a crazy idea? Tell us about it! -->
+
+**📝 Details**
+<!-- Please describe your feature request in detail. -->
+
+<!-- Make sure that you have reviewed the OpenZeppelin Contributor Guidelines. -->
+<!-- https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/CONTRIBUTING.md -->

.github/PULL_REQUEST_TEMPLATE.md

 <!-- 0. 🎉 Thank you for submitting a PR! -->
 
-<!-- 1. **Does this close any open issues?** If so, list them here. If not, remove the `Fixes #` line. -->
+<!-- 1. Does this close any open issues? Please list them below. -->
 
-Fixes #
+<!-- Keep in mind that new features have a better chance of being merged fast if
+they were first discussed and designed with the maintainers. If there is no
+corresponding issue, please consider opening one for discussion first! -->
 
-# 🚀 Description
+Fixes #
 
-<!-- 2. Describe the changes introduced in this pull request -->
+<!-- 2. Describe the changes introduced in this pull request. -->
 <!--    Include any context necessary for understanding the PR's purpose. -->
 
-<!-- 3. Before submitting, please review the following checklist: -->
-
-- [ ] 📘 I've reviewed the [OpenZeppelin Contributor Guidelines](../blob/master/CONTRIBUTING.md)
-- [ ] ✅ I've added tests where applicable to test my new functionality.
-- [ ] 📖 I've made sure that my contracts are well-documented.
-- [ ] 🎨 I've run the JS/Solidity linters and fixed any issues (`npm run lint:fix`).
+<!-- 3. Before submitting, please make sure that you have:
+  - reviewed the OpenZeppelin Contributor Guidelines
+    (https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/CONTRIBUTING.md),
+  - added tests where applicable to test new functionality,
+  - made sure that your contracts are well-documented,
+  - run the JS/Solidity linters and fixed any issues (`npm run lint:fix`), and
+  - updated the changelog, if applicable.
+-->

.gitignore

@@ -38,4 +38,9 @@ build/
 # truffle
 .node-xmlhttprequest-*
 
+<<<<<<< HEAD
 .zos.session
+=======
+# Temporary directory for 0.5.x compilation
+solc-0.5
+>>>>>>> 8fc0a3af313d9372fc9b8d3e5dc57b804df0588e

.solhint.json

+{
+  "extends": "default",
+  "rules": {
+    "indent": ["error", 4],
+
+    "bracket-align": false,
+    "compiler-fixed": false,
+    "no-simple-event-func-name": false,
+    "two-lines-top-level-separator": false
+  }
+}

.soliumignore

-node_modules

.soliumrc.json

-{
-  "extends": "solium:all",
-  "plugins": ["security"],
-  "rules": {
-    "error-reason": "off",
-    "indentation": ["error", 2],
-    "lbrace": "off",
-    "linebreak-style": ["error", "unix"],
-    "max-len": ["error", 120],
-    "no-constant": ["error"],
-    "no-empty-blocks": "off",
-    "quotes": ["error", "double"],
-    "uppercase": "off",
-    "visibility-first": "error",
-
-    "security/enforce-explicit-visibility": ["error"],
-    "security/no-block-members": ["warning"],
-    "security/no-inline-assembly": ["warning"]
-  }
-}

.travis.yml

@@ -15,38 +15,26 @@ jobs:
   # --elopio - 20180531
   fast_finish: true
   allow_failures:
-    - env: SOLIDITY_COVERAGE=true
     - env: SOLC_NIGHTLY=true
   include:
-    - stage: install
-      script: true
-      install:
-        - npm install
-        - npx npm-install-peers
-    # Run the unit test suite three times in parallel.
-    # The first one gets results faster and is the only one required to pass.
-    # The second one generates the coverage report.
-    # The third one is to keep us informed about possible issues with the
-    # upcoming solidity release.
     - stage: tests
-      name: "unit tests"
-      install: npx npm-install-peers
+      name: "Linter"
+      script: npm run lint
+
+    - stage: tests
+      name: "Unit tests"
       script: npm run test
+
     - stage: tests
-      name: "unit tests with coverage"
-      install: npx npm-install-peers
+      name: "Unit tests with coverage report"
       script: npm run test
       env: SOLIDITY_COVERAGE=true
+
     - stage: tests
-      name: "unit tests with solc nightly"
-      install: npx npm-install-peers
+      name: "Unit tests using solc nightly"
       script: npm run test
       env: SOLC_NIGHTLY=true
-    # solidity and javascript style tests.
-    - stage: tests
-      name: "static tests"
-      install: npx npm-install-peers
-      script: npm run lint
+
     - stage: update docs
       if: tag =~ ^v[0-9]+\.[0-9]+\.[0-9]+$
       addons:

CHANGELOG.md

+# Changelog
+
+## 2.1.1 (2019-04-01)
+ * Version bump to avoid conflict in the npm registry.
+
+## 2.1.0 (2019-04-01)
+
+### New features:
+ * Now targeting the 0.5.x line of Solidity compilers. For 0.4.24 support, use version 2.0 of OpenZeppelin.
+ * `WhitelistCrowdsale`: a crowdsale where only whitelisted accounts (`WhitelistedRole`) can purchase tokens. Adding or removing accounts from the whitelist is done by whitelist admins (`WhitelistAdminRole`). Similar to the pre-2.0 `WhitelistedCrowdsale`. ([#1525](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1525), [#1589](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1589))
+ * `RefundablePostDeliveryCrowdsale`: replacement for `RefundableCrowdsale` (deprecated, see below) where tokens are only granted once the crowdsale ends (if it meets its goal). ([#1543](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1543))
+ * `PausableCrowdsale`: allows for pausers (`PauserRole`) to pause token purchases. Other crowdsale operations (e.g. withdrawals and refunds, if applicable) are not affected. ([#832](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/832))
+ * `ERC20`: `transferFrom` and `_burnFrom ` now emit `Approval` events, to represent the token's state comprehensively through events. ([#1524](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1524))
+ * `ERC721`: added `_burn(uint256 tokenId)`, replacing the similar deprecated function (see below). ([#1550](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1550))
+ * `ERC721`: added `_tokensOfOwner(address owner)`, allowing to internally retrieve the array of an account's owned tokens. ([#1522](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1522))
+ * Crowdsales: all constructors are now `public`, meaning it is not necessary to extend these contracts in order to deploy them. The exception is `FinalizableCrowdsale`, since it is meaningless unless extended. ([#1564](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1564))
+ * `SignedSafeMath`: added overflow-safe operations for signed integers (`int256`). ([#1559](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1559), [#1588](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1588))
+
+### Improvements:
+ * The compiler version required by `Array` was behind the rest of the libray so it was updated to `v0.4.24`. ([#1553](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1553))
+ * Now conforming to a 4-space indentation code style. ([1508](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1508))
+ * `ERC20`: more gas efficient due to removed redundant `require`s. ([#1409](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1409))
+ * `ERC721`: fixed a bug that prevented internal data structures from being properly cleaned, missing potential gas refunds. ([#1539](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1539) and [#1549](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1549))
+ * `ERC721`: general gas savings on `transferFrom`, `_mint` and `_burn`, due to redudant `require`s and `SSTORE`s. ([#1549](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1549))
+
+### Bugfixes:
+
+### Breaking changes:
+
+### Deprecations:
+ * `ERC721._burn(address owner, uint256 tokenId)`: due to the `owner` parameter being unnecessary. ([#1550](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1550))
+ * `RefundableCrowdsale`: due to trading abuse potential on crowdsales that miss their goal. ([#1543](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1543))

CODE_STYLE.md

@@ -16,11 +16,14 @@ Any exception or additions specific to our project are documented below.
 
 * Try to avoid acronyms and abbreviations.
 
+* All state variables should be private.
+
 * Private state variables should have an underscore prefix.
 
     ```
     contract TestContract {
       uint256 private _privateVar;
+      uint256 internal _internalVar;
     }
     ```
 

README.md

@@ -15,6 +15,24 @@ This fork of OpenZeppelin is set up as a **reusable EVM Package**. It is deploye
 npm install openzeppelin-eth
 ```
 
+## Usage
+
+To write your custom contracts, import ours and extend them through inheritance.
+
+```solidity
+pragma solidity ^0.5.0;
+
+import 'zos-lib/contracts/Initializable.sol';
+import 'openzeppelin-solidity/contracts/token/ERC721/ERC721Full.sol';
+import 'openzeppelin-solidity/contracts/token/ERC721/ERC721Mintable.sol';
+
+contract MyNFT is Initializable, ERC721Full, ERC721Mintable {
+  function initialize() public initializer {
+    ERC721Full.initialize("MyNFT", "MNFT");
+  }
+}
+```
+
 ## Pre-deployed contracts
 
 - StandaloneERC20

RELEASING.md

@@ -34,7 +34,7 @@ git push upstream vX.Y.Z-rc.R
 
 Draft the release notes in our [GitHub releases](https://github.com/OpenZeppelin/openzeppelin-solidity/releases). Make sure to mark it as a pre-release! Try to be consistent with our previous release notes in the title and format of the text. Release candidates don't need a detailed changelog, but make sure to include a link to GitHub's compare page.
 
-Once the CI run for the new tag is green, publish on npm under the `next` tag.
+Once the CI run for the new tag is green, publish on npm under the `next` tag. You should see the contracts compile automatically.
 
 ```
 npm publish --tag next
@@ -62,7 +62,7 @@ git push upstream vX.Y.Z
 
 Draft the release notes in GitHub releases. Try to be consistent with our previous release notes in the title and format of the text. Make sure to include a detailed changelog.
 
-Once the CI run for the new tag is green, publish on npm.
+Once the CI run for the new tag is green, publish on npm. You should see the contracts compile automatically.
 
 ```
 npm publish

contracts/ARCHITECTURE.md

@@ -12,7 +12,7 @@ The following provides visibility into how OpenZeppelin's contracts are organize
 - **introspection**  - An interface that can be used to make a contract comply with the ERC-165 standard as well as a contract that implements ERC-165 using a lookup table.
 - **lifecycle** - A collection of base contracts used to manage the existence and behavior of your contracts and their funds.
 - **math** - Libraries with safety checks on operations that throw on errors.
-- **mocks** - A collection of abstract contracts that are primarily used for unit testing. They also serve as good usage examples and demonstrate how to combine contracts with inheritence when developing your own custom applications.
+- **mocks** - A collection of abstract contracts that are primarily used for unit testing. They also serve as good usage examples and demonstrate how to combine contracts with inheritance when developing your own custom applications.
 - **ownership** - A collection of smart contracts that can be used to manage contract and token ownership
 - **payment** - A collection of smart contracts that can be used to manage payments through escrow arrangements, withdrawals, and claims. Includes support for both single payees and multiple payees.
 - **proposals** - A collection of smart contracts that reflect community Ethereum Improvement Proposals (EIPs). These contracts are under development and standardization. They are not recommended for production, but they are useful for experimentation with pending EIP standards. Go [here](https://github.com/OpenZeppelin/openzeppelin-solidity/wiki/ERC-Process) for more information.

contracts/access/Roles.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 /**
  * @title Roles
@@ -15,6 +14,8 @@ library Roles {
      */
     function add(Role storage role, address account) internal {
         require(account != address(0));
+        require(!has(role, account));
+
         role.bearer[account] = true;
     }
 
@@ -23,6 +24,8 @@ library Roles {
      */
     function remove(Role storage role, address account) internal {
         require(account != address(0));
+        require(has(role, account));
+
         role.bearer[account] = false;
     }
 
@@ -30,11 +33,7 @@ library Roles {
      * @dev check if an account has this role
      * @return bool
      */
-    function has(Role storage role, address account)
-        internal
-        view
-        returns (bool)
-    {
+    function has(Role storage role, address account) internal view returns (bool) {
         require(account != address(0));
         return role.bearer[account];
     }

contracts/access/roles/CapperRole.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../Roles.sol";
@@ -10,7 +10,7 @@ contract CapperRole is Initializable {
     event CapperAdded(address indexed account);
     event CapperRemoved(address indexed account);
 
-    Roles.Role private cappers;
+    Roles.Role private _cappers;
 
     function initialize(address sender) public initializer {
         if (!isCapper(sender)) {
@@ -24,7 +24,7 @@ contract CapperRole is Initializable {
     }
 
     function isCapper(address account) public view returns (bool) {
-        return cappers.has(account);
+        return _cappers.has(account);
     }
 
     function addCapper(address account) public onlyCapper {
@@ -36,12 +36,12 @@ contract CapperRole is Initializable {
     }
 
     function _addCapper(address account) internal {
-        cappers.add(account);
+        _cappers.add(account);
         emit CapperAdded(account);
     }
 
     function _removeCapper(address account) internal {
-        cappers.remove(account);
+        _cappers.remove(account);
         emit CapperRemoved(account);
     }
 

contracts/access/roles/MinterRole.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../Roles.sol";
@@ -10,7 +10,7 @@ contract MinterRole is Initializable {
     event MinterAdded(address indexed account);
     event MinterRemoved(address indexed account);
 
-    Roles.Role private minters;
+    Roles.Role private _minters;
 
     function initialize(address sender) public initializer {
         if (!isMinter(sender)) {
@@ -24,7 +24,7 @@ contract MinterRole is Initializable {
     }
 
     function isMinter(address account) public view returns (bool) {
-        return minters.has(account);
+        return _minters.has(account);
     }
 
     function addMinter(address account) public onlyMinter {
@@ -36,12 +36,12 @@ contract MinterRole is Initializable {
     }
 
     function _addMinter(address account) internal {
-        minters.add(account);
+        _minters.add(account);
         emit MinterAdded(account);
     }
 
     function _removeMinter(address account) internal {
-        minters.remove(account);
+        _minters.remove(account);
         emit MinterRemoved(account);
     }
 

contracts/access/roles/PauserRole.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../Roles.sol";
@@ -10,7 +10,7 @@ contract PauserRole is Initializable {
     event PauserAdded(address indexed account);
     event PauserRemoved(address indexed account);
 
-    Roles.Role private pausers;
+    Roles.Role private _pausers;
 
     function initialize(address sender) public initializer {
         if (!isPauser(sender)) {
@@ -24,7 +24,7 @@ contract PauserRole is Initializable {
     }
 
     function isPauser(address account) public view returns (bool) {
-        return pausers.has(account);
+        return _pausers.has(account);
     }
 
     function addPauser(address account) public onlyPauser {
@@ -36,12 +36,12 @@ contract PauserRole is Initializable {
     }
 
     function _addPauser(address account) internal {
-        pausers.add(account);
+        _pausers.add(account);
         emit PauserAdded(account);
     }
 
     function _removePauser(address account) internal {
-        pausers.remove(account);
+        _pausers.remove(account);
         emit PauserRemoved(account);
     }
 

contracts/access/roles/SignerRole.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../Roles.sol";
@@ -10,7 +10,7 @@ contract SignerRole is Initializable {
     event SignerAdded(address indexed account);
     event SignerRemoved(address indexed account);
 
-    Roles.Role private signers;
+    Roles.Role private _signers;
 
     function initialize(address sender) public initializer {
         if (!isSigner(sender)) {
@@ -24,7 +24,7 @@ contract SignerRole is Initializable {
     }
 
     function isSigner(address account) public view returns (bool) {
-        return signers.has(account);
+        return _signers.has(account);
     }
 
     function addSigner(address account) public onlySigner {
@@ -36,12 +36,12 @@ contract SignerRole is Initializable {
     }
 
     function _addSigner(address account) internal {
-        signers.add(account);
+        _signers.add(account);
         emit SignerAdded(account);
     }
 
     function _removeSigner(address account) internal {
-        signers.remove(account);
+        _signers.remove(account);
         emit SignerRemoved(account);
     }
 

contracts/access/roles/WhitelistAdminRole.sol

+pragma solidity ^0.5.0;
+
+import "../Roles.sol";
+
+/**
+ * @title WhitelistAdminRole
+ * @dev WhitelistAdmins are responsible for assigning and removing Whitelisted accounts.
+ */
+contract WhitelistAdminRole {
+    using Roles for Roles.Role;
+
+    event WhitelistAdminAdded(address indexed account);
+    event WhitelistAdminRemoved(address indexed account);
+
+    Roles.Role private _whitelistAdmins;
+
+    constructor () internal {
+        _addWhitelistAdmin(msg.sender);
+    }
+
+    modifier onlyWhitelistAdmin() {
+        require(isWhitelistAdmin(msg.sender));
+        _;
+    }
+
+    function isWhitelistAdmin(address account) public view returns (bool) {
+        return _whitelistAdmins.has(account);
+    }
+
+    function addWhitelistAdmin(address account) public onlyWhitelistAdmin {
+        _addWhitelistAdmin(account);
+    }
+
+    function renounceWhitelistAdmin() public {
+        _removeWhitelistAdmin(msg.sender);
+    }
+
+    function _addWhitelistAdmin(address account) internal {
+        _whitelistAdmins.add(account);
+        emit WhitelistAdminAdded(account);
+    }
+
+    function _removeWhitelistAdmin(address account) internal {
+        _whitelistAdmins.remove(account);
+        emit WhitelistAdminRemoved(account);
+    }
+}

contracts/access/roles/WhitelistedRole.sol

+pragma solidity ^0.5.0;
+
+import "../Roles.sol";
+import "./WhitelistAdminRole.sol";
+
+/**
+ * @title WhitelistedRole
+ * @dev Whitelisted accounts have been approved by a WhitelistAdmin to perform certain actions (e.g. participate in a
+ * 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 WhitelistAdminRole {
+    using Roles for Roles.Role;
+
+    event WhitelistedAdded(address indexed account);
+    event WhitelistedRemoved(address indexed account);
+
+    Roles.Role private _whitelisteds;
+
+    modifier onlyWhitelisted() {
+        require(isWhitelisted(msg.sender));
+        _;
+    }
+
+    function isWhitelisted(address account) public view returns (bool) {
+        return _whitelisteds.has(account);
+    }
+
+    function addWhitelisted(address account) public onlyWhitelistAdmin {
+        _addWhitelisted(account);
+    }
+
+    function removeWhitelisted(address account) public onlyWhitelistAdmin {
+        _removeWhitelisted(account);
+    }
+
+    function renounceWhitelisted() public {
+        _removeWhitelisted(msg.sender);
+    }
+
+    function _addWhitelisted(address account) internal {
+        _whitelisteds.add(account);
+        emit WhitelistedAdded(account);
+    }
+
+    function _removeWhitelisted(address account) internal {
+        _whitelisteds.remove(account);
+        emit WhitelistedRemoved(account);
+    }
+}

contracts/crowdsale/Crowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../token/ERC20/IERC20.sol";
 import "../math/SafeMath.sol";
 import "../token/ERC20/SafeERC20.sol";
-
+import "../utils/ReentrancyGuard.sol";
 
 /**
  * @title Crowdsale
@@ -18,7 +18,7 @@ import "../token/ERC20/SafeERC20.sol";
  * the methods to add functionality. Consider using 'super' where appropriate to concatenate
  * behavior.
  */
-contract Crowdsale is Initializable {
+contract Crowdsale is Initializable, ReentrancyGuard {
     using SafeMath for uint256;
     using SafeERC20 for IERC20;
 
@@ -26,7 +26,7 @@ contract Crowdsale is Initializable {
     IERC20 private _token;
 
     // Address where funds are collected
-    address private _wallet;
+    address payable private _wallet;
 
     // How many token units a buyer gets per wei.
     // The rate is the conversion between wei and the smallest and indivisible token unit.
@@ -44,12 +44,7 @@ contract Crowdsale is Initializable {
      * @param value weis paid for purchase
      * @param amount amount of tokens purchased
      */
-    event TokensPurchased(
-        address indexed purchaser,
-        address indexed beneficiary,
-        uint256 value,
-        uint256 amount
-    );
+    event TokensPurchased(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);
 
     /**
      * @param rate Number of token units a buyer gets per wei
@@ -62,19 +57,18 @@ contract Crowdsale is Initializable {
     function initialize(uint256 rate, address wallet, IERC20 token) public initializer {
         require(rate > 0);
         require(wallet != address(0));
-        require(token != address(0));
+        require(address(token) != address(0));
 
         _rate = rate;
         _wallet = wallet;
         _token = token;
     }
 
-    // -----------------------------------------
-    // Crowdsale external interface
-    // -----------------------------------------
-
     /**
      * @dev fallback function ***DO NOT OVERRIDE***
+     * Note that other contracts will transfer fund with a base gas stipend
+     * of 2300, which is not enough to call buyTokens. Consider calling
+     * buyTokens directly when purchasing tokens from a contract.
      */
     function () external payable {
         buyTokens(msg.sender);
@@ -83,26 +77,26 @@ contract Crowdsale is Initializable {
     /**
      * @return the token being sold.
      */
-    function token() public view returns(IERC20) {
+    function token() public view returns (IERC20) {
         return _token;
     }
 
     /**
      * @return the address where funds are collected.
      */
-    function wallet() public view returns(address) {
+    function wallet() public view returns (address payable) {
         return _wallet;
     }
 
     /**
      * @return the number of token units a buyer gets per wei.
      */
-    function rate() public view returns(uint256) {
+    function rate() public view returns (uint256) {
         return _rate;
     }
 
     /**
-     * @return the mount of wei raised.
+     * @return the amount of wei raised.
      */
     function weiRaised() public view returns (uint256) {
         return _weiRaised;
@@ -110,10 +104,11 @@ contract Crowdsale is Initializable {
 
     /**
      * @dev low level token purchase ***DO NOT OVERRIDE***
-     * @param beneficiary Address performing the token purchase
+     * This function has a non-reentrancy guard, so it shouldn't be called by
+     * another `nonReentrant` function.
+     * @param beneficiary Recipient of the token purchase
      */
-    function buyTokens(address beneficiary) public payable {
-
+    function buyTokens(address beneficiary) public nonReentrant payable {
         uint256 weiAmount = msg.value;
         _preValidatePurchase(beneficiary, weiAmount);
 
@@ -124,12 +119,7 @@ contract Crowdsale is Initializable {
         _weiRaised = _weiRaised.add(weiAmount);
 
         _processPurchase(beneficiary, tokens);
-        emit TokensPurchased(
-            msg.sender,
-            beneficiary,
-            weiAmount,
-            tokens
-        );
+        emit TokensPurchased(msg.sender, beneficiary, weiAmount, tokens);
 
         _updatePurchasingState(beneficiary, weiAmount);
 
@@ -137,86 +127,62 @@ contract Crowdsale is Initializable {
         _postValidatePurchase(beneficiary, weiAmount);
     }
 
-    // -----------------------------------------
-    // Internal interface (extensible)
-    // -----------------------------------------
-
     function _hasBeenInitialized() internal view returns (bool) {
         return ((_rate > 0) && (_wallet != address(0)) && (_token != address(0)));
     }
 
     /**
-     * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met. Use `super` in contracts that inherit from Crowdsale to extend their validations.
+     * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met.
+     * Use `super` in contracts that inherit from Crowdsale to extend their validations.
      * Example from CappedCrowdsale.sol's _preValidatePurchase method:
-     *   super._preValidatePurchase(beneficiary, weiAmount);
-     *   require(weiRaised().add(weiAmount) <= cap);
+     *     super._preValidatePurchase(beneficiary, weiAmount);
+     *     require(weiRaised().add(weiAmount) <= cap);
      * @param beneficiary Address performing the token purchase
      * @param weiAmount Value in wei involved in the purchase
      */
-    function _preValidatePurchase(
-        address beneficiary,
-        uint256 weiAmount
-    )
-        internal
-    {
+    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
         require(beneficiary != address(0));
         require(weiAmount != 0);
     }
 
     /**
-     * @dev Validation of an executed purchase. Observe state and use revert statements to undo rollback when valid conditions are not met.
+     * @dev Validation of an executed purchase. Observe state and use revert statements to undo rollback when valid
+     * conditions are not met.
      * @param beneficiary Address performing the token purchase
      * @param weiAmount Value in wei involved in the purchase
      */
-    function _postValidatePurchase(
-        address beneficiary,
-        uint256 weiAmount
-    )
-        internal
-    {
-        // optional override
+    function _postValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
+        // solhint-disable-previous-line no-empty-blocks
     }
 
     /**
-     * @dev Source of tokens. Override this method to modify the way in which the crowdsale ultimately gets and sends its tokens.
+     * @dev Source of tokens. Override this method to modify the way in which the crowdsale ultimately gets and sends
+     * its tokens.
      * @param beneficiary Address performing the token purchase
      * @param tokenAmount Number of tokens to be emitted
      */
-    function _deliverTokens(
-        address beneficiary,
-        uint256 tokenAmount
-    )
-        internal
-    {
+    function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
         _token.safeTransfer(beneficiary, tokenAmount);
     }
 
     /**
-     * @dev Executed when a purchase has been validated and is ready to be executed. Not necessarily emits/sends tokens.
+     * @dev Executed when a purchase has been validated and is ready to be executed. Doesn't necessarily emit/send
+     * tokens.
      * @param beneficiary Address receiving the tokens
      * @param tokenAmount Number of tokens to be purchased
      */
-    function _processPurchase(
-        address beneficiary,
-        uint256 tokenAmount
-    )
-        internal
-    {
+    function _processPurchase(address beneficiary, uint256 tokenAmount) internal {
         _deliverTokens(beneficiary, tokenAmount);
     }
 
     /**
-     * @dev Override for extensions that require an internal state to check for validity (current user contributions, etc.)
+     * @dev Override for extensions that require an internal state to check for validity (current user contributions,
+     * etc.)
      * @param beneficiary Address receiving the tokens
      * @param weiAmount Value in wei involved in the purchase
      */
-    function _updatePurchasingState(
-        address beneficiary,
-        uint256 weiAmount
-    )
-        internal
-    {
-        // optional override
+    function _updatePurchasingState(address beneficiary, uint256 weiAmount) internal {
+        // solhint-disable-previous-line no-empty-blocks
     }
 
     /**
@@ -224,9 +190,7 @@ contract Crowdsale is Initializable {
      * @param weiAmount Value in wei to be converted into tokens
      * @return Number of tokens that can be purchased with the specified _weiAmount
      */
-    function _getTokenAmount(uint256 weiAmount)
-        internal view returns (uint256)
-    {
+    function _getTokenAmount(uint256 weiAmount) internal view returns (uint256) {
         return weiAmount.mul(_rate);
     }
 

contracts/crowdsale/distribution/FinalizableCrowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../../math/SafeMath.sol";
 import "../validation/TimedCrowdsale.sol";
 
-
 /**
  * @title FinalizableCrowdsale
  * @dev Extension of Crowdsale with a one-off finalization action, where one
@@ -13,7 +12,7 @@ import "../validation/TimedCrowdsale.sol";
 contract FinalizableCrowdsale is Initializable, TimedCrowdsale {
     using SafeMath for uint256;
 
-    bool private _finalized = false;
+    bool private _finalized;
 
     event CrowdsaleFinalized();
 
@@ -32,10 +31,10 @@ contract FinalizableCrowdsale is Initializable, TimedCrowdsale {
         require(!_finalized);
         require(hasClosed());
 
+        _finalized = true;
+
         _finalization();
         emit CrowdsaleFinalized();
-
-        _finalized = true;
     }
 
     /**
@@ -44,8 +43,8 @@ contract FinalizableCrowdsale is Initializable, TimedCrowdsale {
      * executed entirely.
      */
     function _finalization() internal {
+        // solhint-disable-previous-line no-empty-blocks
     }
 
-
     uint256[50] private ______gap;
 }

contracts/crowdsale/distribution/PostDeliveryCrowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../validation/TimedCrowdsale.sol";
-import "../../token/ERC20/IERC20.sol";
 import "../../math/SafeMath.sol";
 
-
 /**
  * @title PostDeliveryCrowdsale
  * @dev Crowdsale that locks tokens from withdrawal until it ends.
@@ -30,7 +28,7 @@ contract PostDeliveryCrowdsale is Initializable, TimedCrowdsale {
     /**
      * @return the balance of an account.
      */
-    function balanceOf(address account) public view returns(uint256) {
+    function balanceOf(address account) public view returns (uint256) {
         return _balances[account];
     }
 
@@ -39,12 +37,7 @@ contract PostDeliveryCrowdsale is Initializable, TimedCrowdsale {
      * @param beneficiary Token purchaser
      * @param tokenAmount Amount of tokens purchased
      */
-    function _processPurchase(
-        address beneficiary,
-        uint256 tokenAmount
-    )
-        internal
-    {
+    function _processPurchase(address beneficiary, uint256 tokenAmount) internal {
         _balances[beneficiary] = _balances[beneficiary].add(tokenAmount);
     }
 

contracts/crowdsale/distribution/RefundableCrowdsale.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../../math/SafeMath.sol";
 import "./FinalizableCrowdsale.sol";
-import "../../payment/RefundEscrow.sol";
-
+import "../../payment/escrow/RefundEscrow.sol";
 
 /**
  * @title RefundableCrowdsale
- * @dev Extension of Crowdsale contract that adds a funding goal, and
- * the possibility of users getting a refund if goal is not met.
+ * @dev Extension of Crowdsale contract that adds a funding goal, and the possibility of users getting a refund if goal
+ * is not met.
+ *
+ * Deprecated, use RefundablePostDeliveryCrowdsale instead. Note that if you allow tokens to be traded before the goal
+ * is met, then an attack is possible in which the attacker purchases tokens from the crowdsale and when they sees that
+ * 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 {
     using SafeMath for uint256;
@@ -30,32 +33,30 @@ contract RefundableCrowdsale is Initializable, FinalizableCrowdsale {
         assert(TimedCrowdsale._hasBeenInitialized());
 
         require(goal > 0);
-
         // conditional added to make initializer idempotent in case of diamond inheritance
         if (address(_escrow) == address(0)) {
             _escrow = new RefundEscrow();
             _escrow.initialize(wallet(), address(this));
         }
-
         _goal = goal;
     }
 
     /**
      * @return minimum amount of funds to be raised in wei.
      */
-    function goal() public view returns(uint256) {
+    function goal() public view returns (uint256) {
         return _goal;
     }
 
     /**
      * @dev Investors can claim refunds here if crowdsale is unsuccessful
-     * @param beneficiary Whose refund will be claimed.
+     * @param refundee Whose refund will be claimed.
      */
-    function claimRefund(address beneficiary) public {
+    function claimRefund(address payable refundee) public {
         require(finalized());
         require(!goalReached());
 
-        _escrow.withdraw(beneficiary);
+        _escrow.withdraw(refundee);
     }
 
     /**
@@ -87,6 +88,5 @@ contract RefundableCrowdsale is Initializable, FinalizableCrowdsale {
         _escrow.deposit.value(msg.value)(msg.sender);
     }
 
-
     uint256[50] private ______gap;
 }

contracts/crowdsale/distribution/RefundablePostDeliveryCrowdsale.sol

+pragma solidity ^0.5.0;
+
+import "./RefundableCrowdsale.sol";
+import "./PostDeliveryCrowdsale.sol";
+
+
+/**
+ * @title RefundablePostDeliveryCrowdsale
+ * @dev Extension of RefundableCrowdsale contract that only delivers the tokens
+ * once the crowdsale has closed and the goal met, preventing refunds to be issued
+ * to token holders.
+ */
+contract RefundablePostDeliveryCrowdsale is RefundableCrowdsale, PostDeliveryCrowdsale {
+    function withdrawTokens(address beneficiary) public {
+        require(finalized());
+        require(goalReached());
+
+        super.withdrawTokens(beneficiary);
+    }
+}

contracts/crowdsale/emission/AllowanceCrowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../Crowdsale.sol";
 import "../../token/ERC20/IERC20.sol";
 import "../../token/ERC20/SafeERC20.sol";
 import "../../math/SafeMath.sol";
-
+import "../../math/Math.sol";
 
 /**
  * @title AllowanceCrowdsale
@@ -31,7 +31,7 @@ contract AllowanceCrowdsale is Initializable, Crowdsale {
     /**
      * @return the address of the wallet that will hold the tokens.
      */
-    function tokenWallet() public view returns(address) {
+    function tokenWallet() public view returns (address) {
         return _tokenWallet;
     }
 
@@ -40,7 +40,7 @@ contract AllowanceCrowdsale is Initializable, Crowdsale {
      * @return Amount of tokens left in the allowance
      */
     function remainingTokens() public view returns (uint256) {
-        return token().allowance(_tokenWallet, this);
+        return Math.min(token().balanceOf(_tokenWallet), token().allowance(_tokenWallet, address(this)));
     }
 
     /**
@@ -48,12 +48,7 @@ contract AllowanceCrowdsale is Initializable, Crowdsale {
      * @param beneficiary Token purchaser
      * @param tokenAmount Amount of tokens purchased
      */
-    function _deliverTokens(
-        address beneficiary,
-        uint256 tokenAmount
-    )
-        internal
-    {
+    function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
         token().safeTransferFrom(_tokenWallet, beneficiary, tokenAmount);
     }
 

contracts/crowdsale/emission/MintedCrowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../Crowdsale.sol";
 import "../../token/ERC20/ERC20Mintable.sol";
 
-
 /**
  * @title MintedCrowdsale
  * @dev Extension of Crowdsale contract whose tokens are minted in each purchase.
  * Token ownership should be transferred to MintedCrowdsale for minting.
  */
 contract MintedCrowdsale is Initializable, Crowdsale {
-
     /**
      * @dev Overrides delivery by minting tokens upon purchase.
      * @param beneficiary Token purchaser
      * @param tokenAmount Number of tokens to be minted
      */
-    function _deliverTokens(
-        address beneficiary,
-        uint256 tokenAmount
-    )
-        internal
-    {
+    function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
         // Potentially dangerous assumption about the type of the token.
-        require(
-            ERC20Mintable(address(token())).mint(beneficiary, tokenAmount));
+        require(ERC20Mintable(address(token())).mint(beneficiary, tokenAmount));
     }
 
     uint256[50] private ______gap;

contracts/crowdsale/price/IncreasingPriceCrowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../validation/TimedCrowdsale.sol";
 import "../../math/SafeMath.sol";
 
-
 /**
  * @title IncreasingPriceCrowdsale
  * @dev Extension of Crowdsale contract that increases the price of tokens linearly in time.
@@ -26,15 +25,23 @@ contract IncreasingPriceCrowdsale is Initializable, TimedCrowdsale {
         assert(TimedCrowdsale._hasBeenInitialized());
 
         require(finalRate > 0);
-        require(initialRate >= finalRate);
+        require(initialRate > finalRate);
         _initialRate = initialRate;
         _finalRate = finalRate;
     }
 
     /**
+     * The base rate function is overridden to revert, since this crowdsale doens't use it, and
+     * all calls to it are a mistake.
+     */
+    function rate() public view returns (uint256) {
+        revert();
+    }
+
+    /**
      * @return the initial rate of the crowdsale.
      */
-    function initialRate() public view returns(uint256) {
+    function initialRate() public view returns (uint256) {
         return _initialRate;
     }
 
@@ -51,7 +58,11 @@ contract IncreasingPriceCrowdsale is Initializable, TimedCrowdsale {
      * @return The number of tokens a buyer gets per wei at a given time
      */
     function getCurrentRate() public view returns (uint256) {
-        // solium-disable-next-line security/no-block-members
+        if (!isOpen()) {
+            return 0;
+        }
+
+        // solhint-disable-next-line not-rely-on-time
         uint256 elapsedTime = block.timestamp.sub(openingTime());
         uint256 timeRange = closingTime().sub(openingTime());
         uint256 rateRange = _initialRate.sub(_finalRate);
@@ -63,13 +74,10 @@ contract IncreasingPriceCrowdsale is Initializable, TimedCrowdsale {
      * @param weiAmount The value in wei to be converted into tokens
      * @return The number of tokens _weiAmount wei will buy at present time
      */
-    function _getTokenAmount(uint256 weiAmount)
-        internal view returns (uint256)
-    {
+    function _getTokenAmount(uint256 weiAmount) internal view returns (uint256) {
         uint256 currentRate = getCurrentRate();
         return currentRate.mul(weiAmount);
     }
 
-
     uint256[50] private ______gap;
 }

contracts/crowdsale/validation/CappedCrowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../../math/SafeMath.sol";
 import "../Crowdsale.sol";
 
-
 /**
  * @title CappedCrowdsale
  * @dev Crowdsale with a limit for total contributions.
@@ -28,7 +27,7 @@ contract CappedCrowdsale is Initializable, Crowdsale {
     /**
      * @return the cap of the crowdsale.
      */
-    function cap() public view returns(uint256) {
+    function cap() public view returns (uint256) {
         return _cap;
     }
 
@@ -45,16 +44,10 @@ contract CappedCrowdsale is Initializable, Crowdsale {
      * @param beneficiary Token purchaser
      * @param weiAmount Amount of wei contributed
      */
-    function _preValidatePurchase(
-        address beneficiary,
-        uint256 weiAmount
-    )
-        internal
-    {
+    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
         super._preValidatePurchase(beneficiary, weiAmount);
         require(weiRaised().add(weiAmount) <= _cap);
     }
 
-
     uint256[50] private ______gap;
 }

contracts/crowdsale/validation/IndividuallyCappedCrowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../../math/SafeMath.sol";
 import "../Crowdsale.sol";
 import "../../access/roles/CapperRole.sol";
 
-
 /**
  * @title IndividuallyCappedCrowdsale
  * @dev Crowdsale with per-beneficiary caps.
@@ -45,9 +44,7 @@ contract IndividuallyCappedCrowdsale is Initializable, Crowdsale, CapperRole {
      * @param beneficiary Address of contributor
      * @return Beneficiary contribution so far
      */
-    function getContribution(address beneficiary)
-        public view returns (uint256)
-    {
+    function getContribution(address beneficiary) public view returns (uint256) {
         return _contributions[beneficiary];
     }
 
@@ -56,15 +53,9 @@ contract IndividuallyCappedCrowdsale is Initializable, Crowdsale, CapperRole {
      * @param beneficiary Token purchaser
      * @param weiAmount Amount of wei contributed
      */
-    function _preValidatePurchase(
-        address beneficiary,
-        uint256 weiAmount
-    )
-        internal
-    {
+    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
         super._preValidatePurchase(beneficiary, weiAmount);
-        require(
-            _contributions[beneficiary].add(weiAmount) <= _caps[beneficiary]);
+        require(_contributions[beneficiary].add(weiAmount) <= _caps[beneficiary]);
     }
 
     /**
@@ -72,17 +63,10 @@ contract IndividuallyCappedCrowdsale is Initializable, Crowdsale, CapperRole {
      * @param beneficiary Token purchaser
      * @param weiAmount Amount of wei contributed
      */
-    function _updatePurchasingState(
-        address beneficiary,
-        uint256 weiAmount
-    )
-        internal
-    {
+    function _updatePurchasingState(address beneficiary, uint256 weiAmount) internal {
         super._updatePurchasingState(beneficiary, weiAmount);
-        _contributions[beneficiary] = _contributions[beneficiary].add(
-            weiAmount);
+        _contributions[beneficiary] = _contributions[beneficiary].add(weiAmount);
     }
 
-
     uint256[50] private ______gap;
 }

contracts/crowdsale/validation/PausableCrowdsale.sol

+pragma solidity ^0.5.0;
+
+import "../Crowdsale.sol";
+import "../../lifecycle/Pausable.sol";
+
+/**
+ * @title PausableCrowdsale
+ * @dev Extension of Crowdsale contract where purchases can be paused and unpaused by the pauser role.
+ */
+contract PausableCrowdsale is Crowdsale, Pausable {
+    /**
+     * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met.
+     * Use super to concatenate validations.
+     * Adds the validation that the crowdsale must not be paused.
+     * @param _beneficiary Address performing the token purchase
+     * @param _weiAmount Value in wei involved in the purchase
+     */
+    function _preValidatePurchase(address _beneficiary, uint256 _weiAmount) internal view whenNotPaused {
+        return super._preValidatePurchase(_beneficiary, _weiAmount);
+    }
+}

contracts/crowdsale/validation/TimedCrowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../../math/SafeMath.sol";
 import "../Crowdsale.sol";
 
-
 /**
  * @title TimedCrowdsale
  * @dev Crowdsale accepting contributions only within a time frame.
@@ -31,9 +30,9 @@ contract TimedCrowdsale is Initializable, Crowdsale {
     function initialize(uint256 openingTime, uint256 closingTime) public initializer {
         assert(Crowdsale._hasBeenInitialized());
 
-        // solium-disable-next-line security/no-block-members
+        // solhint-disable-next-line not-rely-on-time
         require(openingTime >= block.timestamp);
-        require(closingTime >= openingTime);
+        require(closingTime > openingTime);
 
         _openingTime = openingTime;
         _closingTime = closingTime;
@@ -42,14 +41,14 @@ contract TimedCrowdsale is Initializable, Crowdsale {
     /**
      * @return the crowdsale opening time.
      */
-    function openingTime() public view returns(uint256) {
+    function openingTime() public view returns (uint256) {
         return _openingTime;
     }
 
     /**
      * @return the crowdsale closing time.
      */
-    function closingTime() public view returns(uint256) {
+    function closingTime() public view returns (uint256) {
         return _closingTime;
     }
 
@@ -57,7 +56,7 @@ contract TimedCrowdsale is Initializable, Crowdsale {
      * @return true if the crowdsale is open, false otherwise.
      */
     function isOpen() public view returns (bool) {
-        // solium-disable-next-line security/no-block-members
+        // solhint-disable-next-line not-rely-on-time
         return block.timestamp >= _openingTime && block.timestamp <= _closingTime;
     }
 
@@ -66,7 +65,7 @@ contract TimedCrowdsale is Initializable, Crowdsale {
      * @return Whether crowdsale period has elapsed
      */
     function hasClosed() public view returns (bool) {
-        // solium-disable-next-line security/no-block-members
+        // solhint-disable-next-line not-rely-on-time
         return block.timestamp > _closingTime;
     }
 
@@ -79,16 +78,9 @@ contract TimedCrowdsale is Initializable, Crowdsale {
      * @param beneficiary Token purchaser
      * @param weiAmount Amount of wei contributed
      */
-    function _preValidatePurchase(
-        address beneficiary,
-        uint256 weiAmount
-    )
-        internal
-        onlyWhileOpen
-    {
+    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal onlyWhileOpen view {
         super._preValidatePurchase(beneficiary, weiAmount);
     }
 
-
     uint256[50] private ______gap;
 }

contracts/crowdsale/validation/WhitelistCrowdsale.sol

+pragma solidity ^0.5.0;
+import "../Crowdsale.sol";
+import "../../access/roles/WhitelistedRole.sol";
+
+
+/**
+ * @title WhitelistCrowdsale
+ * @dev Crowdsale in which only whitelisted users can contribute.
+ */
+contract WhitelistCrowdsale is WhitelistedRole, Crowdsale {
+    /**
+    * @dev Extend parent behavior requiring beneficiary to be whitelisted. Note that no
+    * restriction is imposed on the account sending the transaction.
+    * @param _beneficiary Token beneficiary
+    * @param _weiAmount Amount of wei contributed
+    */
+    function _preValidatePurchase(address _beneficiary, uint256 _weiAmount) internal view {
+        require(isWhitelisted(_beneficiary));
+        super._preValidatePurchase(_beneficiary, _weiAmount);
+    }
+}

contracts/cryptography/ECDSA.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 /**
  * @title Elliptic curve signature operations
@@ -9,17 +8,12 @@ pragma solidity ^0.4.24;
  */
 
 library ECDSA {
-
     /**
      * @dev Recover signer address from a message by using their signature
      * @param hash bytes32 message, the hash is the signed message. What is recovered is the signer address.
      * @param signature bytes signature, the signature is generated using web3.eth.sign()
      */
-    function recover(bytes32 hash, bytes signature)
-        internal
-        pure
-        returns (address)
-    {
+    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
         bytes32 r;
         bytes32 s;
         uint8 v;
@@ -32,11 +26,11 @@ library ECDSA {
         // Divide the signature in r, s and v variables
         // ecrecover takes the signature parameters, and the only way to get them
         // currently is to use assembly.
-        // solium-disable-next-line security/no-inline-assembly
+        // solhint-disable-next-line no-inline-assembly
         assembly {
-            r := mload(add(signature, 32))
-            s := mload(add(signature, 64))
-            v := byte(0, mload(add(signature, 96)))
+            r := mload(add(signature, 0x20))
+            s := mload(add(signature, 0x40))
+            v := byte(0, mload(add(signature, 0x60)))
         }
 
         // Version of signature should be 27 or 28, but 0 and 1 are also possible versions
@@ -48,7 +42,6 @@ library ECDSA {
         if (v != 27 && v != 28) {
             return (address(0));
         } else {
-            // solium-disable-next-line arg-overflow
             return ecrecover(hash, v, r, s);
         }
     }
@@ -58,15 +51,9 @@ library ECDSA {
      * @dev prefix a bytes32 value with "\x19Ethereum Signed Message:"
      * and hash the result
      */
-    function toEthSignedMessageHash(bytes32 hash)
-        internal
-        pure
-        returns (bytes32)
-    {
+    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
         // 32 is the length in bytes of hash,
         // enforced by the type signature above
-        return keccak256(
-            abi.encodePacked("\x19Ethereum Signed Message:\n32", hash)
-        );
+        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
     }
 }

contracts/cryptography/MerkleProof.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 /**
  * @title MerkleProof
@@ -14,15 +13,7 @@ library MerkleProof {
      * @param root Merkle root
      * @param leaf Leaf of Merkle tree
      */
-    function verify(
-        bytes32[] proof,
-        bytes32 root,
-        bytes32 leaf
-    )
-        internal
-        pure
-        returns (bool)
-    {
+    function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
         bytes32 computedHash = leaf;
 
         for (uint256 i = 0; i < proof.length; i++) {

contracts/drafts/Counter.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 /**
  * @title Counter
@@ -14,15 +13,11 @@ pragma solidity ^0.4.24;
  * so it's not something you have to worry about.)
  */
 library Counter {
-
     struct Counter {
         uint256 current; // default: 0
     }
 
-    function next(Counter storage index)
-        internal
-        returns (uint256)
-    {
+    function next(Counter storage index) internal returns (uint256) {
         index.current += 1;
         return index.current;
     }

contracts/drafts/ERC1046/TokenMetadata.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../../token/ERC20/IERC20.sol";
 
-
 /**
  * @title ERC-1047 Token Metadata
  * @dev See https://eips.ethereum.org/EIPS/eip-1046
  * @dev tokenURI must respond with a URI that implements https://eips.ethereum.org/EIPS/eip-1047
- * @dev TODO - update https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/token/ERC721/IERC721.sol#L17 when 1046 is finalized
  */
 contract ERC20TokenMetadata is Initializable, IERC20 {
-    function tokenURI() external view returns (string);
+    function tokenURI() external view returns (string memory);
 
     uint256[50] private ______gap;
 }
 
-
 contract ERC20WithMetadata is Initializable, ERC20TokenMetadata {
-    string private _tokenURI = "";
+    string private _tokenURI;
 
-    function initialize(string tokenURI)
-        public
-        initializer
-    {
+    function initialize(string memory tokenURI) public {
         _tokenURI = tokenURI;
     }
 
-    function tokenURI() external view returns (string) {
+    function tokenURI() external view returns (string memory) {
         return _tokenURI;
     }
 

contracts/drafts/ERC20Migrator.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../token/ERC20/IERC20.sol";
@@ -6,7 +6,6 @@ import "../token/ERC20/ERC20Mintable.sol";
 import "../token/ERC20/SafeERC20.sol";
 import "../math/Math.sol";
 
-
 /**
  * @title ERC20Migrator
  * @dev This contract can be used to migrate an ERC20 token from one
@@ -46,7 +45,7 @@ contract ERC20Migrator is Initializable {
      * @param legacyToken address of the old token contract
      */
     function initialize(IERC20 legacyToken) public initializer {
-        require(legacyToken != address(0));
+        require(address(legacyToken) != address(0));
         _legacyToken = legacyToken;
     }
 
@@ -70,9 +69,9 @@ contract ERC20Migrator is Initializable {
      * @param newToken the token that will be minted
      */
     function beginMigration(ERC20Mintable newToken) public {
-        require(_newToken == address(0));
-        require(newToken != address(0));
-        require(newToken.isMinter(this));
+        require(address(_newToken) == address(0));
+        require(address(newToken) != address(0));
+        require(newToken.isMinter(address(this)));
 
         _newToken = newToken;
     }
@@ -84,7 +83,7 @@ contract ERC20Migrator is Initializable {
      * @param amount amount of tokens to be migrated
      */
     function migrate(address account, uint256 amount) public {
-        _legacyToken.safeTransferFrom(account, this, amount);
+        _legacyToken.safeTransferFrom(account, address(this), amount);
         _newToken.mint(account, amount);
     }
 
@@ -95,7 +94,7 @@ contract ERC20Migrator is Initializable {
      */
     function migrateAll(address account) public {
         uint256 balance = _legacyToken.balanceOf(account);
-        uint256 allowance = _legacyToken.allowance(account, this);
+        uint256 allowance = _legacyToken.allowance(account, address(this));
         uint256 amount = Math.min(balance, allowance);
         migrate(account, amount);
     }

contracts/drafts/SignatureBouncer.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../access/roles/SignerRole.sol";
 import "../cryptography/ECDSA.sol";
 
-
 /**
  * @title SignatureBouncer
  * @author PhABC, Shrugs and aflesher
- * @dev SignatureBouncer allows users to submit a signature as a permission to do an action.
- * If the signature is from one of the authorized signer addresses, the signature
- * is valid.
+ * @dev SignatureBouncer allows users to submit a signature as a permission to
+ * do an action.
+ * If the signature is from one of the authorized signer addresses, the
+ * signature is valid.
+ * Note that SignatureBouncer offers no protection against replay attacks, users
+ * must add this themselves!
+ *
  * Signer addresses can be individual servers signing grants or different
- * users within a decentralized club that have permission to invite other members.
- * This technique is useful for whitelists and airdrops; instead of putting all
- * valid addresses on-chain, simply sign a grant of the form
- * keccak256(abi.encodePacked(`:contractAddress` + `:granteeAddress`)) using a valid signer address.
+ * users within a decentralized club that have permission to invite other
+ * members. This technique is useful for whitelists and airdrops; instead of
+ * putting all valid addresses on-chain, simply sign a grant of the form
+ * keccak256(abi.encodePacked(`:contractAddress` + `:granteeAddress`)) using a
+ * valid signer address.
  * Then restrict access to your crowdsale/whitelist/airdrop using the
  * `onlyValidSignature` modifier (or implement your own using _isValidSignature).
  * In addition to `onlyValidSignature`, `onlyValidSignatureAndMethod` and
- * `onlyValidSignatureAndData` can be used to restrict access to only a given method
- * or a given method with given parameters respectively.
+ * `onlyValidSignatureAndData` can be used to restrict access to only a given
+ * method or a given method with given parameters respectively.
  * See the tests in SignatureBouncer.test.js for specific usage examples.
- * @notice A method that uses the `onlyValidSignatureAndData` modifier must make the _signature
- * parameter the "last" parameter. You cannot sign a message that has its own
- * signature in it so the last 128 bytes of msg.data (which represents the
- * length of the _signature data and the _signaature data itself) is ignored when validating.
- * Also non fixed sized parameters make constructing the data in the signature
- * much more complex. See https://ethereum.stackexchange.com/a/50616 for more details.
+ *
+ * @notice A method that uses the `onlyValidSignatureAndData` modifier must make
+ * the _signature parameter the "last" parameter. You cannot sign a message that
+ * has its own signature in it so the last 128 bytes of msg.data (which
+ * represents the length of the _signature data and the _signaature data itself)
+ * is ignored when validating. Also non fixed sized parameters make constructing
+ * the data in the signature much more complex.
+ * See https://ethereum.stackexchange.com/a/50616 for more details.
  */
 contract SignatureBouncer is Initializable, SignerRole {
     using ECDSA for bytes32;
@@ -38,11 +44,14 @@ contract SignatureBouncer is Initializable, SignerRole {
     // Signature size is 65 bytes (tightly packed v + r + s), but gets padded to 96 bytes
     uint256 private constant _SIGNATURE_SIZE = 96;
 
+    function initialize(address sender) internal initializer {
+        SignerRole.initialize(sender);
+    }
+
     /**
      * @dev requires that a valid signature of a signer was provided
      */
-    modifier onlyValidSignature(bytes signature)
-    {
+    modifier onlyValidSignature(bytes memory signature) {
         require(_isValidSignature(msg.sender, signature));
         _;
     }
@@ -50,8 +59,7 @@ contract SignatureBouncer is Initializable, SignerRole {
     /**
      * @dev requires that a valid signature with a specifed method of a signer was provided
      */
-    modifier onlyValidSignatureAndMethod(bytes signature)
-    {
+    modifier onlyValidSignatureAndMethod(bytes memory signature) {
         require(_isValidSignatureAndMethod(msg.sender, signature));
         _;
     }
@@ -59,48 +67,29 @@ contract SignatureBouncer is Initializable, SignerRole {
     /**
      * @dev requires that a valid signature with a specifed method and params of a signer was provided
      */
-    modifier onlyValidSignatureAndData(bytes signature)
-    {
+    modifier onlyValidSignatureAndData(bytes memory signature) {
         require(_isValidSignatureAndData(msg.sender, signature));
         _;
     }
 
-    function initialize(address sender) public initializer {
-        SignerRole.initialize(sender);
-    }
-
     /**
      * @dev is the signature of `this + sender` from a signer?
      * @return bool
      */
-    function _isValidSignature(address account, bytes signature)
-        internal
-        view
-        returns (bool)
-    {
-        return _isValidDataHash(
-            keccak256(abi.encodePacked(address(this), account)),
-            signature
-        );
+    function _isValidSignature(address account, bytes memory signature) internal view returns (bool) {
+        return _isValidDataHash(keccak256(abi.encodePacked(address(this), account)), signature);
     }
 
     /**
      * @dev is the signature of `this + sender + methodId` from a signer?
      * @return bool
      */
-    function _isValidSignatureAndMethod(address account, bytes signature)
-        internal
-        view
-        returns (bool)
-    {
+    function _isValidSignatureAndMethod(address account, bytes memory signature) internal view returns (bool) {
         bytes memory data = new bytes(_METHOD_ID_SIZE);
         for (uint i = 0; i < data.length; i++) {
             data[i] = msg.data[i];
         }
-        return _isValidDataHash(
-            keccak256(abi.encodePacked(address(this), account, data)),
-            signature
-        );
+        return _isValidDataHash(keccak256(abi.encodePacked(address(this), account, data)), signature);
     }
 
     /**
@@ -108,20 +97,15 @@ contract SignatureBouncer is Initializable, SignerRole {
         * @notice the signature parameter of the method being validated must be the "last" parameter
         * @return bool
         */
-    function _isValidSignatureAndData(address account, bytes signature)
-        internal
-        view
-        returns (bool)
-    {
+    function _isValidSignatureAndData(address account, bytes memory signature) internal view returns (bool) {
         require(msg.data.length > _SIGNATURE_SIZE);
+
         bytes memory data = new bytes(msg.data.length - _SIGNATURE_SIZE);
         for (uint i = 0; i < data.length; i++) {
             data[i] = msg.data[i];
         }
-        return _isValidDataHash(
-            keccak256(abi.encodePacked(address(this), account, data)),
-            signature
-        );
+
+        return _isValidDataHash(keccak256(abi.encodePacked(address(this), account, data)), signature);
     }
 
     /**
@@ -129,14 +113,8 @@ contract SignatureBouncer is Initializable, SignerRole {
      * and then recover the signature and check it against the signer role
      * @return bool
      */
-    function _isValidDataHash(bytes32 hash, bytes signature)
-        internal
-        view
-        returns (bool)
-    {
-        address signer = hash
-            .toEthSignedMessageHash()
-            .recover(signature);
+    function _isValidDataHash(bytes32 hash, bytes memory signature) internal view returns (bool) {
+        address signer = hash.toEthSignedMessageHash().recover(signature);
 
         return signer != address(0) && isSigner(signer);
     }

contracts/drafts/SignedSafeMath.sol

+pragma solidity ^0.5.0;
+
+/**
+ * @title SignedSafeMath
+ * @dev Signed math operations with safety checks that revert on error
+ */
+library SignedSafeMath {
+    int256 constant private INT256_MIN = -2**255;
+
+    /**
+    * @dev Multiplies two signed integers, reverts on overflow.
+    */
+    function mul(int256 a, int256 b) internal pure returns (int256) {
+        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
+        // benefit is lost if 'b' is also tested.
+        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
+        if (a == 0) {
+            return 0;
+        }
+
+        require(!(a == -1 && b == INT256_MIN)); // This is the only case of overflow not detected by the check below
+
+        int256 c = a * b;
+        require(c / a == b);
+
+        return c;
+    }
+
+    /**
+    * @dev Integer division of two signed integers truncating the quotient, reverts on division by zero.
+    */
+    function div(int256 a, int256 b) internal pure returns (int256) {
+        require(b != 0); // Solidity only automatically asserts when dividing by 0
+        require(!(b == -1 && a == INT256_MIN)); // This is the only case of overflow
+
+        int256 c = a / b;
+
+        return c;
+    }
+
+    /**
+    * @dev Subtracts two signed integers, reverts on overflow.
+    */
+    function sub(int256 a, int256 b) internal pure returns (int256) {
+        int256 c = a - b;
+        require((b >= 0 && c <= a) || (b < 0 && c > a));
+
+        return c;
+    }
+
+    /**
+    * @dev Adds two signed integers, reverts on overflow.
+    */
+    function add(int256 a, int256 b) internal pure returns (int256) {
+        int256 c = a + b;
+        require((b >= 0 && c >= a) || (b < 0 && c < a));
+
+        return c;
+    }
+}

contracts/drafts/TokenVesting.sol

-/* solium-disable security/no-block-members */
-
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../token/ERC20/SafeERC20.sol";
 import "../ownership/Ownable.sol";
 import "../math/SafeMath.sol";
 
-
 /**
  * @title TokenVesting
  * @dev A token holder contract that can release its token balance gradually like a
@@ -15,15 +12,22 @@ import "../math/SafeMath.sol";
  * owner.
  */
 contract TokenVesting is Initializable, Ownable {
+    // The vesting schedule is time-based (i.e. using block timestamps as opposed to e.g. block numbers), and is
+    // therefore sensitive to timestamp manipulation (which is something miners can do, to a certain degree). Therefore,
+    // it is recommended to avoid using short time durations (less than a minute). Typical vesting schemes, with a cliff
+    // period of a year and a duration of four years, are safe to use.
+    // solhint-disable not-rely-on-time
+
     using SafeMath for uint256;
     using SafeERC20 for IERC20;
 
-    event Released(uint256 amount);
-    event Revoked();
+    event TokensReleased(address token, uint256 amount);
+    event TokenVestingRevoked(address token);
 
     // beneficiary of tokens after they are released
     address private _beneficiary;
 
+    // Durations and timestamps are expressed in UNIX time, the same units as block.timestamp.
     uint256 private _cliff;
     uint256 private _start;
     uint256 private _duration;
@@ -43,21 +47,13 @@ contract TokenVesting is Initializable, Ownable {
      * @param duration duration in seconds of the period in which the tokens will vest
      * @param revocable whether the vesting is revocable or not
      */
-    function initialize(
-        address beneficiary,
-        uint256 start,
-        uint256 cliffDuration,
-        uint256 duration,
-        bool revocable,
-        address sender
-    )
-        public
-        initializer
-    {
+    constructor (address beneficiary, uint256 start, uint256 cliffDuration, uint256 duration, bool revocable, address sender) public initializer {
         Ownable.initialize(sender);
 
         require(beneficiary != address(0));
         require(cliffDuration <= duration);
+        require(duration > 0);
+        require(start.add(duration) > block.timestamp);
 
         _beneficiary = beneficiary;
         _revocable = revocable;
@@ -69,49 +65,49 @@ contract TokenVesting is Initializable, Ownable {
     /**
      * @return the beneficiary of the tokens.
      */
-    function beneficiary() public view returns(address) {
+    function beneficiary() public view returns (address) {
         return _beneficiary;
     }
 
     /**
      * @return the cliff time of the token vesting.
      */
-    function cliff() public view returns(uint256) {
+    function cliff() public view returns (uint256) {
         return _cliff;
     }
 
     /**
      * @return the start time of the token vesting.
      */
-    function start() public view returns(uint256) {
+    function start() public view returns (uint256) {
         return _start;
     }
 
     /**
      * @return the duration of the token vesting.
      */
-    function duration() public view returns(uint256) {
+    function duration() public view returns (uint256) {
         return _duration;
     }
 
     /**
      * @return true if the vesting is revocable.
      */
-    function revocable() public view returns(bool) {
+    function revocable() public view returns (bool) {
         return _revocable;
     }
 
     /**
      * @return the amount of the token released.
      */
-    function released(address token) public view returns(uint256) {
+    function released(address token) public view returns (uint256) {
         return _released[token];
     }
 
     /**
      * @return true if the token is revoked.
      */
-    function revoked(address token) public view returns(bool) {
+    function revoked(address token) public view returns (bool) {
         return _revoked[token];
     }
 
@@ -120,15 +116,15 @@ contract TokenVesting is Initializable, Ownable {
      * @param token ERC20 token which is being vested
      */
     function release(IERC20 token) public {
-        uint256 unreleased = releasableAmount(token);
+        uint256 unreleased = _releasableAmount(token);
 
         require(unreleased > 0);
 
-        _released[token] = _released[token].add(unreleased);
+        _released[address(token)] = _released[address(token)].add(unreleased);
 
         token.safeTransfer(_beneficiary, unreleased);
 
-        emit Released(unreleased);
+        emit TokensReleased(address(token), unreleased);
     }
 
     /**
@@ -138,39 +134,39 @@ contract TokenVesting is Initializable, Ownable {
      */
     function revoke(IERC20 token) public onlyOwner {
         require(_revocable);
-        require(!_revoked[token]);
+        require(!_revoked[address(token)]);
 
         uint256 balance = token.balanceOf(address(this));
 
-        uint256 unreleased = releasableAmount(token);
+        uint256 unreleased = _releasableAmount(token);
         uint256 refund = balance.sub(unreleased);
 
-        _revoked[token] = true;
+        _revoked[address(token)] = true;
 
         token.safeTransfer(owner(), refund);
 
-        emit Revoked();
+        emit TokenVestingRevoked(address(token));
     }
 
     /**
      * @dev Calculates the amount that has already vested but hasn't been released yet.
      * @param token ERC20 token which is being vested
      */
-    function releasableAmount(IERC20 token) public view returns (uint256) {
-        return vestedAmount(token).sub(_released[token]);
+    function _releasableAmount(IERC20 token) private view returns (uint256) {
+        return _vestedAmount(token).sub(_released[address(token)]);
     }
 
     /**
      * @dev Calculates the amount that has already vested.
      * @param token ERC20 token which is being vested
      */
-    function vestedAmount(IERC20 token) public view returns (uint256) {
-        uint256 currentBalance = token.balanceOf(this);
-        uint256 totalBalance = currentBalance.add(_released[token]);
+    function _vestedAmount(IERC20 token) private view returns (uint256) {
+        uint256 currentBalance = token.balanceOf(address(this));
+        uint256 totalBalance = currentBalance.add(_released[address(token)]);
 
         if (block.timestamp < _cliff) {
             return 0;
-        } else if (block.timestamp >= _start.add(_duration) || _revoked[token]) {
+        } else if (block.timestamp >= _start.add(_duration) || _revoked[address(token)]) {
             return totalBalance;
         } else {
             return totalBalance.mul(block.timestamp.sub(_start)).div(_duration);

contracts/examples/SampleCrowdsale.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../crowdsale/validation/CappedCrowdsale.sol";
 import "../crowdsale/distribution/RefundableCrowdsale.sol";
 import "../crowdsale/emission/MintedCrowdsale.sol";
 import "../token/ERC20/ERC20Mintable.sol";
-
+import "../token/ERC20/ERC20Detailed.sol";
 
 /**
  * @title SampleCrowdsaleToken
  * @dev Very simple ERC20 Token that can be minted.
  * It is meant to be used in a crowdsale contract.
  */
-contract SampleCrowdsaleToken is Initializable, ERC20Mintable {
-
-    string public name;
-    string public symbol;
-    uint8 public decimals;
-
+contract SampleCrowdsaleToken is Initializable, ERC20Mintable, ERC20Detailed {
     function initialize(address sender) public initializer {
         ERC20Mintable.initialize(sender);
-
-        name = "Sample Crowdsale Token";
-        symbol = "SCT";
-        decimals = 18;
+        ERC20Detailed.initialize("Sample Crowdsale Token", "SCT", 18);
     }
 
     uint256[50] private ______gap;
 }
 
-
 /**
  * @title SampleCrowdsale
  * @dev This is an example of a fully fledged crowdsale.
@@ -37,22 +28,19 @@ contract SampleCrowdsaleToken is Initializable, ERC20Mintable {
  * In this example we are providing following extensions:
  * CappedCrowdsale - sets a max boundary for raised funds
  * RefundableCrowdsale - set a min goal to be reached and returns funds if it's not met
+ * MintedCrowdsale - assumes the token can be minted by the crowdsale, which does so
+ * when receiving purchases.
  *
  * After adding multiple features it's good practice to run integration tests
  * to ensure that subcontracts works together as intended.
  */
-// XXX There doesn't seem to be a way to split this line that keeps solium
-// happy. See:
-// https://github.com/duaraghav8/Solium/issues/205
-// --elopio - 2018-05-10
-// solium-disable-next-line max-len
 contract SampleCrowdsale is Initializable, Crowdsale, CappedCrowdsale, RefundableCrowdsale, MintedCrowdsale {
 
     function initialize(
         uint256 openingTime,
         uint256 closingTime,
         uint256 rate,
-        address wallet,
+        address payable wallet,
         uint256 cap,
         ERC20Mintable token,
         uint256 goal

contracts/examples/SimpleToken.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "../token/ERC20/ERC20.sol";
-
+import "../token/ERC20/ERC20Detailed.sol";
 
 /**
  * @title SimpleToken
@@ -11,21 +10,17 @@ import "../token/ERC20/ERC20.sol";
  * Note they can later distribute these tokens as they wish using `transfer` and other
  * `ERC20` functions.
  */
-contract SimpleToken is Initializable, ERC20 {
-
-    string public constant name = "SimpleToken";
-    string public constant symbol = "SIM";
-    uint8 public constant decimals = 18;
-
-    uint256 public constant INITIAL_SUPPLY = 10000 * (10 ** uint256(decimals));
+contract SimpleToken is Initializable, ERC20, ERC20Detailed {
+    uint8 public constant DECIMALS = 18;
+    uint256 public constant INITIAL_SUPPLY = 10000 * (10 ** uint256(DECIMALS));
 
     /**
-     * @dev Constructor that gives sender all of existing tokens.
+     * @dev Constructor that gives msg.sender all of existing tokens.
      */
     function initialize(address sender) public initializer {
-        _mint(sender, INITIAL_SUPPLY);
+        ERC20Detailed.initialize("SimpleToken", "SIM", DECIMALS);
+        _mint(msg.sender, INITIAL_SUPPLY);
     }
 
-
     uint256[50] private ______gap;
 }

contracts/introspection/ERC165.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.sol";
 import "./IERC165.sol";
 
-
 /**
  * @title ERC165
  * @author Matt Condon (@shrugs)
  * @dev Implements ERC165 using a lookup table.
  */
 contract ERC165 is Initializable, IERC165 {
-
-    bytes4 private constant _InterfaceId_ERC165 = 0x01ffc9a7;
+    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
     /**
      * 0x01ffc9a7 ===
-     *   bytes4(keccak256('supportsInterface(bytes4)'))
+     *     bytes4(keccak256('supportsInterface(bytes4)'))
      */
 
     /**
      * @dev a mapping of interface id to whether or not it's supported
      */
-    mapping(bytes4 => bool) internal _supportedInterfaces;
+    mapping(bytes4 => bool) private _supportedInterfaces;
 
     /**
      * @dev A contract implementing SupportsInterfaceWithLookup
      * implement ERC165 itself
      */
-    function initialize()
-        public
-        initializer
-    {
+    function initialize() public initializer {
         _registerInterface(_InterfaceId_ERC165);
     }
 
     /**
      * @dev implement supportsInterface(bytes4) using a lookup table
      */
-    function supportsInterface(bytes4 interfaceId)
-        public
-        view
-        returns (bool)
-    {
+    function supportsInterface(bytes4 interfaceId) external view returns (bool) {
         return _supportedInterfaces[interfaceId];
     }
 
     /**
-     * @dev private method for registering an interface
+     * @dev internal method for registering an interface
      */
-    function _registerInterface(bytes4 interfaceId)
-        internal
-    {
+    function _registerInterface(bytes4 interfaceId) internal {
         require(interfaceId != 0xffffffff);
         _supportedInterfaces[interfaceId] = true;
     }

contracts/introspection/ERC165Checker.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 /**
  * @title ERC165Checker
@@ -8,29 +7,24 @@ pragma solidity ^0.4.24;
  */
 library ERC165Checker {
     // As per the EIP-165 spec, no interface should ever match 0xffffffff
-    bytes4 private constant _InterfaceId_Invalid = 0xffffffff;
+    bytes4 private constant _INTERFACE_ID_INVALID = 0xffffffff;
 
-    bytes4 private constant _InterfaceId_ERC165 = 0x01ffc9a7;
+    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
     /**
      * 0x01ffc9a7 ===
-     *   bytes4(keccak256('supportsInterface(bytes4)'))
+     *     bytes4(keccak256('supportsInterface(bytes4)'))
      */
 
-
     /**
      * @notice Query if a contract supports ERC165
      * @param account The address of the contract to query for support of ERC165
      * @return true if the contract at account implements ERC165
      */
-    function supportsERC165(address account)
-        internal
-        view
-        returns (bool)
-    {
+    function _supportsERC165(address account) internal view returns (bool) {
         // Any contract that implements ERC165 must explicitly indicate support of
         // InterfaceId_ERC165 and explicitly indicate non-support of InterfaceId_Invalid
-        return supportsERC165Interface(account, _InterfaceId_ERC165) &&
-            !supportsERC165Interface(account, _InterfaceId_Invalid);
+        return _supportsERC165Interface(account, _INTERFACE_ID_ERC165) &&
+            !_supportsERC165Interface(account, _INTERFACE_ID_INVALID);
     }
 
     /**
@@ -41,14 +35,10 @@ library ERC165Checker {
      * identifier interfaceId, false otherwise
      * @dev Interface identification is specified in ERC-165.
      */
-    function supportsInterface(address account, bytes4 interfaceId)
-        internal
-        view
-        returns (bool)
-    {
+    function _supportsInterface(address account, bytes4 interfaceId) internal view returns (bool) {
         // query support of both ERC165 as per the spec and support of _interfaceId
-        return supportsERC165(account) &&
-            supportsERC165Interface(account, interfaceId);
+        return _supportsERC165(account) &&
+            _supportsERC165Interface(account, interfaceId);
     }
 
     /**
@@ -59,19 +49,15 @@ library ERC165Checker {
      * interfaceIds list, false otherwise
      * @dev Interface identification is specified in ERC-165.
      */
-    function supportsInterfaces(address account, bytes4[] interfaceIds)
-        internal
-        view
-        returns (bool)
-    {
+    function _supportsAllInterfaces(address account, bytes4[] memory interfaceIds) internal view returns (bool) {
         // query support of ERC165 itself
-        if (!supportsERC165(account)) {
+        if (!_supportsERC165(account)) {
             return false;
         }
 
         // query support of each interface in _interfaceIds
         for (uint256 i = 0; i < interfaceIds.length; i++) {
-            if (!supportsERC165Interface(account, interfaceIds[i])) {
+            if (!_supportsERC165Interface(account, interfaceIds[i])) {
                 return false;
             }
         }
@@ -91,15 +77,10 @@ library ERC165Checker {
      * with the `supportsERC165` method in this library.
      * Interface identification is specified in ERC-165.
      */
-    function supportsERC165Interface(address account, bytes4 interfaceId)
-        private
-        view
-        returns (bool)
-    {
+    function _supportsERC165Interface(address account, bytes4 interfaceId) private view returns (bool) {
         // success determines whether the staticcall succeeded and result determines
         // whether the contract at account indicates support of _interfaceId
-        (bool success, bool result) = callERC165SupportsInterface(
-            account, interfaceId);
+        (bool success, bool result) = _callERC165SupportsInterface(account, interfaceId);
 
         return (success && result);
     }
@@ -112,37 +93,31 @@ library ERC165Checker {
      * @return result true if the STATICCALL succeeded and the contract at account
      * indicates support of the interface with identifier interfaceId, false otherwise
      */
-    function callERC165SupportsInterface(
-        address account,
-        bytes4 interfaceId
-    )
+    function _callERC165SupportsInterface(address account, bytes4 interfaceId)
         private
         view
         returns (bool success, bool result)
     {
-        bytes memory encodedParams = abi.encodeWithSelector(
-            _InterfaceId_ERC165,
-            interfaceId
-        );
+        bytes memory encodedParams = abi.encodeWithSelector(_INTERFACE_ID_ERC165, interfaceId);
 
-        // solium-disable-next-line security/no-inline-assembly
+        // solhint-disable-next-line no-inline-assembly
         assembly {
             let encodedParams_data := add(0x20, encodedParams)
             let encodedParams_size := mload(encodedParams)
 
-            let output := mload(0x40)  // Find empty storage location using "free memory pointer"
+            let output := mload(0x40)    // Find empty storage location using "free memory pointer"
             mstore(output, 0x0)
 
             success := staticcall(
-                30000,                 // 30k gas
-                account,              // To addr
+                30000,                                 // 30k gas
+                account,                            // To addr
                 encodedParams_data,
                 encodedParams_size,
                 output,
-                0x20                   // Outputs are 32 bytes long
+                0x20                                     // Outputs are 32 bytes long
             )
 
-            result := mload(output)  // Load the result
+            result := mload(output)    // Load the result
         }
     }
 }

contracts/introspection/IERC165.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 /**
  * @title IERC165
  * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md
  */
 interface IERC165 {
-
     /**
      * @notice Query if a contract implements an interface
      * @param interfaceId The interface identifier, as specified in ERC-165
      * @dev Interface identification is specified in ERC-165. This function
      * uses less than 30,000 gas.
      */
-    function supportsInterface(bytes4 interfaceId)
-        external
-        view
-        returns (bool);
+    function supportsInterface(bytes4 interfaceId) external view returns (bool);
 }

contracts/lifecycle/Pausable.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "zos-lib/contracts/Initializable.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 {
-    event Paused();
-    event Unpaused();
+    event Paused(address account);
+    event Unpaused(address account);
 
-    bool private _paused = false;
+    bool private _paused;
 
     function initialize(address sender) public initializer {
-        PauserRole.initialize(sender);
+        _paused = false;
     }
 
     /**
      * @return true if the contract is paused, false otherwise.
      */
-    function paused() public view returns(bool) {
+    function paused() public view returns (bool) {
         return _paused;
     }
 
@@ -46,7 +45,7 @@ contract Pausable is Initializable, PauserRole {
      */
     function pause() public onlyPauser whenNotPaused {
         _paused = true;
-        emit Paused();
+        emit Paused(msg.sender);
     }
 
     /**
@@ -54,7 +53,7 @@ contract Pausable is Initializable, PauserRole {
      */
     function unpause() public onlyPauser whenPaused {
         _paused = false;
-        emit Unpaused();
+        emit Unpaused(msg.sender);
     }
 
     uint256[50] private ______gap;

contracts/math/Math.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 /**
  * @title Math
  * @dev Assorted math operations
  */
 library Math {
+    /**
+    * @dev Returns the largest of two numbers.
+    */
     function max(uint256 a, uint256 b) internal pure returns (uint256) {
         return a >= b ? a : b;
     }
 
+    /**
+    * @dev Returns the smallest of two numbers.
+    */
     function min(uint256 a, uint256 b) internal pure returns (uint256) {
         return a < b ? a : b;
     }
 
+    /**
+    * @dev Calculates the average of two numbers. Since these are integers,
+    * averages of an even and odd number cannot be represented, and will be
+    * rounded down.
+    */
     function average(uint256 a, uint256 b) internal pure returns (uint256) {
         // (a + b) / 2 can overflow, so we distribute
         return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);

contracts/math/SafeMath.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 /**
  * @title SafeMath
- * @dev Math operations with safety checks that revert on error
+ * @dev Unsigned math operations with safety checks that revert on error
  */
 library SafeMath {
-
     /**
-    * @dev Multiplies two numbers, reverts on overflow.
+    * @dev Multiplies two unsigned integers, reverts on overflow.
     */
     function mul(uint256 a, uint256 b) internal pure returns (uint256) {
         // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
@@ -25,10 +23,11 @@ library SafeMath {
     }
 
     /**
-    * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
+    * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
     */
     function div(uint256 a, uint256 b) internal pure returns (uint256) {
-        require(b > 0); // Solidity only automatically asserts when dividing by 0
+        // Solidity only automatically asserts when dividing by 0
+        require(b > 0);
         uint256 c = a / b;
         // assert(a == b * c + a % b); // There is no case in which this doesn't hold
 
@@ -36,7 +35,7 @@ library SafeMath {
     }
 
     /**
-    * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
+    * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
     */
     function sub(uint256 a, uint256 b) internal pure returns (uint256) {
         require(b <= a);
@@ -46,7 +45,7 @@ library SafeMath {
     }
 
     /**
-    * @dev Adds two numbers, reverts on overflow.
+    * @dev Adds two unsigned integers, reverts on overflow.
     */
     function add(uint256 a, uint256 b) internal pure returns (uint256) {
         uint256 c = a + b;
@@ -56,7 +55,7 @@ library SafeMath {
     }
 
     /**
-    * @dev Divides two numbers and returns the remainder (unsigned integer modulo),
+    * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
     * reverts when dividing by zero.
     */
     function mod(uint256 a, uint256 b) internal pure returns (uint256) {

contracts/mocks/Acknowledger.sol

+pragma solidity ^0.5.0;
+
+contract Acknowledger {
+    event AcknowledgeFoo(uint256 a);
+    event AcknowledgeBarSingle(uint256 a);
+    event AcknowledgeBarDouble(uint256 a, uint256 b);
+
+    function foo(uint256 a) public {
+        emit AcknowledgeFoo(a);
+    }
+
+    function bar(uint256 a) public {
+        emit AcknowledgeBarSingle(a);
+    }
+
+    function bar(uint256 a, uint256 b) public {
+        emit AcknowledgeBarDouble(a, b);
+    }
+}

contracts/mocks/AddressImpl.sol

+pragma solidity ^0.5.0;
+
+import "../utils/Address.sol";
+
+contract AddressImpl {
+    function isContract(address account) external view returns (bool) {
+        return Address.isContract(account);
+    }
+}

contracts/mocks/AllowanceCrowdsaleImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/emission/AllowanceCrowdsale.sol";
 
-
 contract AllowanceCrowdsaleImpl is AllowanceCrowdsale {
-
-    constructor (
-        uint256 rate,
-        address wallet,
-        IERC20 token,
-        address tokenWallet
-    )
+    constructor (uint256 rate, address payable wallet, IERC20 token, address tokenWallet)
         public
     {
         Crowdsale.initialize(rate, wallet, token);
         AllowanceCrowdsale.initialize(tokenWallet);
     }
-
 }

contracts/mocks/ArraysImpl.sol

+pragma solidity ^0.5.0;
+
+import "../utils/Arrays.sol";
+
+contract ArraysImpl {
+    using Arrays for uint256[];
+
+    uint256[] private array;
+
+    constructor (uint256[] memory _array) public {
+        array = _array;
+    }
+
+    function findUpperBound(uint256 _element) external view returns (uint256) {
+        return array.findUpperBound(_element);
+    }
+}

contracts/mocks/CappedCrowdsaleImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/validation/CappedCrowdsale.sol";
 
-
 contract CappedCrowdsaleImpl is CappedCrowdsale {
-
-    constructor (
-        uint256 rate,
-        address wallet,
-        IERC20 token,
-        uint256 cap
-    )
+    constructor (uint256 rate, address payable wallet, IERC20 token, uint256 cap)
         public
     {
         Crowdsale.initialize(rate, wallet, token);
         CappedCrowdsale.initialize(cap);
     }
-
 }

contracts/mocks/CapperRoleMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/roles/CapperRole.sol";
 
-
 contract CapperRoleMock is CapperRole {
     constructor() public {
         CapperRole.initialize(msg.sender);
@@ -13,6 +12,7 @@ contract CapperRoleMock is CapperRole {
     }
 
     function onlyCapperMock() public view onlyCapper {
+        // solhint-disable-previous-line no-empty-blocks
     }
 
     // Causes a compilation error if super._removeCapper is not internal

contracts/mocks/ConditionalEscrowMock.sol

-pragma solidity ^0.4.24;
-
-import "../payment/ConditionalEscrow.sol";
+pragma solidity ^0.5.0;
 
+import "../payment/escrow/ConditionalEscrow.sol";
 
 // mock class using ConditionalEscrow
 contract ConditionalEscrowMock is ConditionalEscrow {

contracts/mocks/CounterImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../drafts/Counter.sol";
 
-
 contract CounterImpl {
     using Counter for Counter.Counter;
 
@@ -11,10 +10,7 @@ contract CounterImpl {
     // use whatever key you want to track your counters
     mapping(string => Counter.Counter) private _counters;
 
-    function doThing(string key)
-        public
-        returns (uint256)
-    {
+    function doThing(string memory key) public returns (uint256) {
         theId = _counters[key].next();
         return theId;
     }

contracts/mocks/CrowdsaleMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../crowdsale/Crowdsale.sol";
 
-
 contract CrowdsaleMock is Crowdsale {
-    constructor(uint256 rate, address wallet, IERC20 token) public {
+    constructor (uint256 rate, address payable wallet, IERC20 token) public {
         Crowdsale.initialize(rate, wallet, token);
     }
 }

contracts/mocks/DetailedERC20Mock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20.sol";
 import "../token/ERC20/ERC20Detailed.sol";
 
-
 contract ERC20DetailedMock is ERC20, ERC20Detailed {
-    constructor(
-        string name,
-        string symbol,
-        uint8 decimals
-    )
+    constructor (string memory name, string memory symbol, uint8 decimals)
         public
     {
         ERC20Detailed.initialize(name, symbol, decimals);

contracts/mocks/ECDSAMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../cryptography/ECDSA.sol";
 
-
 contract ECDSAMock {
     using ECDSA for bytes32;
 
-    function recover(bytes32 hash, bytes signature)
-        public
-        pure
-        returns (address)
-    {
+    function recover(bytes32 hash, bytes memory signature) public pure returns (address) {
         return hash.recover(signature);
     }
 
-    function toEthSignedMessageHash(bytes32 hash)
-        public
-        pure
-        returns (bytes32)
-    {
+    function toEthSignedMessageHash(bytes32 hash) public pure returns (bytes32) {
         return hash.toEthSignedMessageHash();
     }
 }

contracts/mocks/ERC165/ERC165InterfacesSupported.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../../introspection/IERC165.sol";
 
-
 /**
  * https://github.com/ethereum/EIPs/blob/master/EIPS/eip-214.md#specification
- * > Any attempts to make state-changing operations inside an execution instance with STATIC set to true will instead throw an exception.
+ * > Any attempts to make state-changing operations inside an execution instance with STATIC set to true will instead
+ * throw an exception.
  * > These operations include [...], LOG0, LOG1, LOG2, [...]
  *
  * therefore, because this contract is staticcall'd we need to not emit events (which is how solidity-coverage works)
  * solidity-coverage ignores the /mocks folder, so we duplicate its implementation here to avoid instrumenting it
  */
 contract SupportsInterfaceWithLookupMock is IERC165 {
-
-    bytes4 public constant InterfaceId_ERC165 = 0x01ffc9a7;
+    bytes4 public constant INTERFACE_ID_ERC165 = 0x01ffc9a7;
     /**
      * 0x01ffc9a7 ===
-     *   bytes4(keccak256('supportsInterface(bytes4)'))
+     *     bytes4(keccak256('supportsInterface(bytes4)'))
      */
 
     /**
      * @dev a mapping of interface id to whether or not it's supported
      */
-    mapping(bytes4 => bool) internal supportedInterfaces;
+    mapping(bytes4 => bool) private _supportedInterfaces;
 
     /**
      * @dev A contract implementing SupportsInterfaceWithLookup
      * implement ERC165 itself
      */
-    constructor()
-        public
-    {
-        _registerInterface(InterfaceId_ERC165);
+    constructor () public {
+        _registerInterface(INTERFACE_ID_ERC165);
     }
 
     /**
      * @dev implement supportsInterface(bytes4) using a lookup table
      */
-    function supportsInterface(bytes4 interfaceId)
-        external
-        view
-        returns (bool)
-    {
-        return supportedInterfaces[interfaceId];
+    function supportsInterface(bytes4 interfaceId) external view returns (bool) {
+        return _supportedInterfaces[interfaceId];
     }
 
     /**
      * @dev private method for registering an interface
      */
-    function _registerInterface(bytes4 interfaceId)
-        internal
-    {
+    function _registerInterface(bytes4 interfaceId) internal {
         require(interfaceId != 0xffffffff);
-        supportedInterfaces[interfaceId] = true;
+        _supportedInterfaces[interfaceId] = true;
     }
 }
 
-
-
 contract ERC165InterfacesSupported is SupportsInterfaceWithLookupMock {
-    constructor (bytes4[] interfaceIds)
-        public
-    {
+    constructor (bytes4[] memory interfaceIds) public {
         for (uint256 i = 0; i < interfaceIds.length; i++) {
             _registerInterface(interfaceIds[i]);
         }

contracts/mocks/ERC165/ERC165NotSupported.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 contract ERC165NotSupported {
-
+    // solhint-disable-previous-line no-empty-blocks
 }

contracts/mocks/ERC165CheckerMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../introspection/ERC165Checker.sol";
 
-
 contract ERC165CheckerMock {
     using ERC165Checker for address;
 
-    function supportsERC165(address account)
-        public
-        view
-        returns (bool)
-    {
-        return account.supportsERC165();
+    function supportsERC165(address account) public view returns (bool) {
+        return account._supportsERC165();
     }
 
-    function supportsInterface(address account, bytes4 interfaceId)
-        public
-        view
-        returns (bool)
-    {
-        return account.supportsInterface(interfaceId);
+    function supportsInterface(address account, bytes4 interfaceId) public view returns (bool) {
+        return account._supportsInterface(interfaceId);
     }
 
-    function supportsInterfaces(address account, bytes4[] interfaceIds)
-        public
-        view
-        returns (bool)
-    {
-        return account.supportsInterfaces(interfaceIds);
+    function supportsAllInterfaces(address account, bytes4[] memory interfaceIds) public view returns (bool) {
+        return account._supportsAllInterfaces(interfaceIds);
     }
 }

contracts/mocks/ERC165Mock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../introspection/ERC165.sol";
 
-
 contract ERC165Mock is ERC165 {
     constructor() public {
         ERC165.initialize();
     }
 
-    function registerInterface(bytes4 interfaceId)
-        public
-    {
+    function registerInterface(bytes4 interfaceId) public {
         _registerInterface(interfaceId);
     }
 }

contracts/mocks/ERC20BurnableMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20Burnable.sol";
 
-
 contract ERC20BurnableMock is ERC20Burnable {
-
     constructor(address initialAccount, uint256 initialBalance) public {
         _mint(initialAccount, initialBalance);
     }
-
 }

contracts/mocks/ERC20MintableMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20Mintable.sol";
 import "./MinterRoleMock.sol";
 
-
 contract ERC20MintableMock is ERC20Mintable, MinterRoleMock {
-
     constructor() public {
         ERC20Mintable.initialize(msg.sender);
     }

contracts/mocks/ERC20Mock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20.sol";
 
-
 // mock class using ERC20
 contract ERC20Mock is ERC20 {
-
-    constructor(address initialAccount, uint256 initialBalance) public {
+    constructor (address initialAccount, uint256 initialBalance) public {
         _mint(initialAccount, initialBalance);
     }
 
@@ -21,5 +19,4 @@ contract ERC20Mock is ERC20 {
     function burnFrom(address account, uint256 amount) public {
         _burnFrom(account, amount);
     }
-
 }

contracts/mocks/ERC20PausableMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20Pausable.sol";
 import "./PauserRoleMock.sol";
 
-
 // mock class using ERC20Pausable
 contract ERC20PausableMock is ERC20Pausable, PauserRoleMock {
-
-    constructor(address initialAccount, uint initialBalance) public {
+    constructor (address initialAccount, uint initialBalance) public {
         ERC20Pausable.initialize(msg.sender);
-
         _mint(initialAccount, initialBalance);
     }
-
 }

contracts/mocks/ERC20WithMetadataMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20.sol";
 import "../drafts/ERC1046/TokenMetadata.sol";
 
-
 contract ERC20WithMetadataMock is ERC20, ERC20WithMetadata {
-    constructor(string tokenURI) public {
+    constructor (string memory tokenURI) public {
         ERC20WithMetadata.initialize(tokenURI);
     }
 }

contracts/mocks/ERC721FullMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/ERC721Full.sol";
 import "../token/ERC721/ERC721Mintable.sol";
 import "../token/ERC721/ERC721MetadataMintable.sol";
 import "../token/ERC721/ERC721Burnable.sol";
 
-
 /**
  * @title ERC721FullMock
- * This mock just provides a public mint and burn functions for testing purposes,
- * and a public setter for metadata URI
+ * This mock just provides public functions for setting metadata URI, getting all tokens of an owner,
+ * checking token existence, removal of a token from an address
  */
 contract ERC721FullMock is ERC721Full, ERC721Mintable, ERC721MetadataMintable, ERC721Burnable {
-    constructor(string name, string symbol) public
-    {
+    constructor (string memory name, string memory symbol) public {
         ERC721.initialize();
         ERC721Metadata.initialize(name, symbol);
         ERC721Enumerable.initialize();
@@ -25,11 +23,11 @@ contract ERC721FullMock is ERC721Full, ERC721Mintable, ERC721MetadataMintable, E
         return _exists(tokenId);
     }
 
-    function setTokenURI(uint256 tokenId, string uri) public {
-        _setTokenURI(tokenId, uri);
+    function tokensOfOwner(address owner) public view returns (uint256[] memory) {
+        return _tokensOfOwner(owner);
     }
 
-    function removeTokenFrom(address from, uint256 tokenId) public {
-        _removeTokenFrom(from, tokenId);
+    function setTokenURI(uint256 tokenId, string memory uri) public {
+        _setTokenURI(tokenId, uri);
     }
 }

contracts/mocks/ERC721MintableBurnableImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/ERC721Full.sol";
 import "../token/ERC721/ERC721Mintable.sol";
 import "../token/ERC721/ERC721MetadataMintable.sol";
 import "../token/ERC721/ERC721Burnable.sol";
 
-
 /**
  * @title ERC721MintableBurnableImpl
  */
-contract ERC721MintableBurnableImpl
-    is ERC721Full, ERC721Mintable, ERC721MetadataMintable, ERC721Burnable {
-
-    constructor()
-        public
-    {
+contract ERC721MintableBurnableImpl is ERC721Full, ERC721Mintable, ERC721MetadataMintable, ERC721Burnable {
+    constructor () public {
         ERC721.initialize();
         ERC721Metadata.initialize("Test", "TEST");
         ERC721Enumerable.initialize();

contracts/mocks/ERC721Mock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/ERC721.sol";
 
-
 /**
  * @title ERC721Mock
  * This mock just provides a public mint and burn functions for testing purposes
@@ -16,7 +15,11 @@ contract ERC721Mock is ERC721 {
         _mint(to, tokenId);
     }
 
+    function burn(address owner, uint256 tokenId) public {
+        _burn(owner, tokenId);
+    }
+
     function burn(uint256 tokenId) public {
-        _burn(ownerOf(tokenId), tokenId);
+        _burn(tokenId);
     }
 }

contracts/mocks/ERC721PausableMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/ERC721Pausable.sol";
 import "./PauserRoleMock.sol";
 
-
 /**
  * @title ERC721PausableMock
  * This mock just provides a public mint, burn and exists functions for testing purposes
@@ -19,7 +18,7 @@ contract ERC721PausableMock is ERC721Pausable, PauserRoleMock {
     }
 
     function burn(uint256 tokenId) public {
-        super._burn(ownerOf(tokenId), tokenId);
+        super._burn(tokenId);
     }
 
     function exists(uint256 tokenId) public view returns (bool) {

contracts/mocks/ERC721ReceiverMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/IERC721Receiver.sol";
 
-
 contract ERC721ReceiverMock is IERC721Receiver {
     bytes4 private _retval;
     bool private _reverts;
 
-    event Received(
-        address operator,
-        address from,
-        uint256 tokenId,
-        bytes data,
-        uint256 gas
-    );
+    event Received(address operator, address from, uint256 tokenId, bytes data, uint256 gas);
 
-    constructor(bytes4 retval, bool reverts) public {
+    constructor (bytes4 retval, bool reverts) public {
         _retval = retval;
         _reverts = reverts;
     }
 
-    function onERC721Received(
-        address operator,
-        address from,
-        uint256 tokenId,
-        bytes data
-    )
-        public
-        returns(bytes4)
+    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)
+        public returns (bytes4)
     {
         require(!_reverts);
-        emit Received(
-            operator,
-            from,
-            tokenId,
-            data,
-            gasleft() // msg.gas was deprecated in solidityv0.4.21
-        );
+        emit Received(operator, from, tokenId, data, gasleft());
         return _retval;
     }
 }

contracts/mocks/EventEmitter.sol

+pragma solidity ^0.5.0;
+
+contract EventEmitter {
+    event Argumentless();
+    event ShortUint(uint8 value);
+    event ShortInt(int8 value);
+    event LongUint(uint256 value);
+    event LongInt(int256 value);
+    event Address(address value);
+    event Boolean(bool value);
+    event String(string value);
+    event LongUintBooleanString(uint256 uintValue, bool booleanValue, string stringValue);
+
+    constructor (uint8 uintValue, bool booleanValue, string memory stringValue) public {
+        emit ShortUint(uintValue);
+        emit Boolean(booleanValue);
+        emit String(stringValue);
+    }
+
+    function emitArgumentless() public {
+        emit Argumentless();
+    }
+
+    function emitShortUint(uint8 value) public {
+        emit ShortUint(value);
+    }
+
+    function emitShortInt(int8 value) public {
+        emit ShortInt(value);
+    }
+
+    function emitLongUint(uint256 value) public {
+        emit LongUint(value);
+    }
+
+    function emitLongInt(int256 value) public {
+        emit LongInt(value);
+    }
+
+    function emitAddress(address value) public {
+        emit Address(value);
+    }
+
+    function emitBoolean(bool value) public {
+        emit Boolean(value);
+    }
+
+    function emitString(string memory value) public {
+        emit String(value);
+    }
+
+    function emitLongUintBooleanString(uint256 uintValue, bool booleanValue, string memory stringValue) public {
+        emit LongUintBooleanString(uintValue, booleanValue, stringValue);
+    }
+
+    function emitLongUintAndBoolean(uint256 uintValue, bool boolValue) public {
+        emit LongUint(uintValue);
+        emit Boolean(boolValue);
+    }
+
+    function emitStringAndEmitIndirectly(string memory value, IndirectEventEmitter emitter) public {
+        emit String(value);
+        emitter.emitStringIndirectly(value);
+    }
+}
+
+contract IndirectEventEmitter {
+    event IndirectString(string value);
+
+    function emitStringIndirectly(string memory value) public {
+        emit IndirectString(value);
+    }
+}

contracts/mocks/Failer.sol

+pragma solidity ^0.5.0;
+
+contract Failer {
+    uint256[] private array;
+
+    function dontFail() public pure {
+        // solhint-disable-previous-line no-empty-blocks
+    }
+
+    function failWithRevert() public pure {
+        revert();
+    }
+
+    function failWithThrow() public pure {
+        assert(false);
+    }
+
+    function failWithOutOfGas() public {
+        for (uint256 i = 0; i < 2**200; ++i) {
+            array.push(i);
+        }
+    }
+}

contracts/mocks/FinalizableCrowdsaleImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/distribution/FinalizableCrowdsale.sol";
 
-
 contract FinalizableCrowdsaleImpl is FinalizableCrowdsale {
-
-    constructor (
-        uint256 openingTime,
-        uint256 closingTime,
-        uint256 rate,
-        address wallet,
-        IERC20 token
-    )
+    constructor (uint256 openingTime, uint256 closingTime, uint256 rate, address payable wallet, IERC20 token)
         public
     {
         Crowdsale.initialize(rate, wallet, token);
         TimedCrowdsale.initialize(openingTime, closingTime);
     }
-
 }

contracts/mocks/IncreasingPriceCrowdsaleImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../crowdsale/price/IncreasingPriceCrowdsale.sol";
 import "../math/SafeMath.sol";
 
-
 contract IncreasingPriceCrowdsaleImpl is IncreasingPriceCrowdsale {
-
     constructor (
         uint256 openingTime,
         uint256 closingTime,
-        address wallet,
+        address payable wallet,
         IERC20 token,
         uint256 initialRate,
         uint256 finalRate
@@ -20,5 +18,4 @@ contract IncreasingPriceCrowdsaleImpl is IncreasingPriceCrowdsale {
         TimedCrowdsale.initialize(openingTime, closingTime);
         IncreasingPriceCrowdsale.initialize(initialRate, finalRate);
     }
-
 }

contracts/mocks/IndividuallyCappedCrowdsaleImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/validation/IndividuallyCappedCrowdsale.sol";
 import "./CapperRoleMock.sol";
 
-
-contract IndividuallyCappedCrowdsaleImpl
-    is Crowdsale, IndividuallyCappedCrowdsale, CapperRoleMock {
-
-    constructor(
-        uint256 rate,
-        address wallet,
-        IERC20 token
-    )
-        public
-    {
+contract IndividuallyCappedCrowdsaleImpl is IndividuallyCappedCrowdsale, CapperRoleMock {
+    constructor (uint256 rate, address payable wallet, IERC20 token) public {
         Crowdsale.initialize(rate, wallet, token);
         IndividuallyCappedCrowdsale.initialize(msg.sender);
     }

contracts/mocks/MathMock.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 import "../math/Math.sol";
 
-
 contract MathMock {
     function max(uint256 a, uint256 b) public pure returns (uint256) {
         return Math.max(a, b);

contracts/mocks/MerkleProofWrapper.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import { MerkleProof } from "../cryptography/MerkleProof.sol";
 
-
 contract MerkleProofWrapper {
-
-    function verify(
-        bytes32[] proof,
-        bytes32 root,
-        bytes32 leaf
-    )
-        public
-        pure
-        returns (bool)
-    {
+    function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) public pure returns (bool) {
         return MerkleProof.verify(proof, root, leaf);
     }
 }

contracts/mocks/MintedCrowdsaleImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20Mintable.sol";
 import "../crowdsale/emission/MintedCrowdsale.sol";
 
-
 contract MintedCrowdsaleImpl is MintedCrowdsale {
-
-    constructor (
-        uint256 rate,
-        address wallet,
-        ERC20Mintable token
-    )
-        public
-    {
+    constructor (uint256 rate, address payable wallet, ERC20Mintable token) public {
         Crowdsale.initialize(rate, wallet, token);
     }
-
 }

contracts/mocks/MinterRoleMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/roles/MinterRole.sol";
 
-
 contract MinterRoleMock is MinterRole {
     constructor() public {
         MinterRole.initialize(msg.sender);
@@ -13,6 +12,7 @@ contract MinterRoleMock is MinterRole {
     }
 
     function onlyMinterMock() public view onlyMinter {
+        // solhint-disable-previous-line no-empty-blocks
     }
 
     // Causes a compilation error if super._removeMinter is not internal

contracts/mocks/OwnableInterfaceId.sol

+pragma solidity ^0.5.0;
+
+import "../ownership/Ownable.sol";
+
+/**
+ * @title Ownable interface id calculator.
+ * @dev See the EIP165 specification for more information:
+ * https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md#specification
+ */
+contract OwnableInterfaceId {
+    function getInterfaceId() public pure returns (bytes4) {
+        Ownable i;
+        return i.owner.selector ^ i.isOwner.selector ^ i.renounceOwnership.selector ^ i.transferOwnership.selector;
+    }
+}

contracts/mocks/OwnableMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
-import { Ownable } from "../ownership/Ownable.sol";
+import "../ownership/Ownable.sol";
 
 contract OwnableMock is Ownable {
     constructor() {

contracts/mocks/PausableCrowdsaleImpl.sol

+pragma solidity ^0.5.0;
+
+import "../token/ERC20/ERC20.sol";
+import "../crowdsale/validation/PausableCrowdsale.sol";
+
+contract PausableCrowdsaleImpl is PausableCrowdsale {
+    constructor (uint256 _rate, address payable _wallet, ERC20 _token) public Crowdsale(_rate, _wallet, _token) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
+}

contracts/mocks/PausableMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../lifecycle/Pausable.sol";
 import "./PauserRoleMock.sol";
 
-
 // mock class using Pausable
 contract PausableMock is Pausable, PauserRoleMock {
     bool public drasticMeasureTaken;
     uint256 public count;
 
-    constructor() public {
+    constructor () public {
         Pausable.initialize(msg.sender);
 
         drasticMeasureTaken = false;
@@ -23,5 +22,4 @@ contract PausableMock is Pausable, PauserRoleMock {
     function drasticMeasure() external whenPaused {
         drasticMeasureTaken = true;
     }
-
 }

contracts/mocks/PauserRoleMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/roles/PauserRole.sol";
 
-
 contract PauserRoleMock is PauserRole {
-    constructor() public {
+    constructor () public {
         PauserRole.initialize(msg.sender);
     }
 
@@ -13,6 +12,7 @@ contract PauserRoleMock is PauserRole {
     }
 
     function onlyPauserMock() public view onlyPauser {
+        // solhint-disable-previous-line no-empty-blocks
     }
 
     // Causes a compilation error if super._removePauser is not internal

contracts/mocks/SplitPaymentMock.sol → contracts/mocks/PaymentSplitterMock.sol

 pragma solidity ^0.4.24;
 
-import "../payment/SplitPayment.sol";
+import "../payment/PaymentSplitter.sol";
 
-contract SplitPaymentMock is SplitPayment {
+contract PaymentSplitterMock is PaymentSplitter {
     constructor(address[] payees, uint256[] shares) public {
-        SplitPayment.initialize(payees, shares);
+        PaymentSplitter.initialize(payees, shares);
     }
 }

contracts/mocks/PostDeliveryCrowdsaleImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/distribution/PostDeliveryCrowdsale.sol";
 
-
 contract PostDeliveryCrowdsaleImpl is PostDeliveryCrowdsale {
-
-    constructor (
-        uint256 openingTime,
-        uint256 closingTime,
-        uint256 rate,
-        address wallet,
-        IERC20 token
-    )
+    constructor (uint256 openingTime, uint256 closingTime, uint256 rate, address payable wallet, IERC20 token)
         public
+        TimedCrowdsale(openingTime, closingTime)
+        Crowdsale(rate, wallet, token)
     {
         Crowdsale.initialize(rate, wallet, token);
         TimedCrowdsale.initialize(openingTime, closingTime);
     }
-
 }

contracts/mocks/PullPaymentMock.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 import "../payment/PullPayment.sol";
 
-
 // mock class using PullPayment
 contract PullPaymentMock is PullPayment {
-
-    constructor() public payable {
+    constructor () public payable {
         PullPayment.initialize();
     }
 
@@ -15,5 +12,4 @@ contract PullPaymentMock is PullPayment {
     function callTransfer(address dest, uint256 amount) public {
         _asyncTransfer(dest, amount);
     }
-
 }

contracts/mocks/ReentrancyAttack.sol

-pragma solidity ^0.4.24;
-
+pragma solidity ^0.5.0;
 
 contract ReentrancyAttack {
-
     function callSender(bytes4 data) public {
-        // solium-disable-next-line security/no-low-level-calls
-        require(msg.sender.call(abi.encodeWithSelector(data)));
+        // solhint-disable-next-line avoid-low-level-calls
+        (bool success,) = msg.sender.call(abi.encodeWithSelector(data));
+        require(success);
     }
-
 }

contracts/mocks/ReentrancyMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../utils/ReentrancyGuard.sol";
 import "./ReentrancyAttack.sol";
 
-
 contract ReentrancyMock is ReentrancyGuard {
-
     uint256 public counter;
 
-    constructor() public {
+    constructor () public {
         ReentrancyGuard.initialize();
         counter = 0;
     }
@@ -27,9 +25,9 @@ contract ReentrancyMock is ReentrancyGuard {
     function countThisRecursive(uint256 n) public nonReentrant {
         if (n > 0) {
             count();
-            // solium-disable-next-line security/no-low-level-calls
-            bool result = address(this).call(abi.encodeWithSignature("countThisRecursive(uint256)", n - 1));
-            require(result == true);
+            // solhint-disable-next-line avoid-low-level-calls
+            (bool success,) = address(this).call(abi.encodeWithSignature("countThisRecursive(uint256)", n - 1));
+            require(success);
         }
     }
 
@@ -42,5 +40,4 @@ contract ReentrancyMock is ReentrancyGuard {
     function count() private {
         counter += 1;
     }
-
 }

contracts/mocks/RefundableCrowdsaleImpl.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
-import "../token/ERC20/ERC20Mintable.sol";
+import "../token/ERC20/IERC20.sol";
 import "../crowdsale/distribution/RefundableCrowdsale.sol";
 
-
 contract RefundableCrowdsaleImpl is Crowdsale, TimedCrowdsale, RefundableCrowdsale {
-
     constructor (
         uint256 openingTime,
         uint256 closingTime,
         uint256 rate,
-        address wallet,
-        ERC20Mintable token,
+        address payable wallet,
+        IERC20 token,
         uint256 goal
     )
         public
@@ -20,5 +18,4 @@ contract RefundableCrowdsaleImpl is Crowdsale, TimedCrowdsale, RefundableCrowdsa
         TimedCrowdsale.initialize(openingTime, closingTime);
         RefundableCrowdsale.initialize(goal);
     }
-
 }

contracts/mocks/RefundablePostDeliveryCrowdsaleImpl.sol

+pragma solidity ^0.5.0;
+
+import "../token/ERC20/IERC20.sol";
+import "../crowdsale/distribution/RefundablePostDeliveryCrowdsale.sol";
+
+contract RefundablePostDeliveryCrowdsaleImpl is RefundablePostDeliveryCrowdsale {
+    constructor (
+        uint256 openingTime,
+        uint256 closingTime,
+        uint256 rate,
+        address payable wallet,
+        IERC20 token,
+        uint256 goal
+    )
+        public
+        Crowdsale(rate, wallet, token)
+        TimedCrowdsale(openingTime, closingTime)
+        RefundableCrowdsale(goal)
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
+}

contracts/mocks/RolesMock.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/Roles.sol";
 
-
 contract RolesMock {
     using Roles for Roles.Role;
 

contracts/mocks/SafeERC20Helper.sol

-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../token/ERC20/SafeERC20.sol";
 
-
-contract ERC20FailingMock is IERC20 {
-    function totalSupply() public view returns (uint256) {
-        return 0;
-    }
+contract ERC20FailingMock {
+    uint256 private _allowance;
 
     function transfer(address, uint256) public returns (bool) {
         return false;
@@ -21,20 +18,13 @@ contract ERC20FailingMock is IERC20 {
         return false;
     }
 
-    function balanceOf(address) public view returns (uint256) {
-        return 0;
-    }
-
     function allowance(address, address) public view returns (uint256) {
         return 0;
     }
 }
 
-
-contract ERC20SucceedingMock is IERC20 {
-    function totalSupply() public view returns (uint256) {
-        return 0;
-    }
+contract ERC20SucceedingMock {
+    uint256 private _allowance;
 
     function transfer(address, uint256) public returns (bool) {
         return true;
@@ -48,25 +38,24 @@ contract ERC20SucceedingMock is IERC20 {
         return true;
     }
 
-    function balanceOf(address) public view returns (uint256) {
-        return 0;
+    function setAllowance(uint256 allowance_) public {
+        _allowance = allowance_;
     }
 
     function allowance(address, address) public view returns (uint256) {
-        return 0;
+        return _allowance;
     }
 }
 
-
 contract SafeERC20Helper {
     using SafeERC20 for IERC20;
 
     IERC20 private _failing;
     IERC20 private _succeeding;
 
-    constructor() public {
-        _failing = new ERC20FailingMock();
-        _succeeding = new ERC20SucceedingMock();
+    constructor () public {
+        _failing = IERC20(address(new ERC20FailingMock()));
+        _succeeding = IERC20(address(new ERC20SucceedingMock()));
     }
 
     function doFailingTransfer() public {
@@ -81,6 +70,14 @@ contract SafeERC20Helper {
         _failing.safeApprove(address(0), 0);
     }
 
+    function doFailingIncreaseAllowance() public {
+        _failing.safeIncreaseAllowance(address(0), 0);
+    }
+
+    function doFailingDecreaseAllowance() public {
+        _failing.safeDecreaseAllowance(address(0), 0);
+    }
+
     function doSucceedingTransfer() public {
         _succeeding.safeTransfer(address(0), 0);
     }
@@ -89,7 +86,23 @@ contract SafeERC20Helper {
         _succeeding.safeTransferFrom(address(0), address(0), 0);
     }
 
-    function doSucceedingApprove() public {
-        _succeeding.safeApprove(address(0), 0);
+    function doSucceedingApprove(uint256 amount) public {
+        _succeeding.safeApprove(address(0), amount);
+    }
+
+    function doSucceedingIncreaseAllowance(uint256 amount) public {
+        _succeeding.safeIncreaseAllowance(address(0), amount);
+    }
+
+    function doSucceedingDecreaseAllowance(uint256 amount) public {
+        _succeeding.safeDecreaseAllowance(address(0), amount);
+    }
+
+    function setAllowance(uint256 allowance_) public {
+        ERC20SucceedingMock(address(_succeeding)).setAllowance(allowance_);
+    }
+
+    function allowance() public view returns (uint256) {
+        return _succeeding.allowance(address(0), address(0));
     }
 }