Optimism L2 - token [Hardhat - v2]

.github/workflows/changelog.yml

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+#
+# This action checks PRs to see if any CHANGELOG* files were updated.
+# If none were, it will add a message to the PR asking if it would make sense to do so.
+#
+name: Changelog
+
+on: pull_request
+
+jobs:
+  changelog:
+    name: Changelog checker
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check for changed files
+        id: changedfiles
+        uses: futuratrepadeira/changed-files@186b5b30b1f5e44ed655a59652746c3ce00d53ef # Version v3.1.1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          pattern: '^CHANGELOG.*$'
+      - name: Make a comment
+        uses: unsplash/comment-on-pr@d1a1d5dd1eb1bb657a01f4d92dd5e4d5bb7857d3 # Version v1.2.0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        if: contains(steps.changedfiles.outputs.files_updated, 'CHANGELOG') != true && contains(steps.changedfiles.outputs.files_created, 'CHANGELOG') != true
+        with:
+          msg: "I see that you haven't updated any CHANGELOG files. Would it make sense to do so?"
+          check_for_duplicate_msg: false

.github/workflows/main.yml

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+name: Main
+
+on:
+  push:
+    branches:
+      - master
+  pull_request: ~
+
+jobs:
+  run-basic-checks:
+    name: Run linters and unit tests
+    runs-on: [self-hosted]
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: '14.x'
+      - run: npm install -g yarn
+      - run: yarn install
+      - run: yarn setup
+      - run: yarn lint
+      - run: yarn test
+  run-integration:
+    name: Setup and run integration tests
+    needs: [run-basic-checks]
+    runs-on: [self-hosted]
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: '14.x'
+      - run: npm install -g yarn
+      - run: yarn install
+      - run: yarn setup
+      - name: Setup Optimism L2 local network
+        run: yarn script:oe:up
+      - run: yarn test --network optimism

.gitignore

@@ -8,3 +8,6 @@ coverage.json
 
 # Misc
 .DS_STORE
+
+# Optimism monorepo used for integration tests
+/optimism

.tool-versions

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+node 14.16.0
+yarn 1.22.4

CHANGELOG.md

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+# Changelog LinkToken
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased] - Apr 2021
+
+### Added
+
+- Access controlled mintable & burnable LinkToken, for use on sidechains and L2 networks.
+
+### Changed
+
+- Migrated to Hardhat and Waffle
+
+### Fixed
+
+### Removed
+
+- Truffle framework and tests dependencies
+
+## [1.1.0] - Mar 2021
+
+Initial @chainlink/token release!
+
+### Added
+
+- Solidity 0.6 support
+- Simple token swapping contract
+
+## [1.0.6] - Sep 2018
+
+Initial link_token release!

README.md

@@ -1,41 +1,73 @@
-# LINK Token Contracts [![Build Status](https://travis-ci.org/smartcontractkit/LinkToken.svg?branch=master)](https://travis-ci.org/smartcontractkit/LinkToken)
+# LINK Token Contracts
 
 The LINK token is an [EIP20](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md) token with additional [ERC677](https://github.com/ethereum/EIPs/issues/677) functionality.
 
 The total supply of the token is 1,000,000,000, and each token is divisible up to 18 decimal places.
 
 To prevent accidental burns, the token does not allow transfers to the contract itself and to 0x0.
 
-Security audit for [v0.4 version of the contracts](./contracts/v0.4/) is available [here](https://gist.github.com/Arachnid/4aa88041bd6e34835b8c0fd051245e79).
+Security audit for [0.4 version of the contracts](./contracts/v0.4/) is available [here](https://gist.github.com/Arachnid/4aa88041bd6e34835b8c0fd051245e79).
 
 ## Details
 
 - Deployments:
-  - Ethereum Mainnet [LinkToken v0.4](./flat/v0.4/LinkToken.sol): [0x514910771AF9Ca656af840dff83E8264EcF986CA](https://etherscan.io/address/0x514910771af9ca656af840dff83e8264ecf986ca)
+  - Ethereum Mainnet [LinkToken 0.4](./flat/v0.4/LinkToken.sol): [0x514910771AF9Ca656af840dff83E8264EcF986CA](https://etherscan.io/address/0x514910771af9ca656af840dff83e8264ecf986ca)
 - Decimals: 18
 - Name: ChainLink Token
 - Symbol: LINK
 
-## Installation
+## Setup
 
-The project contains [v0.4 contracts](./contracts/v0.4/) that were used for LINK Ethereum Mainnet deployment in 2017. For deployments moving forward, we use the updated [v0.6 contracts](./contracts/v0.6/) which use a more recent version of solc and the OpenZeppelin token standards. These updates include a minor ABI change around approval/allowance naming.
+The project contains [0.4 contracts](./contracts/v0.4/) that were used for LINK Ethereum Mainnet deployment in 2017. For deployments moving forward, we use the updated [0.6 contracts](./contracts/v0.6/) which use a more recent version of solc and the OpenZeppelin token standards. These updates include a minor ABI change around approval/allowance naming.
 
 ```bash
 yarn install
 ```
 
-## Testing
-
 Setup contracts:
 
 ```bash
 yarn setup
 ```
 
+This will compile all versions of the contracts.
+
+## Testing
+
 Run tests:
 
 ```bash
 yarn test
 ```
 
-This will test both v0.4 and v0.6 versions of the contracts.
+This will run unit tests for all versions of the contracts.
+
+## Integration testing
+
+Integration tests are currently setup for Optimism contracts, and to run them make sure you have a local network running first.
+
+The network can be started using a helpful script, which will clone the [Optimism monorepo](https://github.com/ethereum-optimism/optimism), build the :
+
+```bash
+yarn script:oe:up
+```
+
+Run tests:
+
+```bash
+yarn test --network optimism
+```
+
+This will run unit tests for all versions of the contracts, plus supported integration tests against the local L1 & L2 networks.
+
+The network can be stopped using another script:
+
+```bash
+yarn script:oe:down
+```
+
+Or use the clean script, which will also delete all the images:
+
+```bash
+yarn script:oe:clean
+```

contracts/v0.7/README.md

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+# LINK Token Contracts v0.7
+
+## Token bridge contracts
+
+LinkToken bridge contracts can be found in the [./bridge](./bridge) directory.

contracts/v0.7/bridge/README.md

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+# LINK Token Bridge v0.7
+
+- `./LinkTokenChild.sol`: A mintable & burnable child LinkToken contract to be used on child networks.

contracts/v0.7/bridge/token/IERC20Child.sol

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+// SPDX-License-Identifier: MIT
+pragma solidity >0.6.0 <0.8.0;
+
+/* Interface Imports */
+import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
+/// @dev Interface of the child ERC20 token, for use on sidechains and L2 networks.
+interface IERC20Child is IERC20 {
+  /**
+   * @notice called by bridge gateway when tokens are deposited on root chain
+   * Should handle deposits by minting the required amount for the recipient
+   *
+   * @param recipient an address for whom deposit is being done
+   * @param amount total amount to deposit/mint
+   */
+  function deposit(address recipient, uint256 amount) external;
+
+  /**
+   * @notice called by bridge gateway when tokens are withdrawn back to root chain
+   * @dev Should burn recipient's tokens.
+   *
+   * @param amount total amount to withdraw/burn
+   */
+  function withdraw(uint256 amount) external;
+}

contracts/v0.7/bridge/token/LinkTokenChild.sol

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+// SPDX-License-Identifier: MIT
+pragma solidity >0.6.0 <0.8.0;
+
+/* Interface Imports */
+import { IERC20Child } from "./IERC20Child.sol";
+
+/* Contract Imports */
+import { AccessControl } from "@openzeppelin/contracts/access/AccessControl.sol";
+import { LinkToken } from "../../../v0.6/LinkToken.sol";
+
+/// @dev Access controlled mintable & burnable LinkToken, for use on sidechains and L2 networks.
+contract LinkTokenChild is IERC20Child, AccessControl, LinkToken {
+
+  // Using this role the bridge gateway can deposit/withdraw (mint/burn)
+  bytes32 public constant BRIDGE_GATEWAY_ROLE = keccak256("BRIDGE_GATEWAY_ROLE");
+
+  /**
+   * @dev Overrides parent contract so no tokens are minted on deployment.
+   * @inheritdoc LinkToken
+   */
+  function _onCreate()
+    internal
+    override
+  {
+    _setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
+  }
+
+  /**
+   * @dev Modifier to check access by role.
+   *
+   * @param role the required role
+   */
+  modifier onlyRole(
+    bytes32 role
+  ) {
+    require(hasRole(role, _msgSender()), "LinkTokenChild: missing role");
+    _;
+  }
+
+  /**
+   * @dev Only callable by account with BRIDGE_GATEWAY_ROLE
+   * @inheritdoc IERC20Child
+   */
+  function deposit(
+    address recipient,
+    uint256 amount
+  )
+    external
+    override
+    virtual
+    onlyRole(BRIDGE_GATEWAY_ROLE)
+  {
+    _mint(recipient, amount);
+  }
+
+  /**
+   * @dev Only callable by account with BRIDGE_GATEWAY_ROLE
+   * @inheritdoc IERC20Child
+   */
+  function withdraw(
+    uint256 amount
+  )
+    external
+    override
+    virtual
+    onlyRole(BRIDGE_GATEWAY_ROLE)
+  {
+    _burn(_msgSender(), amount);
+  }
+}

env/.env.kovan

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+### KOVAN
+# make sure this private key has Kovan ETH!
+PRIVATE_KEY=
+L1_WEB3_URL=https://kovan.infura.io/v3/API_KEY
+L2_WEB3_URL=https://kovan.optimism.io

env/.env.local

@@ -0,0 +1,4 @@
+### LOCAL (optimism-integration repo)
+PRIVATE_KEY=0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80
+L1_WEB3_URL=http://127.0.0.1:9545
+L2_WEB3_URL=http://127.0.0.1:8545