Adding a contract to store minimum required client version

packages/protocol/contracts/governance/BlockchainParams.sol

@@ -0,0 +1,34 @@
+pragma solidity ^0.5.3;
+
+import "openzeppelin-solidity/contracts/ownership/Ownable.sol";
+import "../common/Initializable.sol";
+
+/**
+ * @title Contract for storing blockchain parameters that can be set by governance.
+ */
+contract BlockchainParams is Ownable, Initializable {
+
+  string public minimumClientVersion;
+
+  event MinimumClientVersionSet(string minimumClientVersion);
+
+  /**
+   * @notice Initializes critical variables.
+   * @param _minimumClientVersion Minimum client version that can be used in the chain.
+   */
+  function initialize(string calldata _minimumClientVersion) external initializer {
+    _transferOwnership(msg.sender);
+    setMinimumClientVersion(_minimumClientVersion);
+  }
+
+  /**
+   * @notice Sets the minimum client version.
+   * @param _minimumClientVersion Minimum client version that can be used in the chain.
+   */
+  function setMinimumClientVersion(string memory _minimumClientVersion) public onlyOwner {
+    require(bytes(_minimumClientVersion).length > 0, "Minimum client version cannot be empty string");
+    minimumClientVersion = _minimumClientVersion;
+    emit MinimumClientVersionSet(_minimumClientVersion);
+  }
+
+}

packages/protocol/contracts/governance/proxies/BlockchainParamsProxy.sol

@@ -0,0 +1,7 @@
+pragma solidity ^0.5.3;
+
+import "../../common/Proxy.sol";
+
+/* solhint-disable no-empty-blocks */
+contract BlockchainParamsProxy is Proxy {
+}

packages/protocol/lib/proxy-utils.ts

@@ -2,13 +2,14 @@ import Web3 = require('web3')
 
 import { ProxyInstance } from 'types'
 
-export function setAndInitializeImplementation(
+export async function setAndInitializeImplementation(
   web3: Web3,
   proxy: ProxyInstance,
   implementationAddress: string,
   initializerAbi: any,
   ...args: any[]
 ) {
   const callData = web3.eth.abi.encodeFunctionCall(initializerAbi, args)
-  return proxy._setAndInitializeImplementation(implementationAddress, callData as any)
+  const res = await proxy._setAndInitializeImplementation(implementationAddress, callData as any)
+  return res
 }

packages/protocol/lib/registry-utils.ts

@@ -12,6 +12,7 @@ export enum CeloContractName {
   SortedOracles = 'SortedOracles',
   StableToken = 'StableToken',
   Validators = 'Validators',
+  BlockchainParams = 'BlockchainParams',
 }
 
 // TODO(amy): Pull this list from the build artifacts instead
@@ -33,4 +34,5 @@ export const hasEntryInRegistry: string[] = [
   CeloContractName.StableToken,
   CeloContractName.Random,
   CeloContractName.Reserve,
+  CeloContractName.BlockchainParams,
 ]

packages/protocol/migrations/15_blockchainparams.ts

@@ -0,0 +1,15 @@
+import { CeloContractName } from '@celo/protocol/lib/registry-utils'
+import { deploymentForCoreContract } from '@celo/protocol/lib/web3-utils'
+import { BlockchainParamsInstance } from 'types'
+import { config } from '@celo/protocol/migrationsConfig'
+
+const initializeArgs = async (_: string): Promise<any[]> => {
+  return [config.blockchainParams.minimumClientVersion]
+}
+
+module.exports = deploymentForCoreContract<BlockchainParamsInstance>(
+  web3,
+  artifacts,
+  CeloContractName.BlockchainParams,
+  initializeArgs
+)

packages/protocol/migrationsConfig.js

@@ -67,6 +67,9 @@ const DefaultConfig = {
     groupName: 'C-Labs',
     groupUrl: 'https://www.celo.org',
   },
+  blockchainParams: {
+    minimumClientVersion: '1.8.23',
+  },
 }
 
 const linkedLibraries = {

packages/protocol/test/common/linkedlist.ts

@@ -1,13 +1,8 @@
 import { assertRevert } from '@celo/protocol/lib/test-utils'
-// import BigNumber from 'bignumber.js'
 import { LinkedListTestContract, LinkedListTestInstance } from 'types'
 
 const LinkedListTest: LinkedListTestContract = artifacts.require('LinkedListTest')
 
-// @ts-ignore
-// TODO(mcortesi): Use BN
-LinkedListTest.numberFormat = 'BigNumber'
-
 contract('LinkedListTest', () => {
   let linkedListTest: LinkedListTestInstance
 

packages/protocol/test/governance/blockchainparams.ts

@@ -0,0 +1,19 @@
+import { BlockchainParamsContract, BlockchainParamsInstance } from 'types'
+
+const BlockchainParamsTest: BlockchainParamsContract = artifacts.require('BlockchainParams')
+
+contract('BlockchainParams', () => {
+  let blockchainParamsTest: BlockchainParamsInstance
+  const version = '1.8.4'
+
+  beforeEach(async () => {
+    blockchainParamsTest = await BlockchainParamsTest.new()
+  })
+
+  describe('#setMinimumClientVersion()', () => {
+    it('should set the variable', async () => {
+      await blockchainParamsTest.setMinimumClientVersion(version)
+      assert.equal(version, await blockchainParamsTest.minimumClientVersion())
+    })
+  })
+})