feat: Improve readability of fork configuration. Support FORK_BLOCK_NUMBER enviroment variable.

Author: kartojal

hardhat.config.ts

@@ -5,7 +5,12 @@ import { HardhatUserConfig } from 'hardhat/types';
 import { accounts } from './test-wallets.js';
 import { eEthereumNetwork, eNetwork, ePolygonNetwork, eXDaiNetwork } from './helpers/types';
 import { BUIDLEREVM_CHAINID, COVERAGE_CHAINID } from './helpers/buidler-constants';
-import { NETWORKS_RPC_URL, NETWORKS_DEFAULT_GAS, BLOCK_TO_FORK } from './helper-hardhat-config';
+import {
+  NETWORKS_RPC_URL,
+  NETWORKS_DEFAULT_GAS,
+  BLOCK_TO_FORK,
+  buildForkConfig,
+} from './helper-hardhat-config';
 
 require('dotenv').config();
 
@@ -16,6 +21,7 @@ import 'hardhat-gas-reporter';
 import 'hardhat-typechain';
 import '@tenderly/hardhat-tenderly';
 import 'solidity-coverage';
+import { fork } from 'child_process';
 
 const SKIP_LOAD = process.env.SKIP_LOAD === 'true';
 const DEFAULT_BLOCK_GAS_LIMIT = 12450000;
@@ -24,7 +30,6 @@ const HARDFORK = 'istanbul';
 const ETHERSCAN_KEY = process.env.ETHERSCAN_KEY || '';
 const MNEMONIC_PATH = "m/44'/60'/0'/0";
 const MNEMONIC = process.env.MNEMONIC || '';
-const FORK = process.env.FORK || '';
 
 // Prevent to load scripts before compilation and typechain
 if (!SKIP_LOAD) {
@@ -57,15 +62,7 @@ const getCommonNetworkConfig = (networkName: eNetwork, networkId: number) => ({
   },
 });
 
-const forkMode = FORK
-  ? {
-      url: NETWORKS_RPC_URL[FORK],
-      ...(FORK &&
-        BLOCK_TO_FORK[FORK] && {
-          blockNumber: BLOCK_TO_FORK[FORK],
-        }),
-    }
-  : undefined;
+let forkMode;
 
 const buidlerConfig: HardhatUserConfig = {
   solidity: {
@@ -114,7 +111,7 @@ const buidlerConfig: HardhatUserConfig = {
         privateKey: secretKey,
         balance,
       })),
-      forking: forkMode,
+      forking: buildForkConfig(),
     },
     buidlerevm_docker: {
       hardfork: 'berlin',

helper-hardhat-config.ts

@@ -1,4 +1,5 @@
 // @ts-ignore
+import { HardhatNetworkForkingUserConfig, HardhatUserConfig } from 'hardhat/types';
 import {
   eEthereumNetwork,
   ePolygonNetwork,
@@ -11,9 +12,26 @@ require('dotenv').config();
 const INFURA_KEY = process.env.INFURA_KEY || '';
 const ALCHEMY_KEY = process.env.ALCHEMY_KEY || '';
 const TENDERLY_FORK_ID = process.env.TENDERLY_FORK_ID || '';
+const FORK = process.env.FORK || '';
+const FORK_BLOCK_NUMBER = process.env.FORK_BLOCK_NUMBER
+  ? parseInt(process.env.FORK_BLOCK_NUMBER)
+  : 0;
 
 const GWEI = 1000 * 1000 * 1000;
 
+export const buildForkConfig = (): HardhatNetworkForkingUserConfig | undefined => {
+  let forkMode;
+  if (FORK) {
+    forkMode = {
+      url: NETWORKS_RPC_URL[FORK],
+    };
+    if (FORK_BLOCK_NUMBER || BLOCK_TO_FORK[FORK]) {
+      forkMode.blockNumber = FORK_BLOCK_NUMBER || BLOCK_TO_FORK[FORK];
+    }
+  }
+  return forkMode;
+};
+
 export const NETWORKS_RPC_URL: iParamsPerNetwork<string> = {
   [eEthereumNetwork.kovan]: ALCHEMY_KEY
     ? `https://eth-kovan.alchemyapi.io/v2/${ALCHEMY_KEY}`

package.json

@@ -23,7 +23,7 @@
     "test-amm-scenarios": "npm run compile && TS_NODE_TRANSPILE_ONLY=1 hardhat test ./test-suites/test-amm/__setup.spec.ts test-suites/test-amm/scenario.spec.ts",
     "test-scenarios": "npm run compile && npx hardhat test test-suites/test-aave/__setup.spec.ts test-suites/test-aave/scenario.spec.ts",
     "test-subgraph:scenarios": "npm run compile && hardhat --network hardhatevm_docker test test-suites/test-aave/__setup.spec.ts test-suites/test-aave/subgraph-scenarios.spec.ts",
-    "test:main:check-list": "npm run compile && FORK=true TS_NODE_TRANSPILE_ONLY=1 hardhat test  test-suites/test-aave/__setup.spec.ts test-suites/test-aave/mainnet/check-list.spec.ts",
+    "test:main:check-list": "npm run compile && FORK=main TS_NODE_TRANSPILE_ONLY=1 hardhat test  test-suites/test-aave/__setup.spec.ts test-suites/test-aave/mainnet/check-list.spec.ts",
     "dev:coverage": "buidler compile --force && buidler coverage --network coverage",
     "aave:evm:dev:migration": "npm run compile && hardhat aave:dev",
     "aave:docker:full:migration": "npm run compile && npm run hardhat:docker -- aave:mainnet --skip-registry",