Add optional gas reporting to unit test run (#626)

* Add hardhat-gas-reporter package and base config

* Generate an output file from gas reporter when run in CI
Selectively enable gas reporter based on ENABLE_GAS_REPORT env var

* Add gas reports to integration tests

.github/workflows/integration.yml

@@ -42,3 +42,8 @@ jobs:
             yarn build:contracts
             yarn build:contracts:ovm
             yarn test:integration
+        env:
+          FORCE_COLOR: 1
+          ENABLE_GAS_REPORT: 1
+      - name: Print gas report
+        run: cat integration-tests/gas-report.txt

.github/workflows/ts-packages.yml

@@ -54,7 +54,11 @@ jobs:
 
       - name: Test
         run: yarn test:ci
-
+        env:
+          FORCE_COLOR: 1
+          ENABLE_GAS_REPORT: 1
+      - name: Print gas report
+        run: cat packages/contracts/gas-report.txt
   lint:
     name: Linting
     runs-on: ubuntu-latest

integration-tests/hardhat.config.ts

@@ -3,6 +3,9 @@ import { HardhatUserConfig } from 'hardhat/types'
 // Hardhat plugins
 import '@nomiclabs/hardhat-ethers'
 import '@eth-optimism/hardhat-ovm'
+import 'hardhat-gas-reporter'
+
+const enableGasReport = !!process.env.ENABLE_GAS_REPORT
 
 const config: HardhatUserConfig = {
   mocha: {
@@ -18,6 +21,12 @@ const config: HardhatUserConfig = {
   ovm: {
     solcVersion: '0.7.6',
   },
+  gasReporter: {
+    enabled: enableGasReport,
+    currency: 'USD',
+    gasPrice: 100,
+    outputFile: process.env.CI ? 'gas-report.txt' : undefined,
+  },
 }
 
 export default config

integration-tests/package.json

@@ -26,6 +26,7 @@
     "ethereum-waffle": "^3.3.0",
     "ethers": "^5.0.32",
     "hardhat": "^2.1.2",
+    "hardhat-gas-reporter": "^1.0.4",
     "mocha": "^8.3.1",
     "rimraf": "^3.0.2"
   }

packages/contracts/hardhat.config.ts

@@ -14,10 +14,13 @@ import 'hardhat-deploy'
 import '@typechain/hardhat'
 import '@eth-optimism/hardhat-ovm'
 import './tasks/deploy'
+import 'hardhat-gas-reporter'
 
 // Load environment variables from .env
 dotenv.config()
 
+const enableGasReport = !!process.env.ENABLE_GAS_REPORT
+
 const config: HardhatUserConfig = {
   networks: {
     hardhat: {
@@ -64,6 +67,12 @@ const config: HardhatUserConfig = {
       default: 0,
     },
   },
+  gasReporter: {
+    enabled: enableGasReport,
+    currency: 'USD',
+    gasPrice: 100,
+    outputFile: process.env.CI ? 'gas-report.txt' : undefined,
+  },
 }
 
 if (

packages/contracts/package.json

@@ -69,6 +69,7 @@
     "ethers": "^5.0.31",
     "hardhat": "^2.0.8",
     "hardhat-deploy": "^0.7.4",
+    "hardhat-gas-reporter": "^1.0.4",
     "lodash": "^4.17.20",
     "merkle-patricia-tree": "^4.0.0",
     "merkletreejs": "^0.2.12",