From 9a73464d04b3bf9ff28039079c5478bf408a52ef Mon Sep 17 00:00:00 2001
From: CJ42 <cavallerajean@gmail.com>
Date: Tue, 26 Sep 2023 16:37:57 +0100
Subject: [PATCH] ci: update gas benchmark CI with new diff flow

---
 .github/workflows/benchmark.yml | 41 +++++++++++++++++++++++++++++----
 1 file changed, 37 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/benchmark.yml b/.github/workflows/benchmark.yml
index 0fb243e1f..8db229c1d 100644
--- a/.github/workflows/benchmark.yml
+++ b/.github/workflows/benchmark.yml
@@ -22,7 +22,32 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - name: Checkout base branch
+        uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.base.sha }}
+          fetch-depth: 0
+
+      - name: Use Node.js '16.15.0'
+        uses: actions/setup-node@v2
+        with:
+          node-version: "16.15.0"
+          cache: "npm"
+
+      - name: 📦 Install dependencies
+        run: npm ci
+
+      - name: 🏗️ Build contract artifacts
+        run: npx hardhat compile --force
+
+      - name: 🧪 Run Benchmark tests
+        # Rename the file to be able to generate benchmark JSON report
+        run: |
+          npm run test:benchmark
+          mv ./gas_benchmark_result.json ./gas_benchmark_before.json
+
+      - name: Checkout current branch
+        uses: actions/checkout@v3
 
       - name: Use Node.js '16.15.0'
         uses: actions/setup-node@v2
@@ -34,14 +59,22 @@ jobs:
         run: npm ci
 
       - name: 🏗️ Build contract artifacts
-        run: npx hardhat compile
+        # Clean artifacts to ensure we generate a clean build
+        run: |
+          npm run clean
+          npx hardhat compile --force
 
       - name: 🧪 Run Benchmark tests
-        run: npm run test:benchmark
+        run: |
+          npm run test:benchmark
+          mv ./gas_benchmark_result.json ./gas_benchmark_after.json
 
       - name: 📊 Generate Benchmark Report
+        run: npx hardhat gas-benchmark --compare ./gas_benchmark_after.json --against ./gas_benchmark_before.json
+
+      - name: 💬 Add Gas Report as comment in PR
         uses: peter-evans/create-or-update-comment@v2
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           issue-number: ${{ github.event.pull_request.number }}
-          body-file: "./benchmark.md"
+          body-file: "./gas_benchmark.md"