feat(ci): add gas-benching workflow (#204)

Resolves #169

.github/workflows/gas-bench.yml

@@ -0,0 +1,45 @@
+name: gas-bench
+# This workflow checks that the compiled wasm binary of every example contract
+# can be deployed to Arbitrum Stylus.
+permissions:
+  contents: read
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+env:
+  CARGO_TERM_COLOR: always
+jobs:
+  required:
+    name: gas usage report
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: set up rust
+        uses: dtolnay/rust-toolchain@master
+        id: toolchain
+        with:
+          target: wasm32-unknown-unknown
+          components: rust-src
+          toolchain: nightly-2024-01-01
+
+      - uses: Swatinem/rust-cache@v2
+        with:
+          cache-on-failure: true
+
+      - name: install solc
+        run: |
+          curl -LO https://github.com/ethereum/solidity/releases/download/v0.8.21/solc-static-linux
+          sudo mv solc-static-linux /usr/bin/solc
+          sudo chmod a+x /usr/bin/solc
+
+      - name: setup nitro node
+        run: ./scripts/nitro-testnode.sh -d -i
+      - name: run benches
+        run: |
+          export NIGHTLY_TOOLCHAIN=${{steps.toolchain.outputs.name}}
+          ./scripts/bench.sh

scripts/bench.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+set -e
+
+MYDIR=$(realpath "$(dirname "$0")")
+cd "$MYDIR"
+cd ..
+
+NIGHTLY_TOOLCHAIN=${NIGHTLY_TOOLCHAIN:-nightly}
+cargo +"$NIGHTLY_TOOLCHAIN" build --release --target wasm32-unknown-unknown -Z build-std=std,panic_abort -Z build-std-features=panic_immediate_abort
+
+export RPC_URL=http://localhost:8547
+cargo run --release -p benches
+echo "Finished running benches!"