gas-snapshot.yml

name: snapshot gas

on:
  workflow_dispatch:
  pull_request:

env:
  FOUNDRY_PROFILE: ir

jobs:
  snapshot-gas:
    name: Diff against gas snapshot
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v3
        with:
          submodules: recursive

      - name: Install Foundry
        uses: foundry-rs/foundry-toolchain@v1
        with:
          version: "nightly-de33b6af53005037b463318d2628b5cfcaf39916"

      - name: Install dependencies
        run: forge install

      - name: Diff gas snapshot against baseline
        run: |
          set -euo pipefail
          # grep -E '^test'  -- skip over test results, just get diffs
          forge snapshot --diff \
            | grep -E '^test'   \
            | tee .gas-snapshot.new
        env:
          MAINNET_RPC_URL: ${{ secrets.MAINNET_RPC_URL }}

      - name: Check diff tolerance
        run: |
          set -euo pipefail
          # 1. skip over diffs of 0 gas (do not fail if no matches)
          # 2. skip over negative diffs (do not fail if no matches)
          # 3. remove ANSI color / style escape sequences
          # 4. extract absolute (not percentage) gas diffs
          # 5. pluck any diffs that exceed an absolute tolerance threshold
          #    and exit non-zero (failure) if any such diff is found
          { grep -Ev 'gas: 0' .gas-snapshot.new || true; }  \
            | { grep -Ev '\-[0-9]+' || true; }              \
            | sed -Ee 's/\x1b\[[0-9;]*m//g'                 \
                  -Ee 's/(.+)\(\) \(gas: ([0-9]+).+/\1 \2/' \
            | awk '{ if ($2 > ENVIRON["GAS_DIFF_THRESHOLD"]) { print; failures++ } } END { if (failures > 0) { print $failures; exit 1 } else { print "ok." } }'
        env:
          # gas diff check should fail if any gas diff exceeds threshold
          GAS_DIFF_THRESHOLD: 5000