ai-statement.yml

# Checks that a pull request fills in the "AI assistance" section of the template
# (CONTRIBUTING.md, "AI-assisted contributions"). It reads the description only and
# runs no code from the pull request.
name: AI statement

on:
  pull_request:
    branches: [ master ]
    types: [ opened, edited, synchronize, reopened ]

permissions:
  contents: read

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  ai-statement:
    if: github.event.pull_request.user.login != 'dependabot[bot]'
    runs-on: ubuntu-latest
    steps:
      # The description is passed as an environment variable, never pasted into the
      # script, so text in it cannot run as code.
      - name: Check the AI assistance section
        env:
          PR_BODY: ${{ github.event.pull_request.body }}
        shell: python
        run: |
          import os, re, sys

          body = os.environ.get("PR_BODY") or ""
          none = re.search(r"^- \[[xX]\] No AI tools were used", body, re.M)
          used = re.search(r"^- \[[xX]\] AI tools were used, and I \(a human\) have read every changed line", body, re.M)
          tools = re.search(r"^Tools used and for which parts:[ \t]*(\S.*)?$\n?((?:(?!^#).*\n?)*)", body, re.M)
          described = bool(tools and ((tools.group(1) or "") + tools.group(2)).strip())
          if bool(none) == bool(used):
              sys.exit("Tick exactly one box in the 'AI assistance' section of the pull request description "
                       "(see CONTRIBUTING.md, 'AI-assisted contributions').")
          if used and not described:
              sys.exit("Say which AI tools were used and for which parts, under 'Tools used and for which parts:'.")
          print("AI assistance section filled in.")