name: "Mutation Test (manual)"

# Smoke test for mutation testing. Manually triggered only — never on PR/push.
# Runs mutmut against the scope configured in [tool.mutmut] in pyproject.toml
# (currently a single file, ~186 LOC). Expected runtime: ~5-15 minutes.
#
# Uploads the mutmut cache + a text summary as a workflow artifact. Failures
# do not block anything because nothing depends on this workflow.

on:
  workflow_dispatch:
  # TEMPORARY: lets us iterate on this workflow before it lands on the default
  # branch (workflow_dispatch only works once the file is on default). Remove
  # this push: block before merging — final state should be workflow_dispatch
  # only.
  push:
    branches:
      - litellm_mutation_test_smoke

permissions:
  contents: read

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

jobs:
  mutation:
    name: Run mutmut
    runs-on: ubuntu-latest
    timeout-minutes: 60

    steps:
      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
        with:
          persist-credentials: false

      - name: Set up Python
        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
        with:
          python-version: "3.12"

      - name: Set up uv
        uses: astral-sh/setup-uv@37802adc94f370d6bfd71619e3f0bf239e1f3b78 # v7
        with:
          version: "0.10.9"

      - name: Cache uv dependencies
        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
        with:
          path: |
            ~/.cache/uv
            .venv
          key: ${{ runner.os }}-uv-${{ hashFiles('uv.lock') }}
          restore-keys: |
            ${{ runner.os }}-uv-

      - name: Install dependencies
        run: |
          uv sync --frozen --group ci --group proxy-dev --extra google --extra proxy --extra semantic-router

      - name: Generate Prisma client
        env:
          PRISMA_BINARY_CACHE_DIR: ${{ runner.temp }}/prisma-cache
        run: |
          uv run --no-sync prisma generate --schema litellm/proxy/schema.prisma

      # mutmut 3.x runs tests inside a `mutants/` sandbox where it injects
      # mutation trampolines. uv installs the project as editable by default,
      # which puts the original source dir on sys.path via a .pth file and
      # shadows the sandbox copy — so tests would never exercise the mutated
      # code. Reinstalling non-editable removes the .pth shadow.
      - name: Reinstall litellm non-editable (so mutants/ is not shadowed)
        run: |
          uv pip uninstall litellm
          uv pip install . --no-deps

      - name: Run mutmut
        env:
          # Make the mutants/ sandbox win over site-packages on sys.path so the
          # trampolined files are imported instead of the installed copy.
          PYTHONPATH: ${{ github.workspace }}/mutants
        run: |
          mkdir -p mutants
          uv run --no-sync --with mutmut==3.5.0 mutmut run

      - name: Show mutmut results
        if: always()
        run: |
          uv run --no-sync --with mutmut==3.5.0 mutmut results | tee mutmut-results.txt

      - name: Upload mutmut artifacts
        if: always()
        uses: actions/upload-artifact@4cec3d8aa04e39d1a68397de0c4cd6fb9dce8ec1 # v4.6.1
        with:
          name: mutmut-${{ github.run_id }}-${{ github.run_attempt }}
          path: |
            mutmut-results.txt
            mutmut-stats.json
            mutmut-cache.json
          if-no-files-found: warn
          retention-days: 14