langchain-ci-integration

# LangChain CI Integration ## Overview Configure comprehensive CI/CD pipelines for LangChain applications with testing, linting, and deployment automation. ## Prerequisites - GitHub repository with Actions enabled - LangChain application with test suite - API keys for testing (stored as GitHub Secrets) ## Instructions ### Step 1: Create GitHub Actions Workflow ```yaml # .github/workflows/langchain-ci.yml name: LangChain CI on: push: branches: [main, develop] pull_request: branches: [main] env: PYTHON_VERSION: "3.11" jobs: lint: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - name: Set up Python uses: actions/setup-python@v5 with: python-version: ${{ env.PYTHON_VERSION }} - name: Install dependencies run: | pip install ruff mypy - name: Lint with Ruff run: ruff check . - name: Type check with mypy run: mypy src/ test-unit: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - name: Set up Python uses: actions/setup-python@v5 with: python-version: ${{ env.PYTHON_VERSION }} - name: Install dependencies run: | pip install -e ".[dev]" - name: Run unit tests run: | pytest tests/unit -v --cov=src --cov-report=xml - name: Upload coverage uses: codecov/codecov-action@v4 with: files: coverage.xml test-integration: runs-on: ubuntu-latest needs: [lint, test-unit] # Only run on main branch or manual trigger if: github.ref == 'refs/heads/main' || github.event_name == 'workflow_dispatch' steps: - uses: actions/checkout@v4 - name: Set up Python uses: actions/setup-python@v5 with: python-version: ${{ env.PYTHON_VERSION }} - name: Install dependencies run: | pip install -e ".[dev]" - name: Run integration tests env: OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }} run: | pytest tests/integration -v -m integration ``` ### Step 2: Configure Test Markers ```python # pyproject.toml [tool.pytest.ini_options] markers = [ "unit: Unit tests (no external API calls)", "integration: Integration tests (requires API keys)", "slow: Slow tests (skip in fast mode)", ] asyncio_mode = "auto" testpaths = ["tests"] ``` ### Step 3: Create Mock Fixtures ```python # tests/conftest.py import pytest from unittest.mock import MagicMock, AsyncMock from langchain_core.messages import AIMessage @pytest.fixture def mock_llm(): """Mock LLM for unit tests.""" mock = MagicMock() mock.invoke.return_value = AIMessage(content="Mock response") mock.ainvoke = AsyncMock(return_value=AIMessage(content="Mock response")) return mock @pytest.fixture def mock_chain(mock_llm): """Mock chain for testing.""" from langchain_core.prompts import ChatPromptTemplate from langchain_core.output_parsers import StrOutputParser prompt = ChatPromptTemplate.from_template("{input}") return prompt | mock_llm | StrOutputParser() ``` ### Step 4: Add Pre-commit Hooks ```yaml # .pre-commit-config.yaml repos: - repo: https://github.com/astral-sh/ruff-pre-commit rev: v0.1.6 hooks: - id: ruff args: [--fix] - id: ruff-format - repo: https://github.com/pre-commit/mirrors-mypy rev: v1.7.1 hooks: - id: mypy additional_dependencies: - langchain-core - pydantic ``` ### Step 5: Add Deployment Stage ```yaml # Add to .github/workflows/langchain-ci.yml deploy: runs-on: ubuntu-latest needs: [test-integration] if: github.ref == 'refs/heads/main' environment: production steps: - uses: actions/checkout@v4 - name: Deploy to Cloud Run uses: google-github-actions/deploy-cloudrun@v2 with: service: langchain-api source: . env_vars: | LANGCHAIN_PROJECT=production ``` ## Output - GitHub Actions workflow with lint, test, deploy stages - pytest configuration with markers - Mock fixtures for unit testing - Pre-commit hooks for code quality ## Examples ### Running Tests Locally ```bash # Run unit tests only (fast) pytest tests/unit -v # Run with coverage pytest tests/unit --cov=src --cov-report=html # Run integration tests (requires API key) OPENAI_API_KEY=sk-... pytest tests/integration -v -m integration # Skip slow tests pytest tests/ -v -m "not slow" ``` ### Integration Test Example ```python # tests/integration/test_chain.py import pytest from langchain_openai import ChatOpenAI from langchain_core.prompts import ChatPromptTemplate @pytest.mark.integration def test_real_chain_invocation(): """Test with real LLM (requires API key).""" llm = ChatOpenAI(model="gpt-4o-mini", temperature=0) prompt = ChatPromptTemplate.from_template("Say exactly: {word}") chain = prompt | llm result = chain.invoke({"word": "hello"}) assert "hello" in result.content.lower() ``` ## Error Handling | Error | Cause | Solution | |-------|-------|----------| | Secret Not Found | Missing GitHub secret | Add OPENAI_API_KEY to repository secrets | | Rate Limit in CI | Too many API calls | Use mocks for unit tests, limit integration tests | | Timeout | Slow tests | Add timeout markers, parallelize tests | | Import Error | Missing dev dependencies | Ensure `.[dev]` extras installed | ## Resources - [GitHub Actions Documentation](https://docs.github.com/en/actions) - [pytest Documentation](https://docs.pytest.org/) - [Pre-commit](https://pre-commit.com/) ## Next Steps Proceed to `langchain-deploy-integration` for deployment configuration.