create-tests

Create Test Suite for LangGraph

Generate comprehensive pytest tests for LangGraph workflows including state tests, node unit tests, and integration tests with mocked LLMs.

Instructions for Claude

1. Analyze Target Graph

Read the graph file to identify:

• State schema (TypedDict definition)
• Node functions
• Edge connections
• Conditional routing logic

Use Grep to find:

• State class definition
• Node function definitions
• workflow.add_node() calls
• workflow.add_edge() and workflow.add_conditional_edges() calls

2. Gather Test Requirements

Ask user:

• Coverage level (basic or comprehensive)
• Whether to mock LLM calls (default: yes)
• Whether to generate integration tests (default: yes)

3. Generate Test Structure

Create:

tests/
├── __init__.py
├── conftest.py          # Fixtures
├── test_state.py        # State schema tests
├── test_nodes.py        # Node unit tests
├── test_graph.py        # Integration tests
└── fixtures/
    └── mock_data.py     # Test data

4. Generate conftest.py

import pytest
from unittest.mock import Mock

@pytest.fixture
def mock_llm():
    \"\"\"Mock LLM for testing.\"\"\"
    mock = Mock()
    mock.invoke.return_value = Mock(content="Mocked response")
    return mock

@pytest.fixture
def sample_state():
    \"\"\"Sample state for testing.\"\"\"
    return {
        "messages": [],
        "current_step": "start"
    }

5. Generate test_state.py

from src.state import {StateName}

def test_state_structure():
    \"\"\"Test state accepts valid data.\"\"\"
    state = {StateName}(
        messages=[],
        current_step="start"
    )
    assert isinstance(state["messages"], list)

def test_state_validation():
    \"\"\"Test state validation logic.\"\"\"
    # Add validation tests

6. Generate test_nodes.py

For each node, create:

def test_{node_name}(mock_llm, monkeypatch, sample_state):
    \"\"\"Test {node_name} node with mocked LLM.\"\"\"
    monkeypatch.setattr('src.nodes.llm', mock_llm)

    result = {node_name}(sample_state)

    assert "expected_field" in result
    mock_llm.invoke.assert_called_once()