✅ test(pytest): add comprehensive pytest setup and tests for LangGraph agent

- Add .vscode/settings.json to configure pytest settings
- Extend Makefile with granular test targets: unit, integration, e2e, all, watch modes
- Add linting improvements and new development commands in Makefile for dev and dev_ui
- Configure pytest asyncio options in pyproject.toml
- Create pytest conftest.py fixture to load environment variables and skip tests if missing keys
- Implement detailed end-to-end tests in tests/e2e_tests/test_react_agent_e2e.py to cover:
  - Simple question answering
  - Streaming responses with tool usage detection
  - Thread and conversation management
  - Concurrent request handling
  - API error handling and assistant listing
  - Streaming modes testing
- Add integration test in tests/integration_tests/test_graph.py validating agent responses on LangChain founder
- Ensure tests use asyncio and properly check expected outputs for correctness

Author: webup

.vscode/settings.json

@@ -0,0 +1,7 @@
+{
+    "python.testing.pytestArgs": [
+        "tests"
+    ],
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestEnabled": true
+}

Makefile

@@ -1,22 +1,56 @@
-.PHONY: all format lint test tests test_watch integration_tests docker_tests help extended_tests
+.PHONY: all format lint test test_unit test_integration test_e2e test_all test_watch test_watch_unit test_watch_integration test_watch_e2e test_profile extended_tests dev dev_ui
 
 # Default target executed when no arguments are given to make.
 all: help
 
-# Define a variable for the test file path.
-TEST_FILE ?= tests/unit_tests/
+######################
+# TESTING
+######################
 
+# Legacy test command (defaults to unit tests for backward compatibility)
 test:
-	python -m pytest $(TEST_FILE)
+	python -m pytest tests/unit_tests/
+
+# Specific test targets
+test_unit:
+	python -m pytest tests/unit_tests/
+
+test_integration:
+	python -m pytest tests/integration_tests/
+
+test_e2e:
+	python -m pytest tests/e2e_tests/
 
-test_watch:
+test_all:
+	python -m pytest tests/
+
+# Watch mode for tests
+test_watch: test_watch_unit
+
+test_watch_unit:
 	python -m ptw --snapshot-update --now . -- -vv tests/unit_tests
 
+test_watch_integration:
+	python -m ptw --snapshot-update --now . -- -vv tests/integration_tests
+
+test_watch_e2e:
+	python -m ptw --snapshot-update --now . -- -vv tests/e2e_tests
+
 test_profile:
 	python -m pytest -vv tests/unit_tests/ --profile-svg
 
 extended_tests:
-	python -m pytest --only-extended $(TEST_FILE)
+	python -m pytest --only-extended tests/unit_tests/
+
+######################
+# DEVELOPMENT
+######################
+
+dev:
+	uv run langgraph dev --no-browser
+
+dev_ui:
+	uv run langgraph dev
 
 
 ######################
@@ -32,13 +66,25 @@ lint_package: PYTHON_FILES=src
 lint_tests: PYTHON_FILES=tests
 lint_tests: MYPY_CACHE=.mypy_cache_test
 
-lint lint_diff lint_package lint_tests:
+lint:
+	python -m ruff check .
+	python -m ruff format src --diff
+	python -m ruff check --select I src
+	python -m mypy --strict src
+	mkdir -p .mypy_cache && python -m mypy --strict src --cache-dir .mypy_cache
+
+lint_diff lint_package:
 	python -m ruff check .
 	[ "$(PYTHON_FILES)" = "" ] || python -m ruff format $(PYTHON_FILES) --diff
 	[ "$(PYTHON_FILES)" = "" ] || python -m ruff check --select I $(PYTHON_FILES)
 	[ "$(PYTHON_FILES)" = "" ] || python -m mypy --strict $(PYTHON_FILES)
 	[ "$(PYTHON_FILES)" = "" ] || mkdir -p $(MYPY_CACHE) && python -m mypy --strict $(PYTHON_FILES) --cache-dir $(MYPY_CACHE)
 
+lint_tests:
+	python -m ruff check tests --fix
+	python -m ruff format tests
+	# Skip mypy for tests to allow more flexible typing
+
 format format_diff:
 	ruff format $(PYTHON_FILES)
 	ruff check --select I --fix $(PYTHON_FILES)
@@ -55,10 +101,24 @@ spell_fix:
 
 help:
 	@echo '----'
-	@echo 'format                       - run code formatters'
-	@echo 'lint                         - run linters'
-	@echo 'test                         - run unit tests'
-	@echo 'tests                        - run unit tests'
-	@echo 'test TEST_FILE=<test_file>   - run all tests in file'
+	@echo 'DEVELOPMENT:'
+	@echo 'dev                          - run langgraph dev without browser'
+	@echo 'dev_ui                       - run langgraph dev with browser'
+	@echo ''
+	@echo 'TESTING:'
+	@echo 'test                         - run unit tests (default)'
+	@echo 'test_unit                    - run unit tests only'
+	@echo 'test_integration             - run integration tests only'
+	@echo 'test_e2e                     - run e2e tests only'
+	@echo 'test_all                     - run all tests (unit + integration + e2e)'
 	@echo 'test_watch                   - run unit tests in watch mode'
+	@echo 'test_watch_unit              - run unit tests in watch mode'
+	@echo 'test_watch_integration       - run integration tests in watch mode'
+	@echo 'test_watch_e2e               - run e2e tests in watch mode'
+	@echo ''
+	@echo 'CODE QUALITY:'
+	@echo 'format                       - run code formatters'
+	@echo 'lint                         - run linters (ruff + mypy on src/)'
+	@echo 'lint_tests                   - run linters on tests (ruff only, no mypy)'
+	@echo 'lint_package                 - run linters on src/ only'
 

pyproject.toml

@@ -60,8 +60,15 @@ lint.ignore = [
 [tool.ruff.lint.pydocstyle]
 convention = "google"
 
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
+
 [dependency-groups]
 dev = [
     "langgraph-cli[inmem]>=0.1.71",
     "pytest>=8.3.5",
+    "pytest-asyncio>=0.23.0",
+    "langgraph-sdk>=0.1.0",
+    "mypy>=1.17.1",
 ]

tests/conftest.py

@@ -0,0 +1,26 @@
+"""Pytest configuration and shared fixtures."""
+
+import os
+from pathlib import Path
+
+import pytest
+from dotenv import load_dotenv
+
+
+@pytest.fixture(scope="session", autouse=True)
+def load_env():
+    """Load environment variables from .env file for all tests."""
+    # Find the project root (where .env is located)
+    project_root = Path(__file__).parent.parent
+    env_file = project_root / ".env"
+
+    if env_file.exists():
+        load_dotenv(env_file)
+
+    # Ensure required environment variables are available for tests
+    # You can add fallback values or skip tests if keys are missing
+    required_keys = ["OPENAI_API_KEY", "TAVILY_API_KEY"]
+    missing_keys = [key for key in required_keys if not os.getenv(key)]
+
+    if missing_keys:
+        pytest.skip(f"Missing required environment variables: {missing_keys}")

tests/e2e_tests/__init__.py

@@ -0,0 +1 @@
+"""End-to-end tests for the LangGraph ReAct agent."""