import pytest
from app import create_app

@pytest.fixture
def client():
    app = create_app()
    app.config['TESTING'] = True
    return app.test_client()

def test_index(client):
    rv = client.get('/')
    assert rv.status_code == 200
    json_data = rv.get_json()
    assert json_data['message'] == 'Hello, Flask!'