Broken Flask-SQLAlchemy & py.test example

app.py

from flask import Flask, Blueprint
from flask.ext.restful import Api
from models import db

api = Api(prefix='/api')
api_bp = Blueprint('api_bp', __name__)
api.init_app(api_bp)

def create_app(config_name):
    app = Flask(__name__)
    app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///test.db'
    app.config['SQLALCHEMY_ECHO'] = False
    app.config['TESTING'] = True
    db.init_app(app)
    app.register_blueprint(api_bp)
    return app

conftest.py

import pytest
import sys
import os

from app import create_app
from app import db as _db

DB_PATH = 'test.db'
DB_URI = 'sqlite:///{0}'.format(DB_PATH)

@pytest.yield_fixture(scope='session')
def app(request):
    """Session-wide test `Flask` application."""

    app = create_app('testing')

    # Establish an application context before running the tests.
    ctx = app.app_context()
    ctx.push()

    yield app

    # app teardown here
    ctx.pop()

@pytest.yield_fixture(scope='session')
def db(app, request):
    """Session-wide test database."""

    if os.path.exists(DB_PATH):
        os.remove(DB_PATH)

    # NOTE: app, is required to keep the db in the right Flask app context
    _db.app = app
    _db.create_all()

    yield _db

    # Finalize test here
    _db.drop_all()
    if os.path.exists(DB_PATH):
        os.remove(DB_PATH)


@pytest.yield_fixture(scope='function')
def session(app, db):
    connection = db.engine.connect()
    transaction = connection.begin()

    #options = dict(bind=connection, binds={})
    options = dict(bind=connection)
    session = db.create_scoped_session(options=options)

    yield session

    # Finalize test here
    transaction.rollback()
    connection.close()
    session.remove()

models.py

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64))

    def __init__(self, name):
        self.name = name

    def __repr__(self):
        return u'<User {0}>'.format(self.name)

test_db.py

from models import User

def test_user_schema1(session):
    person_name = 'Fran Clan'
    uu = User(name=person_name)
    session.add(uu)
    session.commit()

    assert uu.id==1
    assert uu.name==person_name

def test_user_schema2(session):
    person_name = 'Stan Clan'
    uu = User(name=person_name)
    session.add(uu)
    session.commit()

    assert uu.id==1
    assert uu.name==person_name