it fails always in same test case "Create a taco and redirect to the home page"

from flask import Flask, g, render_template, flash, redirect, url_for
from flask.ext.bcrypt import check_password_hash
from flask.ext.login import (LoginManager, login_user,
                             logout_user, login_required, current_user)

import forms
import models

DEBUG = True
PORT = 8000
HOST = '0.0.0.0'

app = Flask(__name__)
app.secret_key = 'top_secret'

login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = 'login'


@login_manager.user_loader
def load_user(userid):
    try:
        return models.User.get(models.User.id == userid)
    except models.DoesNotExist:
        return None


@app.before_request
def before_request():
    """Connect to the database before each request."""
    g.db = models.DATABASE
    g.db.connect()
    g.user = current_user


@app.after_request
def after_request(response):
    """Close the database connection after each request."""
    g.db.close
    return response


@app.route('/register', methods=('GET', 'POST'))
def register():
    form = forms.RegisterForm()
    if form.validate_on_submit():
        flash("Yay, you registered!", "success")
        models.User.create_user(
            email=form.email.data,
            password=form.password.data
        )
        return redirect(url_for('index'))
    return render_template('register.html', form=form)


@app.route('/login', methods=('GET', 'POST'))
def login():
    form = forms.LoginForm()
    if form.validate_on_submit():
        try:
            user = models.User.get(models.User.email == form.email.data)
        except models.DoesNotExist:
            flash("Email is incompatible", "error")
        else:
            if check_password_hash(user.password, form.password.data):
                login_user(user)
                flash("You are logged in", "success")
                return redirect(url_for('index'))
            else:
                flash("Password does not match", "error")
    return render_template('login.html', form=form)


@app.route('/logout')
@login_required
def logout():
    logout_user()
    flash("You've been logged out! Come back soon!", "success")
    return redirect(url_for('index'))


@app.route('/new_taco', methods=('GET', 'POST'))
@login_required
def taco():
    form = forms.TacoForm()
    if form.validate_on_submit():
        models.Taco.create(user=g.user._get_current_object(),
                           protein=form.protein.data,
                           shell=form.shell.data,
                           cheese=form.cheese.data,
                           extras=form.extras.data.strip()
                           )
        flash("Your taco has been added!!", "success")
        return redirect(url_for('index'))
    return render_template('taco.html', form=form)


@app.route('/')
def index():
    tacos = models.Taco.select().limit(10)
    return render_template('index.html', tacos=tacos)


if __name__ == '__main__':
    models.initialize()
    try:
        with models.DATABASE.transaction():
            models.User.create_user(
                email='a@a.com',
                password='123123'
            )
    except ValueError:
        pass

import datetime

from flask.ext.bcrypt import generate_password_hash
from flask.ext.login import UserMixin
from peewee import *

DATABASE = SqliteDatabase('taco.db')


class User(UserMixin, Model):
    email = CharField(unique=True)
    password = CharField(max_length=100)

    class Meta:
        database = DATABASE

    def get_tacos(self):
        return Taco.select().where(Taco.user == self)

    def get_stream(self):
        return Taco.select().where(
            (Taco.user == self)
        )

    @classmethod
    def create_user(cls, email, password):
        try:
            cls.create(
                email=email,
                password=generate_password_hash(password))
        except IntegrityError:
            raise ValueError("User already exists")


class Taco(Model):
    protein = CharField()
    shell = CharField()
    cheese = BooleanField(default=True)
    extras = TextField()
    user = ForeignKeyField(
        rel_model=User,
        related_name='tacos'
    )

    class Meta:
        database = DATABASE


def initialize():
    DATABASE.connect()
    DATABASE.create_tables([User, Taco], safe=True)
    DATABASE.close()

from flask_wtf import Form
from wtforms import StringField, PasswordField, BooleanField, TextAreaField
from wtforms.validators import (DataRequired, ValidationError, Email,
                                Length, EqualTo)

from models import User


def email_exists(form, field):
    if User.select().where(User.email == field.data).exists():
        raise ValidationError('User with that email already exists')


class RegisterForm(Form):
    email = StringField(
        'Email',
        validators=[
            DataRequired(),
            Email(),
            email_exists,
        ])
    password = PasswordField(
        'Password',
        validators=[
            DataRequired(),
            Length(min=2),
            EqualTo('password2', message='Passwords must match')
        ])
    password2 = PasswordField(
        'Confirm Password',
        validators=[DataRequired()]
    )


class LoginForm(Form):
    email = StringField('Email', validators=[DataRequired(), Email()])
    password = PasswordField('Password', validators=[DataRequired()])


class TacoForm(Form):
    protein = StringField('Protein')
    shell = StringField('Shell', validators=[DataRequired()])
    cheese = BooleanField('Cheese')
    extras = TextAreaField("Any extras?")