test_base_model.py

#!/usr/bin/python3
"""Test BaseModel for expected behavior and documentation"""
from datetime import datetime
import inspect
import models
import os
import pep8 as pycodestyle
import time
import unittest
from unittest import mock
BaseModel = models.base_model.BaseModel
module_doc = models.base_model.__doc__


class TestBaseModelDocs(unittest.TestCase):
    """Tests to check the documentation and style of BaseModel class"""

    @classmethod
    def setUpClass(self):
        """Set up for docstring tests"""
        self.base_funcs = inspect.getmembers(BaseModel, inspect.isfunction)

    def test_pep8_conformance(self):
        """Test that models/base_model.py conforms to PEP8."""
        for path in ['models/base_model.py',
                     'tests/test_models/test_base_model.py']:
            with self.subTest(path=path):
                errors = pycodestyle.Checker(path).check_all()
                self.assertEqual(errors, 0)

    def test_module_docstring(self):
        """Test for the existence of module docstring"""
        self.assertIsNot(module_doc, None,
                         "base_model.py needs a docstring")
        self.assertTrue(len(module_doc) > 1,
                        "base_model.py needs a docstring")

    def test_class_docstring(self):
        """Test for the BaseModel class docstring"""
        self.assertIsNot(BaseModel.__doc__, None,
                         "BaseModel class needs a docstring")
        self.assertTrue(len(BaseModel.__doc__) >= 1,
                        "BaseModel class needs a docstring")

    def test_func_docstrings(self):
        """Test for the presence of docstrings in BaseModel methods"""
        for func in self.base_funcs:
            with self.subTest(function=func):
                self.assertIsNot(
                    func[1].__doc__,
                    None,
                    "{:s} method needs a docstring".format(func[0])
                )
                self.assertTrue(
                    len(func[1].__doc__) > 1,
                    "{:s} method needs a docstring".format(func[0])
                )


class TestBaseModel(unittest.TestCase):
    """Test the BaseModel class"""
    def test_instantiation(self):
        """Test that object is correctly created"""
        inst = BaseModel()
        self.assertIs(type(inst), BaseModel)
        inst.name = "Holberton"
        inst.number = 89
        attrs_types = {
            "id": str,
            "created_at": datetime,
            "updated_at": datetime,
            "name": str,
            "number": int
        }
        for attr, typ in attrs_types.items():
            with self.subTest(attr=attr, typ=typ):
                self.assertIn(attr, inst.__dict__)
                self.assertIs(type(inst.__dict__[attr]), typ)
        self.assertEqual(inst.name, "Holberton")
        self.assertEqual(inst.number, 89)

    def test_datetime_attributes(self):
        """Test that two BaseModel instances have different datetime objects
        and that upon creation have identical updated_at and created_at
        value."""
        tic = datetime.now()
        inst1 = BaseModel()
        toc = datetime.now()
        self.assertTrue(tic <= inst1.created_at <= toc)
        time.sleep(1e-4)
        tic = datetime.now()
        inst2 = BaseModel()
        toc = datetime.now()
        self.assertTrue(tic <= inst2.created_at <= toc)
        self.assertEqual(inst1.created_at, inst1.updated_at)
        self.assertEqual(inst2.created_at, inst2.updated_at)
        self.assertNotEqual(inst1.created_at, inst2.created_at)
        self.assertNotEqual(inst1.updated_at, inst2.updated_at)

    def test_uuid(self):
        """Test that id is a valid uuid"""
        inst1 = BaseModel()
        inst2 = BaseModel()
        for inst in [inst1, inst2]:
            uuid = inst.id
            with self.subTest(uuid=uuid):
                self.assertIs(type(uuid), str)
                self.assertRegex(uuid,
                                 '^[0-9a-f]{8}-[0-9a-f]{4}'
                                 '-[0-9a-f]{4}-[0-9a-f]{4}'
                                 '-[0-9a-f]{12}$')
        self.assertNotEqual(inst1.id, inst2.id)

    def test_to_dict(self):
        """Test conversion of object attributes to dictionary for json"""
        my_model = BaseModel()
        my_model.name = "Holberton"
        my_model.my_number = 89
        d = my_model.to_dict()
        expected_attrs = ["id",
                          "created_at",
                          "updated_at",
                          "name",
                          "my_number",
                          "__class__"]
        self.assertCountEqual(d.keys(), expected_attrs)
        self.assertEqual(d['__class__'], 'BaseModel')
        self.assertEqual(d['name'], "Holberton")
        self.assertEqual(d['my_number'], 89)
        self.assertNotIn('_sa_instance_state', d)

    def test_to_dict_values(self):
        """test that values in dict returned from to_dict are correct"""
        t_format = "%Y-%m-%dT%H:%M:%S.%f"
        bm = BaseModel()
        new_d = bm.to_dict()
        self.assertEqual(new_d["__class__"], "BaseModel")
        self.assertEqual(type(new_d["created_at"]), str)
        self.assertEqual(type(new_d["updated_at"]), str)
        self.assertEqual(new_d["created_at"], bm.created_at.strftime(t_format))
        self.assertEqual(new_d["updated_at"], bm.updated_at.strftime(t_format))

    def test_str(self):
        """test that the str method has the correct output"""
        inst = BaseModel()
        string = "[BaseModel] ({}) {}".format(inst.id, inst.__dict__)
        self.assertEqual(string, str(inst))

    @mock.patch('models.storage')
    def test_save(self, mock_storage):
        """Test that save method updates `updated_at` and calls
        `storage.save`"""
        inst = BaseModel()
        old_created_at = inst.created_at
        old_updated_at = inst.updated_at
        inst.save()
        new_created_at = inst.created_at
        new_updated_at = inst.updated_at
        self.assertNotEqual(old_updated_at, new_updated_at)
        self.assertEqual(old_created_at, new_created_at)
        self.assertTrue(mock_storage.new.called)
        self.assertTrue(mock_storage.save.called)