kevinya

本篇教學的部分是
如何自動化的測試Django web application
從之前的文章一步一步進行過來的話，將會在程式碼看到這個檔案locallibrary\catalog\tests.py
不用懷疑，將他刪除(或是重新命名也可以)！

接著打開此檔案/catalog/tests/test_models.py，內容加入：

from django.test import TestCase

# Create your tests here.

並且將以下的class加入到同一個檔案中：

class YourTestClass(TestCase):

    @classmethod
	#執行下面的method之前，會先執行一次setUpTestData(cls)來新增假資料
    def setUpTestData(cls):
        print("setUpTestData: Run once to set up non-modified data for all class methods.")
        pass

    def setUp(self):
	#下面每個method測試之前都會執行一次setup(self)，作為初始化
        print("setUp: Run once for every test method to setup clean data.")
        pass

    def test_false_is_false(self):
        print("Method: test_false_is_false.")
        self.assertFalse(False)

    def test_false_is_true(self):
        print("Method: test_false_is_true.")
        self.assertTrue(False)

    def test_one_plus_one_equals_two(self):
        print("Method: test_one_plus_one_equals_two.")
        self.assertEqual(1 + 1, 2)

接著於終端機執行下列指令就可以執行測試了：

python manage.py test

可以看到測試的結果有一項出錯，FAIL: test_false_is_true，當然false跟true是不同的，這是我們故意要讓他測試出錯的：

如果希望測試的output能顯示的詳細一點，可以把上面終端機的指令改為：

python manage.py test --verbosity 2

如果想執行一部分的測試就好，不要測試全部的話，可參考下面的終端機指令：
可以只測試某資料夾、或是某個檔案、或是某個TestClass、或是某個method

python manage.py test catalog.tests   # Run the specified module
python manage.py test catalog.tests.test_models  # Run the specified module
python manage.py test catalog.tests.test_models.YourTestClass # Run the specified class
python manage.py test catalog.tests.test_models.YourTestClass.test_one_plus_one_equals_two  # Run the specified method

將剛才的/catalog/tests/test_models.py的內容全部改為如下，正式開始測試Locallibrary網站：

from django.test import TestCase

# Create your tests here.

from catalog.models import Author

class AuthorModelTest(TestCase):

    @classmethod
    def setUpTestData(cls):
        #Set up non-modified objects used by all test methods
		#新增一筆假資料做測試
        Author.objects.create(first_name='Big', last_name='Bob')

    def test_first_name_label(self):
        author=Author.objects.get(id=1)
		#檢查欄位的別名是否有被改掉
        field_label = author._meta.get_field('first_name').verbose_name
        self.assertEquals(field_label,'first name')

    def test_date_of_death_label(self):
        author=Author.objects.get(id=1)		
        field_label = author._meta.get_field('date_of_death').verbose_name
        self.assertEquals(field_label,'died')

    def test_first_name_max_length(self):
        author=Author.objects.get(id=1)
		#檢查欄位的maxlength是否被改掉
        max_length = author._meta.get_field('first_name').max_length
        self.assertEquals(max_length,100)

    def test_object_name_is_last_name_comma_first_name(self):
        author=Author.objects.get(id=1)
		#檢查 資料表.tostring是否被改掉
        expected_object_name = '%s, %s' % (author.last_name, author.first_name)
        self.assertEquals(expected_object_name,str(author))

    def test_get_absolute_url(self):
        author=Author.objects.get(id=1)
        #This will also fail if the urlconf is not defined.
        self.assertEquals(author.get_absolute_url(),'/catalog/author/1')

並請再執行終端機指令測試一次，得到結果如下：
發現Died與died並不相同，因此測出一個錯誤！

接著示範測試forms.py的方式，首先在/catalog/tests/test_forms.py加入：
以下內容很簡單，因此就沒有註解

from django.test import TestCase

# Create your tests here.

import datetime
from django.utils import timezone
from catalog.forms import RenewBookForm

class RenewBookFormTest(TestCase):

    def test_renew_form_date_field_label(self):
        form = RenewBookForm()        
        self.assertTrue(form.fields['renewal_date'].label == None or form.fields['renewal_date'].label == 'renewal date')

    def test_renew_form_date_field_help_text(self):
        form = RenewBookForm()
        self.assertEqual(form.fields['renewal_date'].help_text,'Enter a date between now and 4 weeks (default 3).')

    def test_renew_form_date_in_past(self):
        date = datetime.date.today() - datetime.timedelta(days=1)
        form_data = {'renewal_date': date}
        form = RenewBookForm(data=form_data)
        self.assertFalse(form.is_valid())

    def test_renew_form_date_too_far_in_future(self):
        date = datetime.date.today() + datetime.timedelta(weeks=4) + datetime.timedelta(days=1)
        form_data = {'renewal_date': date}
        form = RenewBookForm(data=form_data)
        self.assertFalse(form.is_valid())

    def test_renew_form_date_today(self):
        date = datetime.date.today()
        form_data = {'renewal_date': date}
        form = RenewBookForm(data=form_data)
        self.assertTrue(form.is_valid())
        
    def test_renew_form_date_max(self):
        date = timezone.now() + datetime.timedelta(weeks=4)
        form_data = {'renewal_date': date}
        form = RenewBookForm(data=form_data)
        self.assertTrue(form.is_valid())

執行測試之後，發現沒有測出任何錯誤：

接著示範如何測試views.py，請於/catalog/tests/test_views.py加入下列內容：

from django.test import TestCase

# Create your tests here.

from catalog.models import Author
from django.urls import reverse
from django.contrib.auth.models import User #Required to login

class AuthorListViewTest(TestCase):

    @classmethod
    def setUpTestData(cls):
        #Create 13 authors for pagination tests
        number_of_authors = 13
        for author_num in range(number_of_authors):
            Author.objects.create(first_name='Christian %s' % author_num, last_name = 'Surname %s' % author_num,)

    #因為"all authors"網頁 = /catalog/authors/ 需要登入
    #因此新增使用者來登入
    def setUp(self):
        #Create two users
        test_user1 = User.objects.create_user(username='testuser1', password='12345') 
        test_user1.save()
        self.client.login(username='testuser1', password='12345')

    def test_view_url_exists_at_desired_location(self): 
        resp = self.client.get('/catalog/authors/') 
        self.assertEqual(resp.status_code, 200)  
           
    def test_view_url_accessible_by_name(self):
        resp = self.client.get(reverse('authors'))
        self.assertEqual(resp.status_code, 200)
        
    def test_view_uses_correct_template(self):
        resp = self.client.get(reverse('authors'))
        self.assertEqual(resp.status_code, 200)

        self.assertTemplateUsed(resp, 'catalog/author_list.html')
        
    def test_pagination_is_ten(self):
        resp = self.client.get(reverse('authors'))
        self.assertEqual(resp.status_code, 200)
        self.assertTrue('is_paginated' in resp.context)
        self.assertTrue(resp.context['is_paginated'] == True)
        self.assertTrue( len(resp.context['author_list']) == 10)

    def test_lists_all_authors(self):
        #Get second page and confirm it has (exactly) remaining 3 items
        resp = self.client.get(reverse('authors')+'?page=2')
        self.assertEqual(resp.status_code, 200)
        self.assertTrue('is_paginated' in resp.context)
        self.assertTrue(resp.context['is_paginated'] == True)
        self.assertTrue( len(resp.context['author_list']) == 3)

在test_view.py裡面也可以作出比較複雜的假資料，幫假資料的每個欄位都設定特定value：

#練習做出比較作出比較複雜的假資料，幫假資料的每個欄位都設定特定value
import datetime
from django.utils import timezone
        
from catalog.models import BookInstance, Book, Genre, Language
from django.contrib.auth.models import User #Required to assign User as a borrower

class LoanedBookInstancesByUserListViewTest(TestCase):

    def setUp(self):
        #Create two users
        test_user1 = User.objects.create_user(username='testuser1', password='12345') 
        test_user1.save()
        test_user2 = User.objects.create_user(username='testuser2', password='12345') 
        test_user2.save()
        
        #Create a book
        test_author = Author.objects.create(first_name='John', last_name='Smith')
        test_genre = Genre.objects.create(name='Fantasy')
        test_language = Language.objects.create(name='English')
        test_book = Book.objects.create(title='Book Title', summary = 'My book summary', isbn='ABCDEFG', author=test_author, language=test_language)
        # Create genre as a post-step
        genre_objects_for_book = Genre.objects.all()
        test_book.genre.set(genre_objects_for_book) #Direct assignment of many-to-many types not allowed.
        test_book.save()

        #Create 30 BookInstance objects
        number_of_book_copies = 30
        for book_copy in range(number_of_book_copies):
            return_date= timezone.now() + datetime.timedelta(days=book_copy%5)
            if book_copy % 2:
                the_borrower=test_user1
            else:
                the_borrower=test_user2
            status='m'
            BookInstance.objects.create(book=test_book,imprint='Unlikely Imprint, 2016', due_back=return_date, borrower=the_borrower, status=status)
        
    def test_redirect_if_not_logged_in(self):
        resp = self.client.get(reverse('my-borrowed'))
        self.assertRedirects(resp, '/accounts/login/?next=/catalog/mybooks/')

    def test_logged_in_uses_correct_template(self):
        login = self.client.login(username='testuser1', password='12345')
        resp = self.client.get(reverse('my-borrowed'))
        
        #Check our user is logged in
        self.assertEqual(str(resp.context['user']), 'testuser1')
        #Check that we got a response "success"
        self.assertEqual(resp.status_code, 200)

        #Check we used correct template
        self.assertTemplateUsed(resp, 'catalog/bookinstance_list_borrowed_user.html')        

在test_view.py裡面也可以針對權限做測試：

#測試 有權限的使用者 才能夠 編輯BookInstance資料
from django.contrib.auth.models import Permission # Required to grant the permission needed to set a book as returned.

class RenewBookInstancesViewTest(TestCase):

    def setUp(self):
        #Create a user
        test_user1 = User.objects.create_user(username='testuser1', password='12345')
        test_user1.save()

		#testuser2將會有權限編輯BookInstance的權限
        test_user2 = User.objects.create_user(username='testuser2', password='12345')
        test_user2.save()
        
        
        permission = Permission.objects.get(codename='can_view_all_borrowed_books')              
        #這樣寫也可以
        # permission = Permission.objects.get(name='one can view all borrowed books')   
        test_user2.user_permissions.add(permission)
        test_user2.save()

        #Create a book
        test_author = Author.objects.create(first_name='John', last_name='Smith')
        test_genre = Genre.objects.create(name='Fantasy')
        test_language = Language.objects.create(name='English')
        test_book = Book.objects.create(title='Book Title', summary = 'My book summary', isbn='ABCDEFG', author=test_author, language=test_language,)
        # Create genre as a post-step
        genre_objects_for_book = Genre.objects.all()
        test_book.genre.set(genre_objects_for_book) # Direct assignment of many-to-many types not allowed.
        test_book.save()

        #Create a BookInstance object for test_user1
        return_date= datetime.date.today() + datetime.timedelta(days=5)
        self.test_bookinstance1=BookInstance.objects.create(book=test_book,imprint='Unlikely Imprint, 2016', due_back=return_date, borrower=test_user1, status='o')

        #Create a BookInstance object for test_user2
		#testuser2才有權限編輯他借的這本BookInstance
        return_date= datetime.date.today() + datetime.timedelta(days=5)
        self.test_bookinstance2=BookInstance.objects.create(book=test_book,imprint='Unlikely Imprint, 2016', due_back=return_date, borrower=test_user2, status='o')

    def test_redirect_if_not_logged_in(self):
        resp = self.client.get(reverse('renew-book-librarian', kwargs={'pk':self.test_bookinstance1.pk,}) )
        #Manually check redirect (Can't use assertRedirect, because the redirect URL is unpredictable)
        self.assertEqual( resp.status_code,302)
        self.assertTrue( resp.url.startswith('/accounts/login/') )
        
    def test_redirect_if_logged_in_but_not_correct_permission(self):
        login = self.client.login(username='testuser1', password='12345')
        resp = self.client.get(reverse('renew-book-librarian', kwargs={'pk':self.test_bookinstance1.pk,}) )
        
        #Manually check redirect (Can't use assertRedirect, because the redirect URL is unpredictable)
        self.assertEqual( resp.status_code,302)
        self.assertTrue( resp.url.startswith('/accounts/login/') )

    def test_logged_in_with_permission_borrowed_book(self):
        login = self.client.login(username='testuser2', password='12345')
        resp = self.client.get(reverse('renew-book-librarian', kwargs={'pk':self.test_bookinstance2.pk,}) )
        
        #Check that it lets us login - this is our book and we have the right permissions.
        self.assertEqual( resp.status_code,200)

    def test_logged_in_with_permission_another_users_borrowed_book(self):
        login = self.client.login(username='testuser2', password='12345')
        resp = self.client.get(reverse('renew-book-librarian', kwargs={'pk':self.test_bookinstance1.pk,}) )
        
        #Check that it lets us login. We're a librarian, so we can view any users book
        self.assertEqual( resp.status_code,200)

    def test_HTTP404_for_invalid_book_if_logged_in(self):
        import uuid 
        test_uid = uuid.uuid4() #unlikely UID to match our bookinstance!        
        login = self.client.login(username='testuser2', password='12345')                
        resp = self.client.get(reverse('renew-book-librarian', kwargs={'pk':test_uid,}) )
        # print('resp.status_code:' + str(resp.status_code))
        # print('resp.url:' + str(resp.url))                
        self.assertEqual( resp.status_code,404)
        
    def test_uses_correct_template(self):
        login = self.client.login(username='testuser2', password='12345')
        resp = self.client.get(reverse('renew-book-librarian', kwargs={'pk':self.test_bookinstance1.pk,}) )
        self.assertEqual( resp.status_code,200)

        #Check we used correct template
        self.assertTemplateUsed(resp, 'catalog/book_renew_librarian.html')                

    def test_form_renewal_date_initially_has_date_three_weeks_in_future(self):
        login = self.client.login(username='testuser2', password='12345')
        #test_bookinstance1竟然可以直接代表該資料表的第一個物件FirstOrDefault()，好神！
        resp = self.client.get(reverse('renew-book-librarian', kwargs={'pk':self.test_bookinstance1.pk,}) )
        self.assertEqual( resp.status_code,200)
        
        date_3_weeks_in_future = datetime.date.today() + datetime.timedelta(weeks=3)
        #resp.context['form'].initial['renewal_date']用來取得form上面的物件value
        self.assertEqual(resp.context['form'].initial['renewal_date'], date_3_weeks_in_future )        

    def test_redirects_to_all_borrowed_book_list_on_success(self):
        login = self.client.login(username='testuser2', password='12345')
        valid_date_in_future = datetime.date.today() + datetime.timedelta(weeks=2)
        resp = self.client.post(reverse('renew-book-librarian', kwargs={'pk':self.test_bookinstance1.pk,}), {'renewal_date':valid_date_in_future} )
        self.assertRedirects(resp, reverse('all-borrowed') )        

    def test_form_invalid_renewal_date_past(self):
        login = self.client.login(username='testuser2', password='12345')       
        date_in_past = datetime.date.today() - datetime.timedelta(weeks=1)
        resp = self.client.post(reverse('renew-book-librarian', kwargs={'pk':self.test_bookinstance1.pk,}), {'renewal_date':date_in_past} )
        self.assertEqual( resp.status_code,200)
        #assertFormError表示此測試必定會發生錯誤
        self.assertFormError(resp, 'form', 'renewal_date', 'Invalid date - renewal in past')
        
    def test_form_invalid_renewal_date_future(self):
        login = self.client.login(username='testuser2', password='12345')
        invalid_date_in_future = datetime.date.today() + datetime.timedelta(weeks=5)
        resp = self.client.post(reverse('renew-book-librarian', kwargs={'pk':self.test_bookinstance1.pk,}), {'renewal_date':invalid_date_in_future} )
        self.assertEqual( resp.status_code,200)
        self.assertFormError(resp, 'form', 'renewal_date', 'Invalid date - renewal more than 4 weeks ahead')        

個人見解本篇最重要的一點：
在每個系統功能完成的時候，利用python內建的test framework或是selenium來做自動化的測試最大的好處就是，當以後新增或是修改大量的系統功能之後，工程師只要輕鬆的按下"開始測試"的按鍵，然後回家睡覺，明天一大早就可以知道最近的修改是否影響到系統的正常運作！不用在那邊手動測試老半天！！
然後隔天沒問題的話就可以把最新版的程式碼發行上去了！


參考資料：
Django Tutorial Part 10: Testing a Django web application
https://developer.mozilla.org/en-US/docs/Learn/Server-side/Django/Testing