Chapter 15: Unit tests with Selenium (15d)

Author: miguelgrinberg

app/main/views.py

@@ -9,6 +9,17 @@
 from ..decorators import admin_required, permission_required
 
 
+@main.route('/shutdown')
+def server_shutdown():
+    if not current_app.testing:
+        abort(404)
+    shutdown = request.environ.get('werkzeug.server.shutdown')
+    if not shutdown:
+        abort(500)
+    shutdown()
+    return 'Shutting down...'
+
+
 @main.route('/', methods=['GET', 'POST'])
 def index():
     form = PostForm()

requirements/dev.txt

@@ -7,4 +7,5 @@ httpie==0.9.9
 idna==2.5
 Pygments==2.2.0
 requests==2.18.2
+selenium==3.4.3
 urllib3==1.22

tests/test_selenium.py

@@ -0,0 +1,98 @@
+import re
+import threading
+import time
+import unittest
+from selenium import webdriver
+from app import create_app, db, fake
+from app.models import Role, User, Post
+
+
+class SeleniumTestCase(unittest.TestCase):
+    client = None
+    
+    @classmethod
+    def setUpClass(cls):
+        # start Chrome
+        options = webdriver.ChromeOptions()
+        options.add_argument('headless')
+        try:
+            cls.client = webdriver.Chrome(chrome_options=options)
+        except:
+            pass
+
+        # skip these tests if the browser could not be started
+        if cls.client:
+            # create the application
+            cls.app = create_app('testing')
+            cls.app_context = cls.app.app_context()
+            cls.app_context.push()
+
+            # suppress logging to keep unittest output clean
+            import logging
+            logger = logging.getLogger('werkzeug')
+            logger.setLevel("ERROR")
+
+            # create the database and populate with some fake data
+            db.create_all()
+            Role.insert_roles()
+            fake.users(10)
+            fake.posts(10)
+
+            # add an administrator user
+            admin_role = Role.query.filter_by(name='Administrator').first()
+            admin = User(email='john@example.com',
+                         username='john', password='cat',
+                         role=admin_role, confirmed=True)
+            db.session.add(admin)
+            db.session.commit()
+
+            # start the Flask server in a thread
+            cls.server_thread = threading.Thread(target=cls.app.run,
+                                                 kwargs={'debug': False})
+            cls.server_thread.start()
+
+            # give the server a second to ensure it is up
+            time.sleep(1) 
+
+    @classmethod
+    def tearDownClass(cls):
+        if cls.client:
+            # stop the flask server and the browser
+            cls.client.get('http://localhost:5000/shutdown')
+            cls.client.quit()
+            cls.server_thread.join()
+
+            # destroy database
+            db.drop_all()
+            db.session.remove()
+
+            # remove application context
+            cls.app_context.pop()
+
+    def setUp(self):
+        if not self.client:
+            self.skipTest('Web browser not available')
+
+    def tearDown(self):
+        pass
+    
+    def test_admin_home_page(self):
+        # navigate to home page
+        self.client.get('http://localhost:5000/')
+        self.assertTrue(re.search('Hello,\s+Stranger!',
+                                  self.client.page_source))
+
+        # navigate to login page
+        self.client.find_element_by_link_text('Log In').click()
+        self.assertIn('<h1>Login</h1>', self.client.page_source)
+
+        # login
+        self.client.find_element_by_name('email').\
+            send_keys('john@example.com')
+        self.client.find_element_by_name('password').send_keys('cat')
+        self.client.find_element_by_name('submit').click()
+        self.assertTrue(re.search('Hello,\s+john!', self.client.page_source))
+
+        # navigate to the user's profile page
+        self.client.find_element_by_link_text('Profile').click()
+        self.assertIn('<h1>john</h1>', self.client.page_source)