Introduction

Your app works on your machine. But does it work everywhere? Testing catches bugs before users do.

What You'll Learn

How to:

  • Write unit tests
  • Debug Flask errors
  • Use print statements effectively
  • Handle common bugs

Prerequisites

  • Flask basics
  • Part 1-5 knowledge
  • 20 minutes

Step 1: Unit Testing Basics 

import unittest class TestApp(unittest.TestCase): def test_homepage(self): response = app.test_client().get('/') self.assertEqual(response.status_code, 200)

Step 2: Test Database 

def test_create_entry(self): util.save_entry("Test", "Content") entry = util.get_entry("Test") self.assertEqual(entry, "Content")

Step 3: Debug Mode 

if __name__ == '__main__': app.run(debug=True)

Debug mode shows errors clearly and auto-reloads.

Step 4: Print Debugging 

def new_page(request): print(f"Title: {title}") # See value print(f"Content: {content}") util.save_entry(title, content)

Common Bugs

  1. Not checking if entry exists
  2. Not validating input
  3. Database connection issues

Conclusion

Testing = fewer bugs. Debug mode = faster fixes. Print statements = your best friend.

sorry friends I couldn't upload posts recently as I was working on a personal project