Types of Testing : What are Different Software Testing Types?

As engineers, the end-goal is to build high-quality software. Testing plays a vital role in achieving this goal. But with so many different types of testing, it can be overwhelming to understand which one to use and when. This blog post aims to be your one-stop guide to the various software testing types, empowering you to make informed decisions and ensure our applications are robust and user-friendly.

Broadening Our Testing Horizons

Traditionally, testing might have been viewed as a separate phase after development. However, modern software development methodologies like Agile emphasize continuous integration and continuous delivery (CI/CD). This means testing is integrated throughout the development lifecycle, not just at the end.

Here's a high-level categorization of testing types to get started:

• Functional Testing: Verifies if the software fulfills its intended functionalities as per requirements.

• Non-Functional Testing: Evaluates characteristics like performance, usability, and security.

Let's delve deeper into these categories and explore specific testing types within them.

Functional Testing: Ensuring Features Work as Expected

Functional testing focuses on the "what" of the application. Here are some common types:

• Unit Testing: The foundation of functional testing. Individual software units (functions, classes) are tested in isolation.

  
  

def add_numbers(x, y):
  """Adds two numbers and returns the sum."""

  return x + y

# Unit test example (using Python's unittest framework)

import unittest

class TestAddNumbers(unittest.TestCase):

  def test_positive_numbers(self):

    result = add_numbers(2, 3)

    self.assertEqual(result, 5)

  def test_negative_numbers(self):

    result = add_numbers(-2, -5)

  # ... and so on for various test cases

• Integration Testing: Focuses on how different units interact and work together.

Example:

Imagine you're building an e-commerce application. Now integration testing would ensure the add_to_cart function properly interacts with the shopping cart database and updates the product inventory.

Action:  

Develop integration tests that simulate how different modules of your application communicate with each other. Tools like Mockito (Java) or HyperTest can be used to mock external dependencies during integration testing.

• End-to-End Testing: 

  Simulates real user scenarios and tests the entire software flow from start to finish.

Example:  

An end-to-end test for the e-commerce application could involve a user adding a product to the cart, proceeding to checkout, entering payment information, and receiving an order confirmation.

Action: 

Utilize tools like Selenium or Cypress to automate end-to-end tests. These tools allow you to record user interactions and playback those recordings to test various scenarios.

💡 Test your application’s end-to-end with integration tests, without the need to keep all your services up and running. Learn it here.

• Regression Testing: Re-runs previously passed tests after code changes to ensure new features haven't broken existing functionality.

Action:

Integrate regression testing into your CI/CD pipeline. This ensures that every code change triggers a suite of regression tests, catching bugs early on.

Let's look at a real-world example

A social media platform might use a combination of functional testing types. Unit tests would ensure individual functionalities like creating a post or sending a message work correctly. Integration tests would verify how these features interact, for example, ensuring a new message triggers a notification for the recipient. Finally, end-to-end tests would simulate user journeys like creating a profile, following other users, and engaging in content.

+--------------------+      +--------------------+      +--------------------+      +--------------------+
| Start Testing       | ---- | Unit Testing       | ---- | Integration Testing | ---- | End-to-End Testing  |

+--------------------+      +--------------------+      +--------------------+      +--------------------+

          |                          |                          |                          |

          V                          V                          V                          V

+--------------------+      +--------------------+      +--------------------+      +--------------------+

| Individual        | ---- | Create Post,        | ---- | Feature             | ---- | User Journeys       |

| Functionalities   |      | Send Message        |      | Interactions        |      | (Create Profile,    |

+--------------------+      +--------------------+      +--------------------+      +--------------------+

          | (Success?)             | (Success?)             | (Success?)             |

          V                          V                          V                          V

+--------------------+      +--------------------+      +--------------------+      +--------------------+

| Fix Bugs           | ---- |                      | ---- | Fix Bugs            | ---- | Fix Bugs            |

+--------------------+      +--------------------+      +--------------------+      +--------------------+

          |                          |                          |                          |

          ^                          ^                          ^                          ^

+--------------------+      +--------------------+      +--------------------+      +--------------------+

|                      | ---- | New Message ->       | ---- |                      | ---- | Create Profile,     |

|                      |      | Notification         |      |                      |      | Follow Users,       |

+--------------------+      +--------------------+      +--------------------+      +--------------------+

                                 |                          |                          |

                                 V                          V                          V

+--------------------+      +--------------------+      +--------------------+

|                      | ---- | Deployment           |      |                      |

+--------------------+      +--------------------+      +--------------------+