Understanding Equivalence Partitioning

1. Introduction

Welcome to this tutorial on understanding equivalence partitioning.

Tutorial's Goal

The goal of this tutorial is to guide you through the concept of Equivalence Partitioning, a software testing design technique that simplifies the testing effort.

What you will learn

By the end of this tutorial, you will have a clear understanding of:

• What equivalence partitioning is.
• Why it is important.
• How to apply it in real-world scenarios.

Prerequisites

This is a beginner-friendly tutorial. However, having some basic understanding of software testing would be helpful.

2. Step-by-Step Guide

Equivalence Partitioning is a software testing technique that divides the input data of a software unit into partitions of equivalent data from which test cases can be derived.

Explanation of Concepts

In equivalence partitioning, inputs to the software or system are divided into groups that are expected to exhibit similar behavior, hence reducing the total number of test cases to be developed.

Examples

Think of a system that accepts age as an input field. The valid age range is 18-65. Any age below 18 and above 65 is considered invalid.

Here, we can create three equivalence classes:

• Invalid equivalence class: Age < 18
• Valid equivalence class: 18 <= Age <= 65
• Invalid equivalence class: Age > 65

Best Practices and Tips

• Always remember that test cases are derived from each partition.
• Invalid partitions are also important.
• Each partition should be tested by at least one test case.

3. Code Examples

Unfortunately, equivalence partitioning is a concept used in manual testing, and thus, does not have any code examples. However, it can be used in automated testing scenarios. Here's an example in Python using pytest:

import pytest

def test_age_group():
    assert age_group(17) == 'Invalid'
    assert age_group(18) == 'Adult'
    assert age_group(65) == 'Adult'
    assert age_group(66) == 'Invalid'

In the above example, we are testing an imaginary function age_group, which should return 'Invalid' for ages below 18 and above 65, and 'Adult' for ages between 18 and 65.

4. Summary

In this tutorial, we have covered the concept of equivalence partitioning, a software testing technique that groups the input data of a software unit into partitions of equivalent data, from which test cases can be derived. We also looked at an example of how to apply this concept.

For further learning, explore boundary value analysis, which is similar to equivalence partitioning and often used together.

5. Practice Exercises

Now, let's put what we have learned into practice. Here are some exercises for you:

1. Consider a system that accepts a percentage as input. The valid range is 0-100. Create three equivalence classes for this system.
2. Consider a login system that accepts a password with a length of 6-12 characters. Create the equivalence classes for this system.

Solutions

1. For a system that accepts a percentage as input, the equivalence classes would be:

   • Invalid: Percentage < 0
   • Valid: 0 <= Percentage <= 100
   • Invalid: Percentage > 100

2. For a login system that accepts a password with a length of 6-12 characters, the equivalence classes would be:

   • Invalid: Length < 6
   • Valid: 6 <= Length <= 12
   • Invalid: Length > 12

These exercises are aimed at helping you understand how to create equivalence classes. As a tip, remember to always include both valid and invalid classes when creating your partitions.