What is test-driven development in Python?

Introduction

Test-driven development (TDD) refers to developing test cases before writing the actual code. This technique proves very efficient and is a precursor to the agile development. It focuses heavily on efficient coordination between developers and testers.

TDD is the backbone of the clean architecture, a coding convention that makes industrial quality code.

Steps for TDD

There are three major steps for TDD, and they are as follows:

• Write test: To the best of our ability, we create pinpoint unit tests.
• Code correction: If the test fails, we need to make necessary minimalistic changes to the code in correcting it.
• Refactoring: This essentially means that if the test passes, optimize the code such that the performance enhances, but the external behaviour remains unchanged.

Levels of TDD

There are two levels of TDD:

• ATDD
• DTDD

Acceptance test-driven development(ATDD) comprises only one acceptance test. This test is responsible for justifying the behavior of TDD.

Developer test-driven development(DTDD) is primarily composed of only one developer test. This singular test is responsible for providing details about the TDD.

Benefits of TDD

Some of the reasons why TDD is regarded highly is because of the following:

• End code is the optimized version and has industrial tenacity.
• Developers and testers can benefit from this coding practice throughout the development cycle.
• For applications with zero-error tolerance, TDD proves the only way forward.
• Error, test, and solution repository is maintained throughout, ensuring flexibility and reliability.

TDD supported framework

Some of the frameworks of TDD are as follows:

• JUnit
• PyUnit
• DocTest
• NUnit
• TestNG

Note: TDD follows the layered architecture and is used in clean architecture.

The following is how the project structure looks under TDD and clean architecture.

|____Educative_calculator
|    |____ __init__.py
|    |____ addition.py
|    |____ multiplication.py
|____tests
     |____ __init__.py
     |____ pytest.py
     |____ test_addition
     |     |____ __init__.py
     |     |____ new_add.py
     |____ test.multiplication
           |____ __init__.py
           |____ new_mul.py