Programming Concepts Beginner

What is Unit Testing?

Testing individual components or functions of a program in isolation to verify they work correctly.

Unit tests verify that individual functions, methods, or classes produce correct output for given inputs. They run fast, test in isolation (using mocks/stubs for dependencies), and provide immediate feedback when code breaks.

Popular frameworks include pytest (Python), JUnit (Java), Jest (JavaScript), and PHPUnit (PHP). Test-Driven Development (TDD) writes tests before implementation. Good tests are independent, repeatable, and cover edge cases.

Learn More About This Topic

Mastering Python Object-Oriented Programming

Related reading

Mastering Python Object-Oriented Programming - 2nd Edition (2026)

Related reading

Clean Python Code: Best Practices for Writing Maintainable and Readable Python

Related reading

Related Terms

A data structure that maps keys to values using a hash function, providing average O(1) time complexity for lookups, insertions, and deletions.

A bug that occurs when the behavior of software depends on the timing or order of uncontrolled events like thread scheduling.

Event-Driven Architecture

A software design pattern where components communicate by producing and consuming events rather than direct method calls.

A way of organizing and storing data in a computer so it can be accessed and modified efficiently.

A data structure that follows Last-In-First-Out (LIFO) ordering, where elements are added and removed from the same end (top).

Version Control

A system that records changes to files over time, allowing you to recall specific versions, collaborate, and track history.

View All Programming Concepts Terms →