What’s wrong with SOLID and Test Driven Development | Coding Over Cocktails Podcast

Summary

In the 'Coding Over Cocktails' podcast, episode 67, host Kevin Montalbo engages in a thought-provoking discussion with Dan North, a prominent figure in the software development community. North challenges the SOLID principles, advocating for a new approach called CUPID, which emphasizes code properties that enhance joy and productivity in coding. The conversation delves into Behavior-Driven Development (BDD), the evolution of software design techniques, and the importance of writing simple, idiomatic, and domain-based code. North's insights reflect his extensive experience and offer a fresh perspective on software craftsmanship.

Takeaways

• 🤖 The discussion revolves around the SOLID principles in software development, introduced by Robert Martin and popularized by Michael Feathers, and their relevance in modern programming practices.
• 🔧 Daniel Terhurn, the guest, challenges the SOLID principles, suggesting that they are outdated and may not serve the current agile and flexible nature of software development.
• 🛠️ Terhurn proposes an alternative to SOLID called CUPID, which stands for Composable, Unix philosophy, Predictable, Idiomatic, and Domain-based, aiming to create joyful and easy-to-work-with code.
• 📚 SOLID principles were historically valuable but may not be as applicable in today's rapid development cycles and advanced IDEs that facilitate frequent and easy code changes.
• 🔍 The Single Responsibility Principle is critiqued for potentially leading to unnecessary complexity and separation of concerns that don't naturally align with how code changes are made.
• 🧩 The concept of 'composability' in CUPID emphasizes the importance of creating modular, interchangeable parts of code that can be easily assembled and used together.
• 📈 The 'Unix philosophy' aspect of CUPID promotes the idea of doing one thing well, suggesting that simpler, more focused functions or components can be more effective when composed.
• 🔮 'Predictability' in code refers to its behavior being easily understandable and consistent, which is more important than just having test coverage for ensuring reliable software.
• 📝 'Idiomatic' code is code that follows the common style and patterns of its language's ecosystem, making it more readable and maintainable for others in the community.
• 🏭 Domain-based coding is emphasized as important for structuring code around the business domain it serves, making it more intuitive and reducing the cognitive load for developers.
• 🌐 The interview also touches on Behavior-Driven Development (BDD), which is an evolution of Test-Driven Development (TDD), focusing on executable specifications that describe code behavior.

Q & A

What is the main topic of discussion in the 'Coding Over Cocktails' podcast episode 67?

The main topic of discussion is the SOLID principles in software development and the introduction of an alternative set of principles called CUPID, as proposed by the guest, Dan North.

Who is the founder and CEO of Toro Cloud joining the podcast from Sydney, Australia?

David Brown is the founder and CEO of Toro Cloud joining the podcast from Sydney, Australia.

What is Dan North known for in the field of software development?

Dan North is known for being the originator of Behavior-Driven Development (BDD) and for contributing to the R-Spec book, 'Behavior-Driven Development with Cucumber', and '97 Things Every Programmer Should Know'.

What does SOLID stand for in software development?

SOLID is an acronym for five design principles in object-oriented programming: Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion.

What is the main critique Dan North has against the SOLID principles?

Dan North criticizes SOLID as being outdated and not serving the current software development landscape well, considering the evolution of programming languages, tools, and practices.

What does Dan North propose as an alternative to the SOLID principles?

Dan North proposes CUPID as an alternative to SOLID, which stands for Composable, Unix Philosophy, Predictable, Idiomatic, and Domain-based.

What does the acronym CUPID represent in Dan North's alternative to SOLID principles?

CUPID represents five properties of code that Dan North believes make it joyful to work with: Composable, Unix Philosophy, Predictable, Idiomatic, and Domain-based.

What is Behavior-Driven Development (BDD) and how does it relate to Test-Driven Development (TDD)?

Behavior-Driven Development (BDD) is an approach that emerged as a response to misunderstandings in Test-Driven Development (TDD). BDD focuses on describing the behavior of the code before writing it, using executable specifications, which can also serve as tests.

What is the significance of the 'given-when-then' structure in BDD?

The 'given-when-then' structure in BDD is a template for capturing examples or scenarios that describe the behavior of the code in a clear and concise manner, making it accessible for both developers and business analysts.

How does Dan North define 'simple code' in the context of his CUPID principles?

Dan North defines 'simple code' as code that fits in someone else's head, meaning that another developer familiar with the language and domain can quickly understand the code without needing to know the tacit knowledge or context that was in the original author's head.

What is the purpose of the 'Idiomatic' property in CUPID?

The 'Idiomatic' property in CUPID emphasizes writing code in a way that is consistent with the common style and practices of the language's ecosystem, making the code more readable and maintainable for others who are familiar with that idiom.

What is the 'Domain-based' property in CUPID and why is it important?

The 'Domain-based' property in CUPID refers to structuring code around the domain it is meant to represent, using strong domain naming and organization that reflects the business domain, making the code more intuitive and reducing cognitive load for developers.

What has been the community's response to Dan North's introduction of CUPID?

The community's response to CUPID has been positive, with interest and adoption in exploring it as a set of principles for software design, although it is still not as widely recognized or adopted as SOLID.