Not quite two years ago, I put up a quick post entitled “The Iron Law of Tools”, which in its essence was: “that which does for you, can do to you” (whence comes the #4U2U in the title of this post). That particular post focused on ORMs (Entity Framework to be specific), but the warning equally applies to libraries and frameworks for other technical issues as well as process, methodology and techniques.
Libraries, frameworks, and processes (“tools” from this point forward) can make things easier by allowing you to concentrate on what to do rather than how to do it (via high-level abstractions and/or conventions). However, tools are not a substitute for understanding. Neither the Law of Unintended Consequences nor Murphy’s Law have been repealed. Without an adequate understanding of how something works, you cannot assess the costs of the trade-offs that are being made (and there are trade-offs involved, you can rely on that). Understanding is likewise necessary to recognize and fix those situations where the tool causes more problems than it solves. As Pawel Brodzinski observed in his post “A Fool With a Tool Is Still a Fool”:
Any time a discussion goes toward tools, any tools really, it’s a good idea to challenge the understanding of a tool itself and principles behind its successes. Without that shared success stories bear little value in other contexts, thus end result of applying the same tools will frequently result in yet another case of a cargo cult. While it may be good for training and consulting businesses (aka prophets) it won’t help to improve our organizations.
A fool with a tool will remain a fool, only more dangerous since now they’re armed.
Pawel’s point regarding cargo cults is particularly important. Lack of understanding of how a particular effect proceeds from a given cause often manifests as dogmatic assertions in defense of some “universal truth”. The closest thing I’ve found to a universal truth of software development is that it’s very unlikely that anything is universally applicable to every context.
It’s dangerous to conflate adherence to a tool with one’s core values, such that anyone who disagrees is “wrong” or “deluded” or “unprofessional”. That being said, values can provide a frame of reference in understanding someone’s position in regard to a tool. In “The TDD Divide: Everyone is Right”, Cory House addresses the current dispute over Test-Driven Development and notes (rightly, in my opinion):
The world is a messy place. Deadlines loom, team skills vary widely, and the impact of bugs varies greatly by industry. Ultimately, we write software to make money and solve problems. Tests are a tool that help us do both. Consider the context to determine which testing style fits for your project.
Uncle Bob is right. Quality matters. Separation of concerns and unit testing help assure the utmost quality, speed, and flexibility.
DHH is right. Sometimes the cost of unit tests exceed their benefit. Some of the benefit of automated testing can be achieved through automated integration testing instead.
You need to understand what a tool offers and what it costs and the result of that equation in relation to what’s important in your context. With that understanding, you can make a rational choice.