My name is Stephen and I’m a Devop working at REA with about 7 years experience writing Python.
Communication is difficult. I don’t think I’m alone in this but it’s certainly something I’ve battled with over the years. Nothing is more daunting to me than a “clear communication skills” requirement in a job posting.
I even nearly failed TEE English! My final year of highschool I got 20% in my English exam in the first semester. That was a disheartening point in time. The good news is I learnt from that failure and put in a lot of effort to actually pass (barely!) in the second semester.
The great news is form isn’t as important as intent. This is why we can have such internet phenomena as doge (much internet, so hilarious) and dolan. It’s why we can have conversations over twitter and facebook comments.
Writing a blog post is daunting, especially if there is a chance many people will read it. All kinds of insecurities rise to the surface. Especially in the face of the great internet force of grammar Nazis.
I’m not quite at the point of my own public blog (where would the content come from?!) but I have an internal company blog I write to, I started using Twitter (that’s a micro blog right?) and I’m writing this.
Step 1: Put out content
Step 2: ???
Step 3: Profit
Communication is hard, but that shouldn’t stop us.
Recently, I presented a talk at the DevOpsDays conference in Brisbane, Australia on how a team of people can utilise the best of DevOPS to deal with legacy applications. Specifically how migration, ownership, maintenance and handover of legacy applications can be handled.
The below video is a tale of such a journey that my team undertook recently.
Please don’t use mocks or stubs in tests. While they are seemingly ubiquitous in enterprise development, they have serious drawbacks, and typically mask easily fixable deficiencies in the underlying code.
Even their most ardent defenders concede that mocks and stubs have flaws. These include:
Dependence on fragile implementation details
Mocks and stubs require intimate knowledge of how code interacts with other modules. Even if the implementation is correctly refactored without altering public contracts, these tests will tend to break, and draw your attention away from more productive tasks.
Testing incidental properties with no bearing on correctness
What is the point of this code? This is an essential question to ask, in order to understand it. Tests have a story to tell here, and mocks invariably tell the wrong one. Is the point of makeCoffee() that we made a coffee, or that we opened the fridge to get the milk? When we payShopkeeper(), do we care that we completed a transaction, or that we rummaged though our wallet for change? When mocking tests fail, the poor maintainer is left to reconstruct the real intent from a trail of indirect clues and anecdotes.
Web of lies
It is good practice to write data structures that are correct-by-construction; any constructor or sequence of method calls is guaranteed to leave the data in a meaningful state. Stubs introduce test-only fictions that are stripped of any of the safety latches and guarantees that may have been built in; they introduce fresh sources of error that are not present in the codebase. There is no value in detecting any failure that arises in such a way.
As time goes on, lies beget more lies. It is not unusual for a stubbed input in one place to result in another here, and another there; the fiction leaks and spreads into some kind of evil facsimile of the original code, but with more bulk, complexity and defects.
Hack Day at REA is something that started very small in IT 4 years ago and has grown to become the showpiece of culture, collaboration and innovation for the whole company. It took us a while to get there but we’ve cracked the formula for awesome Hack Days and now have an ever growing roster of visitors coming to see how we do it. We put together a little video that showcases our Hack Day story. We hope you enjoy it and it sparks some ideas on how to do it in your own company. Share your own Hack Day story in the comments below!