Why we shift testing left: A software dev cycle that doesn’t scale
thenewstack.io
thenewstack.io
"there was often a way to run the whole system, or a facsimile, on your laptop with minimal friction"
Any time the code you're developing can't be run without some special magic computer (that you don't have right now), special magic database (that isn't available right now), special magic workload (production load, yeah...), I predict the outcome is going to be crappy one way or another.
- https://thenewstack.io/improve-developer-velocity-by-decentr...
most large cloud/distributed systems cannot be realistically reproduced in your compose/k3s/whatever environment
a large cloud/distributed system must be tested on something similar in scale
at best, ROAC lets you do some development remotely/offline, but is not a reliable model of reality
I'd love to have a confirmation from someone at Meta.
edit: found an amazing discussion about their release process here: https://news.ycombinator.com/item?id=30899362
(ROAC in our case means Runs on any Kubernetes)
There are too many people navel gazing, and finding traces of ancient astronauts in the lint that they pick up.
What do you mean by this? They are finding meaning in nothing?
I miss the days when "run all the things" was F5, where the steps leading up to that point surmounted to git clone and a pair of RSA keys.
I haven't heard of this. I thought shifting left was the new hotness. I was under the impression that finding and fix mistakes as soon as possible is considered best practice.
> Shifting Testing Left Is a Return of an Older, Better System
I don't really understand. I thought the "old way" was to wait until everything was done to check if it works, and the "new way" was to add tests for individual components as you go, making sure nothing breaks as new features are added.
Hanlon's Razor would tend to discredit (b) but I've seen it in action too many times to fully accept this...
>>I thought the "old way" was to wait until everything was done to check if it works, and the "new way" was to add tests for individual components as you go, making sure nothing breaks as new features are added.
30 years ago, we did unit tests where we continually test individual components, then system tests were you test if your system works as a whole, then integration tests where you check how your system works with others. We had dedicated environments for these. And this was in the big-corporation, bog-standard, boring, commercial-off-the-shelf standard enterprise resource planning software. Yes, we had waterfall / predictive project management model, but I'm not sure where this notion comes in that before right now, this exciting brilliant moment in time, nobody in IT knew at all what they were doing and built entire bridges for years and waited to see if they'd collapse when the first car came :-)
Grumble grumble get off my lawn young kids etc etc :->
I think he was right. Today, apparently, he would be left.
There's always a context contingent cost/benefit trade off, but sometimes converting integration to unit tests is a win.
Easier context switching, less dealing with extra added complexity between coding the issue and fixing it etc.
I'm all in favour, particularly if people don't see it as an imposition!
I see this issue all the time.
The question is when to test.
There is benefit and tradeoff when you decide when and how to test your application. Sometimes you simply cannot test beforehand, such as when you are integrating with a live system with a cost of replicating the environment very very high due to this being a managed solution contract with a large cough IBM cough vendor. In these cases often the question is when to mock test. Then when to test. But this is still just how and when.
With a solo developer, it makes plenty of sense to write the feature then test it. Writing it may be the way to actually discover the behavior you want. With a team this can still be the case. In a larger team you can pass this to QA engineers to take these rapid prototypes and find the issues with them for a different type of developer to fix bugs in.
The reverse is the same. You can discover your feature behavior by experimenting with tests until the desired behavior is asserted to be occuring through things like type validation and object patching for instrumentation, or whatever profiling or debugging tools and test suites you like.
The hard answer is there is no one answer. Just like iterative development urges us to do our best to keep up by iterating on our features, we should iterate on our tests. Do not worship coverage, use it as a tool. Do not fear testing, it's just code afterall so you can actually make a full application that is just a series of tests (experiments) that run and if everything has passed, well you just wrote the same thing as a bunch of conditional checks in your library code.
Do what works for you, your team, the project you are on and where you are at. If youre struggling add some more tests. If you have so many tests failing you dont know what to do, write some more code and string your tests together with new functions. It gives a nice way to say ok, this is the next step of my iteration. Some like to start by testing some like to finish. I do both. Whatever you do, put love into it and if thats super sturdy prod code that has no tests and will never fail because you are the safest data handler in the world with the most flexible business logic in the world, go for it - but just remember if you someday later forget how things work and dont want to read documentation or experiment with the live system - you can always write tests to remind you how it works.
Tests are a form of documentation. They may not prove what you think they prove, but they document a fact about your code that is objective as determined by the code itself. This is a wonderful power, use it however you wish.
https://thenewstack.io/how-to-shift-testing-left-4-tactical-...
There really is no one answer, and you're so right that scale is one of the determining factors. Sophisticated tools like Signadot are designed to help dozens of developers use one high-accuracy shared cluster, but that makes no sense if your team is small enough to Slack 'hey I'm going to push my stuff to Staging, no one change anything' for your testing phase :)
And if all the work you're doing is well understood before you start, I suggest finding somewhere your manager you with the hard stuff.
An advocate for TDD (as in “red > green > refactor”) might say that writing the spec upfront is an excellent way to understand the problem space, or at least to help achieve that understanding.
At least when I’ve been fortunate enough to work on projects where such a TDD approach is possible, I’ve found that to be the case. I’ve also often found it harder to gain that understanding when testing lags development.
I think we overuse the term waterfall. Having a QA phase as part of a development cycle doesn't not make something "waterfall.:
If you can't risk not having QA gating your releases then your process is probably more waterfall than you might have hoped.
If you need an approval on a pull request and some automated tests to pass to give you enough confidence to deploy then that part of your process is agile at least (even if, say, the way you get requirements is not).
I've been shifting left (and using those words) for over two decades. Nothing new here.
> In this context, I think TDD is close to what it means.
Nope. It's only close in that both have to do with testing.
TDD is you writing unit tests. Shifting left is about parallelizing someone else's work in the rest of the test pyramid. If QA can write their integration/system/contract/other tests as you're writing your code, you can have working tests for new features ideally as soon as the feature is runnable/testable instead of QA waiting to "see what the dev code does" to write against it.
Like the first commenter in this thread, I’d never heard the term “shifting left” before. That’s surprising for a buzzword you say has been around for decades and is hot right now, but I guess there’s a first time for everything!