There have only been 3 major releases with known backwards-incompatible changes. The reason you would want to test your code in so many versions of Node would be to check that you aren't depending on newer features that aren't in older versions that you want to still support.
Testing across 32 versions is probably very overkill for most people though.
(Oh, I meant to say 3 major releases since 0.10, which I arbitrarily picked as what seemed to be the earliest version still in any significant use today.)
They're not strictly backward incompatible: one should ideally only have to test across the major versions (nodejs is currently on major version 5, though that's not strictly reflective given the fork to iojs, and the change in versioning system on merge back)
Testing across all 32 (or 303) versions is still going to be useful for catching bugs and quirks between minor versions (as opposed to deliberate, documented breaking API changes)
actually for the sake of correctness, you should also test version 4 which is lts (if you are a library author) (https://github.com/nodejs/LTS)
I mean v0.10 and v0.12 are also LTS but I doubt that if you have a bigger library that its nearly impossible to support all four
>Are all these 32 actually backwards-incompatible?
Node uses semantic versioning [0] and the current release is 5.10.z
The breaking changes can be found here [1] By searching for `SEMVER-MAJOR`. Some seem rather unavoidable for progress (updating dependencies...) and some are for things that have been deprecated. I'm not an expert but it looks like there are several security related changes as well?
In my eyes a backwards incompatible change that breaks a feature that has been deprecated for years or is insecure is a change worth making. Stability is bad if it means remaining insecure.
If you fix a bug that I'm relying on for the correct behavior of my code then it's not strictly backwards compatible.
These versions include a lot of minor and patch releases. Chances are most code will run just fine on most of these versions, but if you can automate testing them all then why not do it?
That is absolutely true, 32 versions is not all versions of node, but it's the number of tags from the mhart/alpine-node[1] docker images that autochecker is using for the testing.
Semantic versioning -- basically each version here is x.y.z for some x, y, z. Node patch releases (.z) happen reasonably fast and constitute a "version of node" as used here.
Even though Node isn't a framework (it's a cross-platform, runtime environment), it is used a base for application development. However, over time, things are changed and improved, but that breaks some of the API functionality upon which some existing applications are already built around. Since these applications still run fine with a previous version, they are not likely to be constantly updated to work with later versions. Therefore, previous versions are still offered to maintain compatibility with applications that have already been developed. However, if you're starting work on a new Node application, then you are better off using the latest version.
I'm more intereted in why would you need to test against 32 versions of node.js? Doesn't it maintain backwards compatibility? Shouldn't testing against one version cover it?
I would think the more fundamental question is -- are these 32 (or 303) different versions so non-backward-compatible that the need to test on all of them is just an accepted thing out in Node.js-land? That everyone just kind of shrugs and puts up with (the way MS Windows used to crash on a near daily-basis for nearly everyone, not too many years ago)?
I know that other languages also have issues in this regard -- but for more mature languages it seems to be more an exception than than the rule (restricted to certain platforms of subsystems, say).
