[tremon]

Irrelevant?? That is the most relevant question that a developer could ask in this situation.

No, it isn't. The most relevant question is "can somebody be using the current API". It doesn't matter if your current API matches the documentation, what matters is whether your current API is out there for others to build on.

Don't try to use a crystal ball or other form of divination to predict what your downstream users have been doing with the code; you will always lose. Instead, suck it up, acknowledge the mistake, and signal the breaking change by bumping the major version.

Maybe next time your developers will spend more time validating their public contract, so they won't have to endure the embarrassment of a major version bump.

[hluska]

Using that logic, every single bug fix that even remotely changes how the API operates would be considered a major version. What would be the point of semver?

Semver both acknowledges and is predicated upon the fact that every bug fix has a range of possible impacts. At one end, some bug fixes have almost no chance of breaking an application. At the other end, some bug fixes will almost certainly break applications.

This is not divination. It is understanding your application and its users.

Finally, in regards to your last paragraph, I genuinely hope that you don't speak to developers like that. Mistakes will always happen. Have a little bit of respect and treat people with kindness.

[Nadya]

>Using that logic, every single bug fix that even remotely changes how the API operates would be considered a major version. What would be the point of semver?

Yes. That's exactly how SemVer works. It signals to people that there was a breaking API change - it doesn't matter if you're on version 10495.0.3 - if you've somehow broken your API 10,494 times you're following SemVer. Although if you're that bad at maintaining a stable API you probably don't have any users you know... using it.

SemVer is predicated upon the fact that other people are using your API. It signals to them whether or not it should be safe to update without breaking their code that relies on your API. If you break your API - you broke their code. That makes you an asshole in their eyes. The entire point of SemVer is to signal that you broke your API so that people relying on it can examine their code for breakage, decide whether or not to update, or start working on modifying their code to match the new API.

If your API is very unstable then people aren't going to rely on it. If it's both unstable and you don't signal breaking changes I'd be amazed if anyone put up with working with it.

If I'm using version 3.0.2 I should be fine using any 3.y.z version. If you release a 4.0.0 then I know I need to investigate and determine whether or not it is safe for me to update to that version. If your API is still unstable and changing on a daily basis - you shouldn't be at 1.0.0 yet. 1.0.0 is meant to signal the "stable API stage" of development.