to_prepare not called on every development request

[sigmike]

Like in this stackoverflow question, my to_prepare block is called only once in development.
The Rails guide says it should be called before every request in development. Is the guide wrong?
I illustrated the issue here: ouvrages@8841e2a based on 3-2-stable. The output is <2> expected but was <1>

[jfirebaugh]

I suspect your test case is failing because config.cache_classes is true in tests.

[rafaelfranca]

Yes, if cache_classes is true so the to_prepare block will be called once. Could you confirm if this is causing the issue?

[carlosantoniodasilva]

@piglop any more info to help us on that? Otherwise we'll consider this closed, thanks!

[zhelee]

@carlosantoniodasilva I meet the same problem. I am in development mode, so config.cache_classes = false, I just use

config.to_prepare do
  binding.pry
end

to test whether it reloads on every request, but it only executes when I start the rails server, after that, it never executes again

[xiaods]

the guide description is wrong, the behavior is keep consistent to load once in my testing project.

[carlosantoniodasilva]

It's not that the guide description is wrong, it does reload on every request in development, but it's tied to the classes reloader: if you don't change anything that's reloadable, ie a model, controller, view, route, or similar, it won't be triggered. If you do change anything under app/, or your routes, then to_prepare will be called for every request that happens to have a change - or every request that needs to reload code.

I have to check with @josevalim and see if and how we're going to change the docs, but that's how it works since 3.2.

[carlosantoniodasilva]

Also important to link the related commit: fa1d9a8. See the commit description there for more info, and note that you can set config.reload_classes_only_on_change to false to get back 3.1 behavior.

[josevalim]

Yes, we need to fix the docs. to_prepare is called every time your project is reloaded, which since Rails 3.2 means every time you change a file.

[arturopie]

Was the documentation fixed? I think it still has the error.

[jpowell]

Bump - this is still incorrect in Rails docs... yeeeeeears later

[simi]

@y-yagi any reason why your fix (y-yagi@5fb9cf1) wasn't merged?

[y-yagi]

Hmm. Sorry, I couldn't remember why I didn't create a PR. If anyone interested to improve a doc, feel free to create a PR.