Hey folks, shouldn't `fun Route.get(...): Route`, ...

# ktor

[evkaky]

Hey folks, shouldn't fun Route.get(...): Route, fun Route.post(...): Route and many others be annotated with @IgnorableReturnValue?
In version 3.6.0 they aren't, which seems weird to me

[simon.vergauwen]

Yes, great point! Although I've not gotten any warnings about this myself in IDEA and I have full mode enabled in a couple projects. By accident not Ktor projects? 🤔 I'm gonna double check and raise it with the team ☺️

[simon.vergauwen]

Could you share a snippet that is causing you to see a warning? I'm unsure why it's not giving me a warning though... (I'm continuing to investigate where what is needed).

[evkaky]

I don't see warning either which is also weird, as I have this in my `module.yaml`:

settings:
  ktor:
    enabled: true
    version: 3.6.0
  jvm:
    jdk:
      version: 25
  kotlin:
    freeCompilerArgs:
      - -Xreturn-value-checker=full
      - -Xwarning-level=RETURN_VALUE_NOT_USED:error

I even should see them as errors btw.
IntelliJ 2026.2.2:

[simon.vergauwen]

Okay, so at least we're seeing the same 😅 I'll let you know when I figure out why its not resulting in an error. With -Xwarning-level=RETURN_VALUE_NOT_USED:error it should indeed become an error.

[evkaky]

I didn't originally created my project as a ktor project if it matters. I just manually added ktor dependencies and put settings.ktor.enabled: true and that's all

[simon.vergauwen]

Okay, sorry I got a bit confused myself. full doesn't mean 3rd party libraries are checked but only when 3rd party libraries ship with -Xreturn-value-checker=full to signal they properly support it. Similar to platform types Java annotations are supported and can be configured.

[evkaky]

so, ktor 3.7 should be shipped with that -Xreturn-value-checker=full flag?
And with those functions (Route.get and others) annotated with @IgnorableReturnValue ?

[simon.vergauwen]

It depends 🥁 We could also add @MustUseReturnValue in places that need it or depending on module.

[evkaky]

yeah, I mean the team will put all necessary annotations (MustUseReturnValue, IgnoreableReturnValue) wherever needed to make ktor fully return-values-checker-feature compatible.
Or this is not on the table?

[simon.vergauwen]

It's absolutely on the table, and will happen asap but timeline is unclear so no guarantees on 3.7 but it should happen in timely fashion since it doesn't involve binary changes.