Detect override def run: ZIO[_, _, ZIO[_, _, _]]

[jamesward]

Would it be possible to detect a run that has a ZIO which has a ZIO in the A ? I sometimes do this with ZIO Direct:

object Main extends ZIOAppDefault:
  override def run =
    defer {
      Console.printLine("hello, world")
    }

Which doesn't work because I need to actually run my printLine in the defer. Or maybe ZIO Direct should produce a warning? Not sure the right place to catch me from doing something silly.

[myazinn]

Actually, we already have an inspection that detects discarded effect (due to Unit discarding). We can expand it to trigger when ZIO effect is treated as Any, but I'm not sure if it'll cause false positives or not 🤔

[hmemcpy]

Thanks for the suggestion! I admit I haven't yet got the chance to play with zio-direct, but I know that the library ships with some IntelliJ support to help with the type inference for its macros.

Maybe @deusaquilus could elaborate on whether this is possible to detect via the defer macro. Having said this, I think it would be wise to include zio-direct support in the plugin directly.

[hmemcpy]

Ah right, I now remember why we didn't put it in the plugin - whitebox macros don't have extension points from IntelliJ plugins - they are installed and instantiated via a different mechanism. I'll have to explore whether it's possible to hack the "library extension provider"

Alex was kind enough to document it. https://zio.dev/zio-direct/intellij-support/

[hmemcpy]

(mostly a note-to-self) Lastly, I forgot about this, but @unkarjedy was able to load the extension with reflection (promising to make the method to do this public ;)). So there might be a way to hack support for this in the plugin. I'll look into it soon.

[unkarjedy]

@hmemcpy
I've just pushed a change to make it public in idea232.x, but only as @TestOnly.
You might also look at org.jetbrains.plugins.scala.components.libextensions.LibraryExtensionsManager#addExtension

[deusaquilus]

@jamesward I think ZIO-Direct should produce a warning in this situation. I'm pretty sure it does so in Metals. Need to look into what I'm doing in the ZIO-Direct IntelliJ plugin.