Remove hard-coded inlay hint max length limit

[Krzysztof-Cieslak]

Discussed in #2100

^{Originally posted by nkosi23 August 22, 2025}
Vscode now has the following setting:

 "[fsharp]": {
    "editor.inlayHints.maximumLength": 0
  }

And setting it to 0 is supposed to disable truncation. However, it looks like Ionide has a hard limit at 30 characters.

This seriously degrades the usefulness of hints in my case, as my type names tend to be long, moreover i do a lot of interop with C# so it is not uncommon to have generic types like Collections.Generic.IReadOnlyList<Appointment> truncated with Collections.Generic.IReadOnlyL.

Is there a way to remove the hard limit? Otherwise, would it be possible to remove it, since vscode already takes care of it.

[baronfel]

This length limitation is being enforced by FSAC itself: https://github.com/ionide/FsAutoComplete/blob/main/src/FsAutoComplete.Core/InlayHints.fs#L79

We'd need to make FSAC aware of this setting via the existing ConfigurationChanged settings tracking and to use this length instead of our hard-coded value.

@nkosi23 are you interested in maybe trying this out?

[nkosi23]

Hey, thank you all for your swift feedback on this! Sure I'll take a look, sounds like a good first issue for a new contributor like me.

I've just taken a look at the source code, could you please give me quick pointers to the existing ConfigurationChanged settings you are mentioning? i've tried to do a quick search in the code base using variants of this symbol name but couldn't find anything like this.

[baronfel]

@nkosi23 Awesome!

So what I'm referring to here is an LSP method called workspace/didChangeConfiguration, which for us is implemented here.

Today, we only read F#-specific settings from the overall configuration Json object, but we should also be able to retrieve the value of any configuration setting we want - including editor.inlayHints.maximumLength - if it is set, because it should also be provided in this payload.

So I think we need to update our serialization to look for/understand this setting if present, and then apply that to our overall settings record that we use to represent all of the settings that the FSAC application understands. Once that setting is plumbed through, then the main InlayHints function should be able to be given the value to use, instead of using the hard-coded value.

Let me know if that is enough to get you going!

[thatrajeevkr]

is this still an issue? Can I try working on this?

[nkosi23]

Yes this is still an issue, sure you can. I've been managing personal emergencies lately so I'm not sure i'll have a chance to start working on this before the end of this week at least.