Should functions be entirely foldable instead of just argument/body lists?

[pieterjanvc]

System details:

Positron and OS details:

Positron Version: 2025.05.0 (system setup) build 142
Code - OSS Version: 1.99.0
Commit: 17df8dd
Date: 2025-05-05T15:59:18.321Z
Electron: 34.3.2
Chromium: 132.0.6834.210
Node.js: 20.18.3
V8: 13.2.152.41-electron.0
OS: Windows_NT x64 10.0.19045

Interpreter details:

R 4.4.2

Describe the issue:

When formatted functions with many arguments exceed the desired page width, arguments are aligned below each other (see function3 below) by styler. However, when you then try to collapse these functions to hide their body in the editor (using the downward arrow next to the line number), only the argument section collapses and not the body. This does not happen when the arguments fit on a single line, in that case the collapse is correct.

Steps to reproduce the issue:

Copy paste the following functions into an R script in Positron, then collapse each function to hide its body.

function1 <- function(functionArgument1) {
  print("Does collapse in Positron")
}

function2 <- function(
  functionArgument1
) {
  print("Does NOT collapse in Positron")
}

function3 <- function(
  functionArgument1,
  functionArgument2 = 5,
  functionArgument3 = NULL
) {
  print("Does NOT collapse in Positron")
}

Expected or desired behavior:

All functions should hide their body when collapsed, irrespective of the formatting.

Were there any error messages in the UI, Output panel, or Developer Tools console?

No

[juliasilge]

Thank you for this report! 🙌

Related to #18 and maybe possibly posit-dev/ark#815

The current behavior is that there are two folding ranges here, one for the () and one for the {}:

I have not dug deeply into this, but my current hypothesis is that this is some kind of default folding provided by VS Code itself. I believe (???) the only folding rules we provide for R right now are these for these special "region" comments:

positron/extensions/positron-r/language-configuration/r-language-configuration.json

Lines 29 to 33 in 7ad8241

	"folding": {
	"markers": {
	"start": "^\\s*#\\s*region\\b",
	"end": "^\\s*#\\s*endregion\\b"
	}

[juliasilge]

I think I'm right about where this is coming from:

If no folding range provider is available for the given language or if the user has set editor.foldingStrategy to indentation, indentation-based folding is used. A folding region starts when a line has a smaller indent than one or more following lines, and ends when there is a line with the same or smaller indent. Empty lines are ignored.

[pieterjanvc]

Thanks for looking into this!

It's not urgent but it would be nice if the language server can dictate better folding for this in future

[lionel-]

@juliasilge You're right, this is the indentation-based folding! Look where the arrow appears if you remove the indentation:

I can't reproduce what @pieterjanvc is seeing either. I see two sets of foldings, one for argument lists and the other for the { list, both induced from indentation.

[pieterjanvc]

@lionel- I actually do see the the two sets of folding and can indeed fold the body separately (the arrows just hide when not hovering the line number bar). I just find the behaviour not very intuitive given collapsing a function should ideally collapse everything (arguments + body) and not have this dictated simply by the formatting.

However, if you think this is the way folding should behave, I can accept that and just try to think about it differently.

[lionel-]

@pieterjanvc Should be fixed by #7976. Could you please try https://github.com/posit-dev/positron/releases/tag/2025.07.0-74 and let us know if that works better for you?

[pieterjanvc]

Hello,

I installed the recommended version

Positron Version: 2025.07.0 (system setup) build 74
Code - OSS Version: 1.100.0
Commit: fe621e8
Date: 2025-06-09T03:58:07.136Z
Electron: 34.5.1
Chromium: 132.0.6834.210
Node.js: 20.19.0
V8: 13.2.152.41-electron.0
OS: Windows_NT x64 10.0.19045

However, I do not see any changes when it comes to folding, with function and body folding still separated for functions that have multi-line arguments

Note the separate folding arrows for function and body for function2 and function3

Thank you for looking into this though, I appreciate it. However, I do understand if this is not a priority and I'm starting to get used to folding the body separately for my functions so don't worry if this is put on the back burner.