Automatically indent (and de-indent on braces) in single line `if`/`for`/`while`

[dibarbet]

Copied from microsoft/vscode-dotnettools#618

Describe the Issue

After write an if/for/while and hitting enter (presumably to write an one line statement with no brackets), the caret should go to next line with a nested indentation level, not the same as if/for/while

VS/ VSMac:

Screen.Recording.2023-10-15.at.1.47.27.PM.mov

VSCode:

Screen.Recording.2023-10-15.at.1.56.32.PM.mov

I really think .NET on VSCode have potential. But this kind of paper-cut make really annoy to use it.

Steps To Reproduce

Hit Enter after an if/while/for statement

Expected Behavior

It should just behave like VS or VSMac editor

Environment Information

VSCode: Version: 1.83.1 (Universal)
Commit: f1b07bd25dfad64b0167beb15359ae573aecd2cc
Date: 2023-10-10T23:46:55.789Z (4 days ago)
Electron: 25.8.4
ElectronBuildId: 24154031
Chromium: 114.0.5735.289
Node.js: 18.15.0
V8: 11.4.183.29-electron.0
OS: Darwin x64 22.6.0

C# v2.6.24
C# Dev Kit v0.5.150

[dibarbet]

Unfortunately this is not as easy to do in VSCode as it is in VS. Indentation is defined by regex based rules and not integrated into the extension itself (for latency reasons).

While I believe it would be possible to update the grammar to recognize if (xyz) as requiring another level indention afterwards, it would break the scenario where you want to type a { instead. You'd get this instead:

if (xyz)
    {
    }

which is worse than the current behavior as you have to go manually fix up both lines.

The way this is resolved in VS is that we un-indent if we see that you type a {. However in vscode this is more complicated. We would have to make a call to the server to handle this (like on auto insert) to de-indent on {. Which is possible, but also introduces latency that doesn't happen in VS.

For now leaving in the backlog.