C# #if and #endif indentation is reset after formatting messing with folding of outer code

[aeschli]

From @uday0408 on February 3, 2018 1:54

• VSCode Version: 1.19.3
• OS Version: Mac OS X, 10.13
• C# Extension version: Omnisharp 1.13.1

For C#, after formatting with Omnisharp installed, the #region and #endregion statements are indented at the same level of enclosing code. But #if and #endif are formatted to have no indentation, thus messing with folding when #if/#endif enclosing code is nested.

I don't know if this is Omnisharp or VSCode problem.

Steps to Reproduce:

1. Apply formatting to following code

public static class Main
{
    public static int Foo(int x)
    {
        x = 5;
        #if false
        x++;
        #endif
        return x;
    }
}

2. After formatting it looks like this:

public static class Main
{
    public static int Foo(int x)
    {
        x = 5;
#if false
        x++;
#endif
        return x;
    }
}

3. This messes with folding of entire code!!

Does this issue occur when all extensions are disabled?: Yes/No

Copied from original issue: microsoft/vscode#42861

[aeschli]

From @alexandrudima on February 5, 2018 9:37

I believe the way Omnisharp (Roslyn) formats is the generally accepted way for formatting C# macros.

The problem is that our folding regions are currently computed in a language agnostic way, based on indentation.

[aeschli]

The request for language aware folding is microsoft/vscode#3422.

Moving to Omnisharp to decide whether the formatter needs to be changed or made configurable.

[DustinCampbell]

This is working as designed. The C# formatter (the same formatter used in Visual Studio) always places preprocessor directives in the left column. Currently, I don't believe there's an option to change this behavior.

cc @jinujoseph, @kuhlenh (and also @Pilchie) to see if this something we might want to add to Roslyn.

[uday0408]

So #region and #endregion are special case of preprocessor macros? They are not placed at the left most column, since September 2017 release.

[DustinCampbell]

Correct #region and #endregion are treated specially by the C# formatter.

[Leopotam]

@aeschli you can try this extension with "csharpfixformat.style.indent.preprocessorIgnored": false setting.

[DustinCampbell]

@uday0408, please see @Leopotam's reply above for a way to add this behavior.

[uday0408]

Using C# Fix Format extension and "csharpfixformat.style.indent.preprocessorIgnored": false setting I was able to use the #if / #endif directives without having them completely outdented. This allowed the folding to work correctly in VSCode which is what I wanted. Thanks!

[DustinCampbell]

@uday0408: FWIW, we've been asking for awhile to have an API from VS Code that languages can use to define custom folding (microsoft/vscode#3422). Once we have that, we'll be able to make folding work for #if / #endif correctly. Currently, I would suspect that the folding will not be accurate for nested #if / #endif when #else is interspersed.