Formatter requires two passes in the presence of directives inside lambda block bodies, inside argument lists

[davidwengier]

Given the following code:

namespace N
{
    public class C
    {
        protected void Render()
        {
            if (true)
            {
                    M(() =>
                        {
#nullable enable
                               if (true)
                                    {
                                    }
                                }
                        );
                }
        }
    }
}

Formatting the document once results in:

namespace N
{
    public class C
    {
        protected void Render()
        {
            if (true)
            {
                M(() =>
                    {
#nullable enable
                            if (true)
                        {
                        }
                    }
                    );
            }
        }
    }
}

Note the position of the if (true). It has been moved by the formatter, but not by enough.

Foratting the document again results in:

namespace N
{
    public class C
    {
        protected void Render()
        {
            if (true)
            {
                M(() =>
                    {
#nullable enable
                        if (true)
                        {
                        }
                    }
                    );
            }
        }
    }
}

This is now properly formatted, and subsequent formatting does nothing, as you would expect.

Removing the #nullable enable from the file fixes the issue, and the formatter does the right thing on the first pass. Alternatively, changing the code so the lambda is assigned to a discard rather than passing it as an argument, also fixes the issue, even if the #nullable enable is left in place.

This bug is the cause of dotnet/razor#5676 in Razor, which generates code in a similar form to the example here.

[jinujoseph]

Triage notes : Important for razor scenarios

[davidwengier]

Another repro in Razor: dotnet/razor#5693

[davidwengier]

This has been reported in the following VS feedback issues too:

developercommunity.visualstudio.com/t/Blazor-format-document---Formatting-goes/1560559
developercommunity.visualstudio.com/t/Blazor-Format-Document-doesnt-work-as-e/1575423
developercommunity.visualstudio.com/t/Poor-HTML-alignment-with-Blazor-componen/1660959
developercommunity.visualstudio.com/t/CtrlKD-does-not-work-for-blazor-InputS/1665709