UseExplicitType: var in deconstruction is rewritten with unexpected newlines

[jcouv]

A number of undesirable newlines get added to the generated code during formatting.

As far as I can tell the root cause of the newlines getting added is AbstractTriviaFormatter.GetLineColumnOfWhitespace which returns a value with lines=1. This causes AbstractTriviaFormatter.AddWhitespaceTextChange to add a newline.

        [WpfFact, Trait(Traits.Feature, Traits.Features.CodeActionsUseExplicitType)]
        [WorkItem(23752, "https://github.com/dotnet/roslyn/issues/23752")]
        public async Task OnNestedDeconstructionVarWithTrivia()
        {
            await TestInRegularAndScriptAsync(
@"using System;
class Program
{
    void M()
    {
        /*before*/[|var|]/*after*/ (/*x1*/x/*x2*/, /*yz1*/(/*y1*/y/*y2*/, /*z1*/z/*z2*/)/*yz2*/) /*end*/ = new Program();
    }
    void Deconstruct(out int i, out Program s) { i = 1; s = null; }
}", @"using System;
class Program
{
    void M()
    {
        /*before*//*after*/ (
/*x1*/int x/*x2*/,
/*yz1*/(
/*y1*/int y/*y2*/,
/*z1*/Program z/*z2*/)/*yz2*/) /*end*/ = new Program();
    }
    void Deconstruct(out int i, out Program s) { i = 1; s = null; }
}", options: ExplicitTypeEverywhere());
        }

[jcouv]

Found a solution after all.