'Convert to raw string without leading whitespace' erroneously strips trailing whitespace

[jnm2]

Version Used: 17.3.0-p2.0

This is not the semantics change described by the light bulb fix.

var whereClause = "Age >= 18";

var x = @"
    select FirstName, LastName
    from dbo.People
    where " + whereClause;

💡 "Convert to raw string without leading whitespace (may change semantics)":

var whereClause = "Age >= 18";

var x = """
    select FirstName, LastName
    from dbo.People
    where
    """ + whereClause;

The resulting string contains whereAge >= 18 instead of where Age >= 18.

[AraHaan]

I think this behavior is what the feature was intended to do. I would say that whereClause should prefix itself with the space that is lost (or have it check for the space prefix and if not there insert it to be first).

[CyrusNajmabadi]

I did write this:

            // Remove all trailing whitespace and newlines from the final string.
            while (result.Count > 0 && (IsCSharpNewLine(result[^1]) || IsCSharpWhitespace(result[^1])))
                result.RemoveAt(result.Count - 1);

But i can't remember why :). I'm not opposed to removing this.

[davidwengier]

Perhaps that bit of code should only apply if the string doesn't have anything after it except a semi-colon? I quite like that:

var x = @"
class C
{
}
";

is converted to

var x = """
class C
{
}
""";

In fact I like the removal of trailing whitespace so much I logged https://github.com/dotnet/roslyn/issues/61267 (just in case you felt like fixing that at the same time 😛)

[CyrusNajmabadi]

Ah yes. That was the intent. It probably makes sense to delete whitespace and newlines up through and trailing whitespace on the last content line

[jnm2]

I would say that whereClause should prefix itself with the space that is lost (or have it check for the space prefix and if not there insert it to be first).

@AraHaan This seems like an onerous amount of overhead for something that's not really dynamic, just factored across multiple statements. Either way, it's extremely hard to notice that the trailing whitespace has changed; it's not a good pit. Leading whitespace is specifically called out in the light bulb in a way that sounds exclusive.

[jnm2]

@davidwengier @CyrusNajmabadi I don't think I like that conversion, and I really don't like the fact that we mention leading whitespace in a way that sounds like nothing else will be changed.

If we have to do any trailing trimming, could we please make this simply remove trailing \r\n or \n, once?

var x = @"
class C
{
}

";

Should not be converted to:

var x = """
class C
{
}
""";

[CyrusNajmabadi]

@jnm2 definitely. Feel free to create PR here :)