BRO1507: Files should not end with blank lines

A file ends with its last line of code, followed by at most one line break. Replaces StyleCop SA1518.

Example

Before

public class Order
{
    public int Id { get; set; }
}

After

public class Order
{
    public int Id { get; set; }
}

Why

Blank lines at the end of a file are invisible noise, and they show up as changes in diffs when an editor adds or trims them.

How the fix works

The fix removes everything after the last line's line break: extra blank lines, and lines containing only spaces.

Configuration

Like StyleCop's default ("newlineAtEndOfFile": "allow"), a file may end with one line break or without one. To require a final line break, use the SDK's own setting, which dotnet format applies:

[*.cs]
insert_final_newline = true

Compared with StyleCop

Same results as StyleCop's default setting. StyleCop's require and omit settings correspond to insert_final_newline = true and false in .editorconfig.