Off-by-one diagnostic

[mattmassicotte]

After a little digging, I've discovered that the following document will produce a diagnostic with a position that is 1 character past the end of the last line. Something with the line being empty matters here. If it is a single space, things are ok.

require 'a thing'

class Example
  # @return [String]
  def stringify
    "example".
  end
end

Example.new.stringify(1, 2)
Example.new.stringify(1, 2)

The diagnostic is:

unexpected token $end
(Using Ruby 2.5 parser; configure using `TargetRubyVersion` parameter, under `AllCops`)

rubocop.yml

Style/StringLiterals:
  EnforcedStyle: double_quotes

[castwide]

That diagnostic gets reported because of the trailing period in "example".. Solargraph can ignore those kinds of syntax errors under certain circumstances, but RuboCop still detects it.

[mattmassicotte]

Just to be really clear, the diagnostic itself is expected. The range it returns is out of bounds.

[castwide]

Ah, gotcha. RuboCop uses 1-based lines and columns, and there's a branch in the reporter that doesn't account for it. I'll fix it in a patch.

[castwide]

Released in v0.47.2.