class RuboCop::Cop::Layout::SpaceBeforeBlockBraces

}
a.bar.to_s
foo.map{ |a|
# good
}
a.bar.to_s
foo.map { |a|
# bad
@example EnforcedStyle: no_space
}
a.bar.to_s
foo.map { |a|
# good
}
a.bar.to_s
foo.map{ |a|
# bad
@example EnforcedStyle: space (default)
brace depending on configuration.
Checks that block braces have or don’t have a space before the opening

def self.autocorrect_incompatible_with 

def self.autocorrect_incompatible_with
  [Style::SymbolProc]
end

def autocorrect(range) 

def autocorrect(range)
  lambda do |corrector|
    case range.source
    when /\s/ then corrector.remove(range)
    else           corrector.insert_before(range, ' ')
    end
  end
end

def check_empty(left_brace, space_plus_brace, used_style) 

def check_empty(left_brace, space_plus_brace, used_style)
  return if style_for_empty_braces == used_style
  config_to_allow_offenses['EnforcedStyleForEmptyBraces'] =
    used_style.to_s
  if style_for_empty_braces == :space
    add_offense(left_brace, location: left_brace, message: MISSING_MSG)
  else
    space = range_between(space_plus_brace.begin_pos,
                          left_brace.begin_pos)
    add_offense(space, location: space, message: DETECTED_MSG)
  end
end

def check_non_empty(left_brace, space_plus_brace, used_style) 

def check_non_empty(left_brace, space_plus_brace, used_style)
  case used_style
  when style  then correct_style_detected
  when :space then space_detected(left_brace, space_plus_brace)
  else             space_missing(left_brace)
  end
end

def empty_braces?(loc) 

def empty_braces?(loc)
  loc.begin.end_pos == loc.end.begin_pos
end

def on_block(node) 

def on_block(node)
  return if node.keywords?
  left_brace = node.loc.begin
  space_plus_brace = range_with_surrounding_space(range: left_brace)
  used_style =
    space_plus_brace.source.start_with?('{') ? :no_space : :space
  if empty_braces?(node.loc)
    check_empty(left_brace, space_plus_brace, used_style)
  else
    check_non_empty(left_brace, space_plus_brace, used_style)
  end
end

def space_detected(left_brace, space_plus_brace) 

def space_detected(left_brace, space_plus_brace)
  space = range_between(space_plus_brace.begin_pos,
                        left_brace.begin_pos)
  add_offense(space, location: space, message: DETECTED_MSG) do
    opposite_style_detected
  end
end

def space_missing(left_brace) 

def space_missing(left_brace)
  add_offense(left_brace, location: left_brace, message: MISSING_MSG) do
    opposite_style_detected
  end
end

def style_for_empty_braces 

def style_for_empty_braces
  case cop_config['EnforcedStyleForEmptyBraces']
  when 'space'    then :space
  when 'no_space' then :no_space
  when nil then style
  else raise 'Unknown EnforcedStyleForEmptyBraces selected!'
  end
end