class RuboCop::Cop::Layout::EmptyLineBetweenDefs
Checks whether class/module/method definitions are separated by one or more empty lines.
‘NumberOfEmptyLines` can be an integer (default is 1) or an array (e.g. [1, 2]) to specify a minimum and maximum number of empty lines permitted.
‘AllowAdjacentOneLineDefs` configures whether adjacent one-line definitions are considered an offense.
@example EmptyLineBetweenMethodDefs: true (default)
# checks for empty lines between method definitions. # bad def a end def b end
@example
# good def a end def b end
@example EmptyLineBetweenClassDefs: true (default)
# checks for empty lines between class definitions. # bad class A end class B end def b end
@example
# good class A end class B end def b end
@example EmptyLineBetweenModuleDefs: true (default)
# checks for empty lines between module definitions. # bad module A end module B end def b end
@example
# good module A end module B end def b end
@example AllowAdjacentOneLineDefs: true (default)
# good class ErrorA < BaseError; end class ErrorB < BaseError; end class ErrorC < BaseError; end # good class ErrorA < BaseError; end class ErrorB < BaseError; end class ErrorC < BaseError; end
@example AllowAdjacentOneLineDefs: false
# bad class ErrorA < BaseError; end class ErrorB < BaseError; end class ErrorC < BaseError; end # good class ErrorA < BaseError; end class ErrorB < BaseError; end class ErrorC < BaseError; end
Constants
- MSG
Public Class Methods
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 114 def self.autocorrect_incompatible_with [Layout::EmptyLines] end
Public Instance Methods
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 144 def autocorrect(corrector, prev_def, node, count) # finds position of first newline end_pos = end_loc(prev_def).end_pos source_buffer = end_loc(prev_def).source_buffer newline_pos = source_buffer.source.index("\n", end_pos) # Handle the case when multiple one-liners are on the same line. newline_pos = end_pos + 1 if newline_pos > node.source_range.begin_pos if count > maximum_empty_lines autocorrect_remove_lines(corrector, newline_pos, count) else autocorrect_insert_lines(corrector, newline_pos, count) end end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 130 def check_defs(nodes) count = blank_lines_count_between(*nodes) return if line_count_allowed?(count) return if multiple_blank_lines_groups?(*nodes) return if nodes.all?(&:single_line?) && cop_config['AllowAdjacentOneLineDefs'] correction_node = nodes.last location = correction_node.loc.keyword.join(correction_node.loc.name) add_offense(location, message: message(correction_node, count: count)) do |corrector| autocorrect(corrector, *nodes, count) end end
We operate on ‘begin` nodes, instead of using `OnMethodDef`, so that we can walk over pairs of consecutive nodes and efficiently access a node’s predecessor; prev_node ends up doing a linear scan over siblings, so we don’t want to call it on each def.
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 123 def on_begin(node) node.children.each_cons(2) do |prev, n| nodes = [prev, n] check_defs(nodes) if nodes.all? { |def_candidate| candidate?(def_candidate) } end end
Private Instance Methods
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 267 def allowance_range? minimum_empty_lines != maximum_empty_lines end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 251 def autocorrect_insert_lines(corrector, newline_pos, count) difference = minimum_empty_lines - count where_to_insert = range_between(newline_pos, newline_pos + 1) corrector.insert_after(where_to_insert, "\n" * difference) end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 244 def autocorrect_remove_lines(corrector, newline_pos, count) difference = count - maximum_empty_lines range_to_remove = range_between(newline_pos, newline_pos + difference) corrector.remove(range_to_remove) end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 208 def blank_lines_count_between(first_def_node, second_def_node) lines_between_defs(first_def_node, second_def_node).count(&:blank?) end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 162 def candidate?(node) return unless node method_candidate?(node) || class_candidate?(node) || module_candidate?(node) end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 172 def class_candidate?(node) cop_config['EmptyLineBetweenClassDefs'] && node.class_type? end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 232 def def_end(node) end_loc(node).line end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 228 def def_start(node) node.loc.keyword.line end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 236 def end_loc(node) if (node.def_type? || node.defs_type?) && node.endless? node.loc.expression.end else node.loc.end end end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 186 def expected_lines if allowance_range? "#{minimum_empty_lines..maximum_empty_lines} empty lines" else lines = maximum_empty_lines == 1 ? 'line' : 'lines' "#{maximum_empty_lines} empty #{lines}" end end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 204 def line_count_allowed?(count) (minimum_empty_lines..maximum_empty_lines).cover?(count) end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 220 def lines_between_defs(first_def_node, second_def_node) begin_line_num = def_end(first_def_node) end_line_num = def_start(second_def_node) - 2 return [] if end_line_num.negative? processed_source.lines[begin_line_num..end_line_num] end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 216 def maximum_empty_lines Array(cop_config['NumberOfEmptyLines']).last end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 180 def message(node, count: nil) type = node_type(node) format(MSG, type: type, expected: expected_lines, actual: count) end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 168 def method_candidate?(node) cop_config['EmptyLineBetweenMethodDefs'] && (node.def_type? || node.defs_type?) end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 212 def minimum_empty_lines Array(cop_config['NumberOfEmptyLines']).first end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 176 def module_candidate?(node) cop_config['EmptyLineBetweenModuleDefs'] && node.module_type? end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 195 def multiple_blank_lines_groups?(first_def_node, second_def_node) lines = lines_between_defs(first_def_node, second_def_node) blank_start = lines.each_index.select { |i| lines[i].blank? }.max non_blank_end = lines.each_index.reject { |i| lines[i].blank? }.min return false if blank_start.nil? || non_blank_end.nil? blank_start > non_blank_end end
# File lib/rubocop/cop/layout/empty_line_between_defs.rb, line 258 def node_type(node) case node.type when :def, :defs :method else node.type end end