Class: RuboCop::Cop::Layout::LineLength

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, `::RuboCop::Cop::AutoCorrector`, `::RuboCop::Cop::Base`, `::RuboCop::ExcludeLimit`, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain: self, `::RuboCop::Cop::LineLengthHelp`, `::RuboCop::Cop::Alignment`, `::RuboCop::Cop::RangeHelp`, `::RuboCop::Cop::AllowedPattern`, `::RuboCop::Cop::CheckLineBreakable`, `::RuboCop::Cop::Base`, `::RuboCop::Cop::AutocorrectLogic`, `::RuboCop::Cop::IgnoredNode`, `::RuboCop::Util`, RuboCop::AST::Sexp
Inherits:	RuboCop::Cop::Base Object RuboCop::Cop::Base RuboCop::Cop::Layout::LineLength
Defined in:	lib/rubocop/cop/layout/line_length.rb

Overview

Checks the length of lines in the source code. The maximum length is configurable. The tab size is configured in the IndentationWidth of the Layout/IndentationStyle cop. It also ignores a shebang line by default.

This cop has some autocorrection capabilities. It can programmatically shorten certain long lines by inserting line breaks into expressions that can be safely split across lines. These include arrays, hashes, and method calls with argument lists.

If autocorrection is enabled, the following Layout cops are recommended to further format the broken lines. (Many of these are enabled by default.)

ArgumentAlignment
ArrayAlignment
BlockAlignment
BlockDelimiters
BlockEndNewline
ClosingParenthesisIndentation
FirstArgumentIndentation
FirstArrayElementIndentation
FirstHashElementIndentation
FirstParameterIndentation
HashAlignment
IndentationWidth
MultilineArrayLineBreaks
MultilineBlockLayout
MultilineHashBraceLayout
MultilineHashKeyLineBreaks
MultilineMethodArgumentLineBreaks
MultilineMethodParameterLineBreaks
ParameterAlignment

Together, these cops will pretty print hashes, arrays, method calls, etc. For example, let’s say the max columns is 25:

Examples:

# bad
{foo: "0000000000", bar: "0000000000", baz: "0000000000"}

# good
{foo: "0000000000",
bar: "0000000000", baz: "0000000000"}

# good (with recommended cops enabled)
{
  foo: "0000000000",
  bar: "0000000000",
  baz: "0000000000",
}

Constant Summary

MSG =
# File 'lib/rubocop/cop/layout/line_length.rb', line 72
```
'Line is too long. [%<length>d/%<max>d]'
```

Class Attribute Summary

`::RuboCop::Cop::AutoCorrector` - Extended

support_autocorrect?

`::RuboCop::Cop::Base` - Inherited

.gem_requirements, .lint?,
.support_autocorrect?	Returns if class supports autocorrect.
.support_multiple_source?	Override if your cop should be called repeatedly for multiple investigations Between calls to `on_new_investigation` and `on_investigation_end`, the result of `processed_source` will remain constant.
.builtin?

Class Method Summary

`::RuboCop::Cop::Base` - Inherited

.autocorrect_incompatible_with	List of cops that should not try to autocorrect at the same time as this cop.
.badge	Naming.
.callbacks_needed, .cop_name, .department,
.documentation_url	Cops (other than builtin) are encouraged to implement this.
.exclude_from_registry	Call for abstract Cop classes.
.inherited,
.joining_forces	Override and return the Force class(es) you need to join.
.match?	Returns true if the cop name or the cop namespace matches any of the given names.
.new,
.requires_gem	Register a version requirement for the given gem name.
.restrict_on_send

`::RuboCop::ExcludeLimit` - Extended

exclude_limit	Sets up a configuration option to have an exclude limit tracked.
transform

Instance Attribute Summary

#allow_heredoc? ⇒ Boolean readonly private
#breakable_range rw private

`::RuboCop::Cop::LineLengthHelp` - Included

#allow_uri?, #ignore_cop_directives?

`::RuboCop::Cop::Alignment` - Included

#column_delta

`::RuboCop::Cop::Base` - Inherited

#active_support_extensions_enabled?, #always_autocorrect?, #config, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #processed_source, #target_satisfies_all_gem_version_requirements?

`::RuboCop::Cop::AutocorrectLogic` - Included

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Instance Method Summary

#on_array(node)

Alias for #on_potential_breakable_node.
#on_block(node) (also: #on_numblock)
#on_def(node)

Alias for #on_potential_breakable_node.
#on_hash(node)

Alias for #on_potential_breakable_node.
#on_investigation_end
#on_new_investigation
#on_numblock(node)

Alias for #on_block.
#on_potential_breakable_node(node) (also: #on_array, #on_hash, #on_send, #on_def)
#on_send(node)

Alias for #on_potential_breakable_node.
#allowed_heredoc private
#allowed_line?(line, line_index) ⇒ Boolean private
#breakable_block_range(block_node) private
#breakable_range_after_semicolon(semicolon_token) private
#breakable_range_by_line_index private
#check_directive_line(line, line_index) private
#check_for_breakable_block(block_node) private
#check_for_breakable_node(node) private
#check_for_breakable_semicolons(processed_source) private
#check_line(line, line_index) private
#check_uri_line(line, line_index) private
#excess_range(uri_range, line, line_index) private
#extract_heredocs(ast) private
#heredocs private
#highlight_start(line) private
#line_in_heredoc?(line_number) ⇒ Boolean private
#line_in_permitted_heredoc?(line_number) ⇒ Boolean private
#max private
#register_offense(loc, line, line_index, length: line_length(line)) private
#shebang?(line, line_index) ⇒ Boolean private

`::RuboCop::Cop::LineLengthHelp` - Included

#allowed_uri_position?, #directive_on_source_line?, #extend_uri_end_position, #find_excessive_uri_range, #indentation_difference, #line_length, #line_length_without_directive, #match_uris, #tab_indentation_width, #uri_regexp, #valid_uri?

`::RuboCop::Cop::Alignment` - Included

#check_alignment, #configured_indentation_width, #display_column, #each_bad_alignment, #end_of_line_comment, #indentation, #offset, #register_offense, #within?

`::RuboCop::Cop::RangeHelp` - Included

#add_range, #column_offset_between,
#contents_range	A range containing only the contents of a literal with delimiters (e.g.
#directions,
#effective_column	Returns the column attribute of the range, except if the range is on the first line and there’s a byte order mark at the beginning of that line, in which case 1 is subtracted from the column value.
#final_pos, #move_pos, #move_pos_str, #range_between, #range_by_whole_lines, #range_with_comments, #range_with_comments_and_lines, #range_with_surrounding_comma, #range_with_surrounding_space, #source_range

`::RuboCop::Cop::AllowedPattern` - Included

#allowed_line?, #allowed_patterns, #cop_config_deprecated_methods_values, #cop_config_patterns_values,
#ignored_line?	Alias for AllowedPattern#allowed_line?.
#matches_allowed_pattern?,
#matches_ignored_pattern?	Alias for AllowedPattern#matches_allowed_pattern?.

`::RuboCop::Cop::CheckLineBreakable` - Included

#extract_breakable_node, #all_on_same_line?, #already_on_multiple_lines?, #breakable_collection?, #children_could_be_broken_up?, #contained_by_breakable_collection_on_same_line?, #contained_by_multiline_collection_that_could_be_broken_up?, #extract_breakable_node_from_elements, #extract_first_element_over_column_limit, #first_argument_is_heredoc?, #process_args, #safe_to_ignore?,
#shift_elements_for_heredoc_arg	If a send node contains a heredoc argument, splitting cannot happen after the heredoc or else it will cause a syntax error.
#within_column_limit?

`::RuboCop::Cop::Base` - Inherited

#add_global_offense	Adds an offense that has no particular location.
#add_offense	Adds an offense on the specified range (or node with an expression) Unless that offense is disabled for this range, a corrector will be yielded to provide the cop the opportunity to autocorrect the offense.
#begin_investigation	Called before any investigation.
#callbacks_needed,
#cop_config	Configuration Helpers.
#cop_name, #excluded_file?,
#external_dependency_checksum	This method should be overridden when a cop’s behavior depends on state that lives outside of these locations:
#inspect,
#message	Gets called if no message is specified when calling `add_offense` or `add_global_offense` Cops are discouraged to override this; instead pass your message directly.
#name	Alias for Base#cop_name.
#offenses,
#on_investigation_end	Called after all on_…
#on_new_investigation	Called before all on_…
#on_other_file	Called instead of all on_…
#parse	There should be very limited reasons for a Cop to do it’s own parsing.
#parser_engine,
#ready	Called between investigations.
#relevant_file?, #target_rails_version, #target_ruby_version, #annotate, #apply_correction, #attempt_correction,
#callback_argument	Reserved for Cop::Cop.
#complete_investigation	Called to complete an investigation.
#correct, #current_corrector,
#current_offense_locations	Reserved for Commissioner:
#current_offenses, #currently_disabled_lines, #custom_severity, #default_severity, #disable_uncorrectable, #enabled_line?, #file_name_matches_any?, #find_message, #find_severity, #range_for_original, #range_from_node_or_range, #reset_investigation, #use_corrector

`::RuboCop::Cop::AutocorrectLogic` - Included

#disable_offense, #disable_offense_at_end_of_line, #disable_offense_before_and_after, #disable_offense_with_eol_or_surround_comment, #max_line_length,
#range_by_lines	Expand the given range to include all of any lines it covers.
#range_of_first_line, #surrounding_heredoc, #surrounding_percent_array

`::RuboCop::Cop::IgnoredNode` - Included

#ignore_node, #ignored_node?, #part_of_ignored_node?, #ignored_nodes

Constructor Details

This class inherits a constructor from RuboCop::Cop::Base

Instance Attribute Details

#allow_heredoc? ⇒ `Boolean` (readonly, private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 219


def allow_heredoc?
  allowed_heredoc
end

#breakable_range (rw, private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 102


attr_accessor :breakable_range

Instance Method Details

#allowed_heredoc (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 223


def allowed_heredoc
  cop_config['AllowHeredoc']
end

#allowed_line?(line, line_index) ⇒ `Boolean` (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 183


def allowed_line?(line, line_index)
  matches_allowed_pattern?(line) ||
    shebang?(line, line_index) ||
    (heredocs && line_in_permitted_heredoc?(line_index.succ))
end

#breakable_block_range(block_node) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 135


def breakable_block_range(block_node)
  if block_node.arguments? && !block_node.lambda?
    block_node.arguments.loc.end
  else
    block_node.braces? ? block_node.loc.begin : block_node.loc.begin.adjust(begin_pos: 1)
  end
end

#breakable_range_after_semicolon(semicolon_token) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 143


def breakable_range_after_semicolon(semicolon_token)
  range = semicolon_token.pos
  end_pos = range.end_pos
  next_range = range_between(end_pos, end_pos + 1)
  return nil unless same_line?(next_range, range)

  next_char = next_range.source
  return nil if /[\r\n]/.match?(next_char)
  return nil if next_char == ';'

  next_range
end

#breakable_range_by_line_index (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 156


def breakable_range_by_line_index
  @breakable_range_by_line_index ||= {}
end

#check_directive_line(line, line_index) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 250


def check_directive_line(line, line_index)
  length_without_directive = line_length_without_directive(line)
  return if length_without_directive <= max

  range = max..(length_without_directive - 1)
  register_offense(
    source_range(
      processed_source.buffer,
      line_index + 1,
      range
    ),
    line,
    line_index,
    length: length_without_directive
  )
end

#check_for_breakable_block(block_node) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 125


def check_for_breakable_block(block_node)
  return unless block_node.single_line?

  line_index = block_node.loc.line - 1
  range = breakable_block_range(block_node)
  pos = range.begin_pos + 1

  breakable_range_by_line_index[line_index] = range_between(pos, pos + 1)
end

#check_for_breakable_node(node) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 104


def check_for_breakable_node(node)
  breakable_node = extract_breakable_node(node, max)
  return if breakable_node.nil?

  line_index = breakable_node.first_line - 1
  range = breakable_node.source_range

  existing = breakable_range_by_line_index[line_index]
  return if existing

  breakable_range_by_line_index[line_index] = range
end

#check_for_breakable_semicolons(processed_source) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 117


def check_for_breakable_semicolons(processed_source)
  tokens = processed_source.tokens.select { |t| t.type == :tSEMI }
  tokens.reverse_each do |token|
    range = breakable_range_after_semicolon(token)
    breakable_range_by_line_index[range.line - 1] = range if range
  end
end

#check_line(line, line_index) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 171


def check_line(line, line_index)
  return if line_length(line) <= max
  return if allowed_line?(line, line_index)

  if ignore_cop_directives? && directive_on_source_line?(line_index)
    return check_directive_line(line, line_index)
  end
  return check_uri_line(line, line_index) if allow_uri?

  register_offense(excess_range(nil, line, line_index), line, line_index)
end

#check_uri_line(line, line_index) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 267


def check_uri_line(line, line_index)
  uri_range = find_excessive_uri_range(line)
  return if uri_range && allowed_uri_position?(line, uri_range)

  register_offense(excess_range(uri_range, line, line_index), line, line_index)
end

#excess_range(uri_range, line, line_index) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 204


def excess_range(uri_range, line, line_index)
  excessive_position = if uri_range && uri_range.begin < max
                         uri_range.end
                       else
                         highlight_start(line)
                       end

  source_range(processed_source.buffer, line_index + 1,
               excessive_position...(line_length(line)))
end

#extract_heredocs(ast) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 227


def extract_heredocs(ast)
  return [] unless ast

  ast.each_node(:str, :dstr, :xstr).select(&:heredoc?).map do |node|
    body = node.location.heredoc_body
    delimiter = node.location.heredoc_end.source.strip
    [body.first_line...body.last_line, delimiter]
  end
end

#heredocs (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 160


def heredocs
  @heredocs ||= extract_heredocs(processed_source.ast)
end

#highlight_start(line) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 164


def highlight_start(line)
  # TODO: The max with 0 is a quick fix to avoid crashes when a line
  # begins with many tabs, but getting a correct highlighting range
  # when tabs are used for indentation doesn't work currently.
  [max - indentation_difference(line), 0].max
end

#line_in_heredoc?(line_number) ⇒ `Boolean` (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 246


def line_in_heredoc?(line_number)
  heredocs.any? { |range, _delimiter| range.cover?(line_number) }
end

#line_in_permitted_heredoc?(line_number) ⇒ `Boolean` (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 237


def line_in_permitted_heredoc?(line_number)
  return false unless allowed_heredoc

  heredocs.any? do |range, delimiter|
    range.cover?(line_number) &&
      (allowed_heredoc == true || allowed_heredoc.include?(delimiter))
  end
end

#max (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 215


def max
  cop_config['Max']
end

#on_array(node)

Alias for #on_potential_breakable_node.

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 83


alias on_array on_potential_breakable_node

#on_block(node) Also known as: #on_numblock

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 74


def on_block(node)
  check_for_breakable_block(node)
end

#on_def(node)

Alias for #on_potential_breakable_node.

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 86


alias on_def on_potential_breakable_node

#on_hash(node)

Alias for #on_potential_breakable_node.

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 84


alias on_hash on_potential_breakable_node

#on_investigation_end

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 94


def on_investigation_end
  processed_source.lines.each_with_index do |line, line_index|
    check_line(line, line_index)
  end
end

#on_new_investigation

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 88


def on_new_investigation
  return unless processed_source.raw_source.include?(';')

  check_for_breakable_semicolons(processed_source)
end

#on_numblock(node)

Alias for #on_block.

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 78


alias on_numblock on_block

#on_potential_breakable_node(node) Also known as: #on_array, #on_hash, #on_send, #on_def

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 80


def on_potential_breakable_node(node)
  check_for_breakable_node(node)
end

#on_send(node)

Alias for #on_potential_breakable_node.

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 85


alias on_send on_potential_breakable_node

#register_offense(loc, line, line_index, length: line_length(line)) (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 193


def register_offense(loc, line, line_index, length: line_length(line))
  message = format(MSG, length: length, max: max)

  self.breakable_range = breakable_range_by_line_index[line_index]

  add_offense(loc, message: message) do |corrector|
    self.max = line_length(line)
    corrector.insert_before(breakable_range, "\n") unless breakable_range.nil?
  end
end

#shebang?(line, line_index) ⇒ `Boolean` (private)

[ GitHub ]

# File 'lib/rubocop/cop/layout/line_length.rb', line 189


def shebang?(line, line_index)
  line_index.zero? && line.start_with?('#!')
end

Class: RuboCop::Cop::Layout::LineLength

Overview

Constant Summary

::RuboCop::Cop::Base - Inherited

::RuboCop::Cop::RangeHelp - Included

::RuboCop::Cop::Alignment - Included

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::RuboCop::Cop::Base - Inherited

Class Method Summary

::RuboCop::Cop::Base - Inherited

::RuboCop::ExcludeLimit - Extended

Instance Attribute Summary

::RuboCop::Cop::LineLengthHelp - Included

::RuboCop::Cop::Alignment - Included

::RuboCop::Cop::Base - Inherited

::RuboCop::Cop::AutocorrectLogic - Included

Instance Method Summary

::RuboCop::Cop::LineLengthHelp - Included

::RuboCop::Cop::Alignment - Included

::RuboCop::Cop::RangeHelp - Included

::RuboCop::Cop::AllowedPattern - Included

::RuboCop::Cop::CheckLineBreakable - Included

::RuboCop::Cop::Base - Inherited

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

Instance Attribute Details

#allow_heredoc? ⇒ Boolean (readonly, private)

#breakable_range (rw, private)

Instance Method Details

#allowed_heredoc (private)

#allowed_line?(line, line_index) ⇒ Boolean (private)

#breakable_block_range(block_node) (private)

#breakable_range_after_semicolon(semicolon_token) (private)

#breakable_range_by_line_index (private)

#check_directive_line(line, line_index) (private)

#check_for_breakable_block(block_node) (private)

#check_for_breakable_node(node) (private)

#check_for_breakable_semicolons(processed_source) (private)

#check_line(line, line_index) (private)

#check_uri_line(line, line_index) (private)

#excess_range(uri_range, line, line_index) (private)

#extract_heredocs(ast) (private)

#heredocs (private)

#highlight_start(line) (private)

#line_in_heredoc?(line_number) ⇒ Boolean (private)

#line_in_permitted_heredoc?(line_number) ⇒ Boolean (private)

#max (private)

#on_array(node)

#on_block(node) Also known as: #on_numblock

#on_def(node)

#on_hash(node)

#on_investigation_end

#on_new_investigation

#on_numblock(node)

#on_potential_breakable_node(node) Also known as: #on_array, #on_hash, #on_send, #on_def

#on_send(node)

#register_offense(loc, line, line_index, length: line_length(line)) (private)

#shebang?(line, line_index) ⇒ Boolean (private)

`::RuboCop::Cop::Base` - Inherited

`::RuboCop::Cop::RangeHelp` - Included

`::RuboCop::Cop::Alignment` - Included

`::RuboCop::Cop::AutoCorrector` - Extended

`::RuboCop::Cop::Base` - Inherited

`::RuboCop::Cop::Base` - Inherited

`::RuboCop::ExcludeLimit` - Extended

`::RuboCop::Cop::LineLengthHelp` - Included

`::RuboCop::Cop::Alignment` - Included

`::RuboCop::Cop::Base` - Inherited

`::RuboCop::Cop::AutocorrectLogic` - Included

`::RuboCop::Cop::LineLengthHelp` - Included

`::RuboCop::Cop::Alignment` - Included

`::RuboCop::Cop::RangeHelp` - Included

`::RuboCop::Cop::AllowedPattern` - Included

`::RuboCop::Cop::CheckLineBreakable` - Included

`::RuboCop::Cop::Base` - Inherited

`::RuboCop::Cop::AutocorrectLogic` - Included

`::RuboCop::Cop::IgnoredNode` - Included

#allow_heredoc? ⇒ `Boolean` (readonly, private)

#allowed_line?(line, line_index) ⇒ `Boolean` (private)

#line_in_heredoc?(line_number) ⇒ `Boolean` (private)

#line_in_permitted_heredoc?(line_number) ⇒ `Boolean` (private)

#shebang?(line, line_index) ⇒ `Boolean` (private)