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Class: RuboCop::Cop::Layout::TrailingWhitespace

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:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/layout/trailing_whitespace.rb

Overview

Looks for trailing whitespace in the source code.

Examples:

# The line in this example contains spaces after the 0.
# bad
x = 0

# The line in this example ends directly after the 0.
# good
x = 0

AllowInHeredoc: false (default)

# The line in this example contains spaces after the 0.
# bad
code = <<~RUBY
  x = 0
RUBY

# ok
code = <<~RUBY
  x = 0 #{}
RUBY

# good
trailing_whitespace = ' '
code = <<~RUBY
  x = 0#{trailing_whitespace}
RUBY

AllowInHeredoc: true

# The line in this example contains spaces after the 0.
# good
code = <<~RUBY
  x = 0
RUBY

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

::RuboCop::Cop::Heredoc - Included

OPENING_DELIMITER

Class Attribute Summary

::RuboCop::Cop::AutoCorrector - Extended

::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.

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

Returns an url to view this cops documentation online.

.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

Instance Method Summary

::RuboCop::Cop::Heredoc - Included

::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::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

Actually private methods.

#use_corrector

::RuboCop::Cop::AutocorrectLogic - Included

::RuboCop::Cop::IgnoredNode - Included

Constructor Details

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

Instance Attribute Details

#skip_heredoc?Boolean (readonly, private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 99

def skip_heredoc?
  cop_config.fetch('AllowInHeredoc', false)
end

Instance Method Details

#extract_heredocs(ast) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 112

def extract_heredocs(ast)
  return [] unless ast

  heredocs = []
  ast.each_node(:str, :dstr, :xstr) do |node|
    next unless node.heredoc?

    body = node.location.heredoc_body
    heredocs << [node, body.first_line...body.last_line]
  end
  heredocs
end

#find_heredoc(line_number) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 103

def find_heredoc(line_number)
  heredocs.each { |node, r| return node if r.include?(line_number) }
  nil
end

#heredocs (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 108

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

#offense_range(lineno, line) (private)

[ GitHub ]

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

def offense_range(lineno, line)
  source_range(processed_source.buffer, lineno, (line.rstrip.length)...(line.length))
end

#on_heredoc(_node)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 57

def on_heredoc(_node); end

#on_new_investigation

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 49

def on_new_investigation
  processed_source.lines.each_with_index do |line, index|
    next unless line.end_with?(' ', "\t")

    process_line(line, index + 1)
  end
end

#process_line(line, lineno) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 61

def process_line(line, lineno)
  heredoc = find_heredoc(lineno)
  return if skip_heredoc? && heredoc

  range = offense_range(lineno, line)
  add_offense(range) do |corrector|
    if heredoc
      process_line_in_heredoc(corrector, range, heredoc)
    else
      corrector.remove(range)
    end
  end
end

#process_line_in_heredoc(corrector, range, heredoc) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 75

def process_line_in_heredoc(corrector, range, heredoc)
  indent_level = indent_level(find_heredoc(range.line).loc.heredoc_body.source)
  whitespace_only = whitespace_only?(range)
  if whitespace_only && whitespace_is_indentation?(range, indent_level)
    corrector.remove(range)
  elsif !static?(heredoc)
    range = range_between(range.begin_pos + indent_level, range.end_pos) if whitespace_only
    corrector.wrap(range, "\#{'", "'}")
  end
end

#static?(heredoc) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 95

def static?(heredoc)
  heredoc.source.end_with? "'"
end

#whitespace_is_indentation?(range, level) ⇒ Boolean (private)

[ GitHub ]

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

def whitespace_is_indentation?(range, level)
  range.source[/[ \t]+/].length <= level
end

#whitespace_only?(range) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/layout/trailing_whitespace.rb', line 90

def whitespace_only?(range)
  source = range_with_surrounding_space(range).source
  source.start_with?("\n") && source.end_with?("\n")
end