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Class: RuboCop::Cop::Style::MapToHash

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/style/map_to_hash.rb

Overview

Looks for uses of map.to_h or collect.to_h that could be written with just to_h in Ruby >= 2.6.

Note
Style/HashTransformKeys and Style/HashTransformValues will also change this pattern if only hash keys or hash values are being transformed.

Examples:

# bad
something.map { |v| [v, v * 2] }.to_h

# good
something.to_h { |v| [v, v * 2] }

# bad
{foo: bar}.collect { |k, v| [k.to_s, v.do_something] }.to_h

# good
{foo: bar}.to_h { |k, v| [k.to_s, v.do_something] }

Cop Safety Information:

  • This cop is unsafe, as it can produce false positives if the receiver is not an Enumerable.

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::RangeHelp - Included

BYTE_ORDER_MARK, NOT_GIVEN

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::TargetRubyVersion - Extended

::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::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

Class Method Details

.autocorrect_incompatible_with

[ GitHub ]

  
# File 'lib/rubocop/cop/style/map_to_hash.rb', line 48

def self.autocorrect_incompatible_with
  [Layout::SingleLineBlockChain]
end

Instance Method Details

#autocorrect(corrector, to_h, map) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/map_to_hash.rb', line 68

def autocorrect(corrector, to_h, map)
  removal_range = range_between(to_h.loc.dot.begin_pos, to_h.loc.selector.end_pos)

  corrector.remove(range_with_surrounding_space(removal_range, side: :left))
  if (map_dot = map.loc.dot)
    corrector.replace(map_dot, to_h.loc.dot.source)
  end
  corrector.replace(map.loc.selector, 'to_h')
end

#map_to_h(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/map_to_hash.rb', line 41

def_node_matcher :map_to_h, <<~PATTERN
  {
    $(call ({block numblock} $(call _ {:map :collect}) ...) :to_h)
    $(call $(call _ {:map :collect} (block_pass sym)) :to_h)
  }
PATTERN

#on_csend(node)

Alias for #on_send.

[ GitHub ]

  
# File 'lib/rubocop/cop/style/map_to_hash.rb', line 63

alias on_csend on_send

#on_send(node) Also known as: #on_csend

[ GitHub ]

  
# File 'lib/rubocop/cop/style/map_to_hash.rb', line 52

def on_send(node)
  return unless (to_h_node, map_node = map_to_h(node))

  message = format(MSG, method: map_node.loc.selector.source, dot: to_h_node.loc.dot.source)
  add_offense(map_node.loc.selector, message: message) do |corrector|
    # If the `to_h` call already has a block, do not autocorrect.
    next if to_h_node.block_literal?

    autocorrect(corrector, to_h_node, map_node)
  end
end