Class: RuboCop::Cop::Style::MapIntoArray
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::RangeHelp ,
::RuboCop::Cop::Base ,
::RuboCop::Cop::AutocorrectLogic ,
::RuboCop::Cop::IgnoredNode ,
::RuboCop::Util ,
RuboCop::AST::Sexp
|
|
Inherits: |
RuboCop::Cop::Base
|
Defined in: | lib/rubocop/cop/style/map_into_array.rb |
Overview
Checks for usages of each
with <<
, push
, or append
which
can be replaced by map
.
If PreferredMethods
is configured for map
in Style/CollectionMethods
,
this cop uses the specified method for replacement.
Note
|
The return value of Enumerable#each is self , whereas the
return value of Enumerable#map is an Array . They are not autocorrected
when a return value could be used because these types differ.
|
Note
|
It only detects when the mapping destination is a local variable initialized as an empty array and referred to only by the pushing operation. This is because, if not, it’s challenging to statically guarantee that the mapping destination variable remains an empty array: |
ret = []
src.each { |e| ret << e * 2 } # `<<` method may mutate `ret`
dest = []
src.each { |e| dest << transform(e, dest) } # `transform` method may mutate `dest`
Constant Summary
-
MSG =
# File 'lib/rubocop/cop/style/map_into_array.rb', line 54'Use `%<new_method_name>s` instead of `each` to map elements into an array.'
::RuboCop::Cop::Base
- Inherited
EMPTY_OFFENSES, RESTRICT_ON_SEND
::RuboCop::Cop::RangeHelp
- Included
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 |
.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
::RuboCop::Cop::Base
- Inherited
::RuboCop::Cop::AutocorrectLogic
- Included
Instance Method Summary
- #after_leaving_scope(scope, _variable_table)
- #each_block_with_push?(node)
- #empty_array_asgn?(node)
- #lvar_ref?(node, name)
- #on_block(node) (also: #on_numblock)
-
#on_numblock(node)
Alias for #on_block.
- #correct_push_node(corrector, push_node) private
- #correct_return_value_handling(corrector, block, dest_var) private
- #dest_used_only_for_mapping?(block, dest_var, asgn) ⇒ Boolean private
- #find_closest_assignment(block, dest_var) private
- #find_dest_var(block) private
- #new_method_name private
- #register_offense(block, dest_var, asgn) private
- #remove_assignment(corrector, asgn) private
- #return_value_used?(node) ⇒ Boolean private
::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 |
#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
Constructor Details
This class inherits a constructor from RuboCop::Cop::Base
Class Method Details
.joining_forces
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 71
def self.joining_forces VariableForce end
Instance Method Details
#after_leaving_scope(scope, _variable_table)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 75
def after_leaving_scope(scope, _variable_table) (@scopes ||= []) << scope end
#correct_push_node(corrector, push_node) (private)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 155
def correct_push_node(corrector, push_node) range = push_node.source_range arg_range = push_node.first_argument.source_range corrector.remove(range_between(range.begin_pos, arg_range.begin_pos)) corrector.remove(range_between(arg_range.end_pos, range.end_pos)) end
#correct_return_value_handling(corrector, block, dest_var) (private)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 163
def correct_return_value_handling(corrector, block, dest_var) next_node = block.right_sibling if lvar_ref?(next_node, dest_var.name) corrector.remove(range_with_surrounding_space(next_node.source_range, side: :left)) end corrector.insert_before(block, "#{dest_var.name} = ") end
#dest_used_only_for_mapping?(block, dest_var, asgn) ⇒ Boolean
(private)
# File 'lib/rubocop/cop/style/map_into_array.rb', line 108
def dest_used_only_for_mapping?(block, dest_var, asgn) range = asgn.source_range.join(block.source_range) asgn.parent.equal?(block.parent) && dest_var.references.one? { |r| range.contains?(r.node.source_range) } && dest_var.assignments.one? { |a| range.contains?(a.node.source_range) } end
#each_block_with_push?(node)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 57
def_node_matcher :each_block_with_push?, <<-PATTERN [ ^({begin kwbegin} ...) ({block numblock} (send _ :each) _ (send (lvar _) {:<< :push :append} _)) ] PATTERN
#empty_array_asgn?(node)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 66
def_node_matcher :empty_array_asgn?, '(lvasgn _ (array))'
#find_closest_assignment(block, dest_var) (private)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 102
def find_closest_assignment(block, dest_var) dest_var.assignments.reverse_each.lazy.map(&:node).find do |node| node.source_range.end_pos < block.source_range.begin_pos end end
#find_dest_var(block) (private)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 94
def find_dest_var(block) node = block.body.receiver name = node.children.first candidates = @scopes.lazy.filter_map { |s| s.variables[name] } candidates.find { |v| v.references.any? { |n| n.node.equal?(node) } } end
#lvar_ref?(node, name)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 69
def_node_matcher :lvar_ref?, '(lvar %1)'
#new_method_name (private)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 127
def new_method_name default = 'map' alternative = config.for_cop('Style/CollectionMethods').dig('PreferredMethods', default) alternative || default end
#on_block(node) Also known as: #on_numblock
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 79
def on_block(node) return unless each_block_with_push?(node) dest_var = find_dest_var(node) return unless (asgn = find_closest_assignment(node, dest_var)) return unless empty_array_asgn?(asgn) return unless dest_used_only_for_mapping?(node, dest_var, asgn) register_offense(node, dest_var, asgn) end
#on_numblock(node)
Alias for #on_block.
# File 'lib/rubocop/cop/style/map_into_array.rb', line 90
alias on_numblock on_block
#register_offense(block, dest_var, asgn) (private)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 116
def register_offense(block, dest_var, asgn) add_offense(block, message: format(MSG, new_method_name: new_method_name)) do |corrector| next if return_value_used?(block) corrector.replace(block.send_node.selector, new_method_name) remove_assignment(corrector, asgn) correct_push_node(corrector, block.body) correct_return_value_handling(corrector, block, dest_var) end end
#remove_assignment(corrector, asgn) (private)
[ GitHub ]# File 'lib/rubocop/cop/style/map_into_array.rb', line 148
def remove_assignment(corrector, asgn) range = range_with_surrounding_space(asgn.source_range, side: :right) range = range_with_surrounding_space(range, side: :right, newlines: false) corrector.remove(range) end
#return_value_used?(node) ⇒ Boolean
(private)
# File 'lib/rubocop/cop/style/map_into_array.rb', line 133
def return_value_used?(node) parent = node.parent case parent&.type when nil false when :begin, :kwbegin !node.right_sibling && return_value_used?(parent) when :block, :numblock !parent.void_context? else true end end