Class: RuboCop::Cop::Style::ArrayCoercion

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Defined in:
lib/rubocop/cop/style/array_coercion.rb

Overview

This cop enforces the use of `Array()` instead of explicit `Array` check or `[*var]`.

This cop is disabled by default because false positive will occur if the argument of `Array()` is not an array (e.g. Hash, Set), an array will be returned as an incompatibility result.

Examples:

# bad
paths = [paths] unless paths.is_a?(Array)
paths.each { |path| do_something(path) }

# bad (always creates a new Array instance)
[*paths].each { |path| do_something(path) }

# good (and a bit more readable)
Array(paths).each { |path| do_something(path) }

Constant Summary collapse

SPLAT_MSG =
'Use `Array(%<arg>s)` instead of `[*%<arg>s]`.'
CHECK_MSG =
'Use `Array(%<arg>s)` instead of explicit `Array` check.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from AutocorrectLogic

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

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

add_parentheses, args_begin, args_end, begins_its_line?, comment_line?, comment_lines?, double_quotes_required?, escape_string, first_part_of_call_chain, indent, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, hidden_dir?, hidden_file?, hidden_file_in_not_hidden_dir?, match_path?, maybe_hidden_file?, relative_path, smart_path

Constructor Details

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

Instance Method Details

#on_array(node) ⇒ Object


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# File 'lib/rubocop/cop/style/array_coercion.rb', line 43

def on_array(node)
  return unless node.square_brackets?

  array_splat?(node) do |arg_node|
    message = format(SPLAT_MSG, arg: arg_node.source)
    add_offense(node, message: message) do |corrector|
      corrector.replace(node, "Array(#{arg_node.source})")
    end
  end
end

#on_if(node) ⇒ Object


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# File 'lib/rubocop/cop/style/array_coercion.rb', line 54

def on_if(node)
  unless_array?(node) do |var_a, var_b, var_c|
    if var_a == var_b && var_c == var_b
      message = format(CHECK_MSG, arg: var_a)
      add_offense(node, message: message) do |corrector|
        corrector.replace(node, "#{var_a} = Array(#{var_a})")
      end
    end
  end
end