Class: RuboCop::Cop::Lint::RedundantSplatExpansion

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

Overview

This cop checks for unneeded usages of splat expansion

Examples:


# bad
a = *[1, 2, 3]
a = *'a'
a = *1
['a', 'b', *%w(c d e), 'f', 'g']

# good
c = [1, 2, 3]
a = *c
a, b = *c
a, *b = *c
a = *1..10
a = ['a']
['a', 'b', 'c', 'd', 'e', 'f', 'g']

# bad
do_something(*['foo', 'bar', 'baz'])

# good
do_something('foo', 'bar', 'baz')

# bad
begin
  foo
rescue *[StandardError, ApplicationError]
  bar
end

# good
begin
  foo
rescue StandardError, ApplicationError
  bar
end

# bad
case foo
when *[1, 2, 3]
  bar
else
  baz
end

# good
case foo
when 1, 2, 3
  bar
else
  baz
end

AllowPercentLiteralArrayArgument: true (default)


# good
do_something(*%w[foo bar baz])

AllowPercentLiteralArrayArgument: false


# bad
do_something(*%w[foo bar baz])

Constant Summary collapse

MSG =
'Replace splat expansion with comma separated values.'
ARRAY_PARAM_MSG =
'Pass array contents as separate arguments.'
PERCENT_W =
'%w'
PERCENT_CAPITAL_W =
'%W'
PERCENT_I =
'%i'
PERCENT_CAPITAL_I =
'%I'
ASSIGNMENT_TYPES =
%i[lvasgn ivasgn cvasgn gvasgn].freeze

Constants inherited from Base

Base::RESTRICT_ON_SEND

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, #parse, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

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

silence_warnings

Constructor Details

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

Instance Method Details

#array_new?(node) ⇒ Object


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# File 'lib/rubocop/cop/lint/redundant_splat_expansion.rb', line 83

def_node_matcher :array_new?, <<~PATTERN
  {
    $(send (const {nil? cbase} :Array) :new ...)
    $(block (send (const {nil? cbase} :Array) :new ...) ...)
  }
PATTERN

#literal_expansion(node) ⇒ Object


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# File 'lib/rubocop/cop/lint/redundant_splat_expansion.rb', line 91

def_node_matcher :literal_expansion, <<~PATTERN
  (splat {$({str dstr int float array} ...) (block $#array_new? ...) $#array_new?} ...)
PATTERN

#on_splat(node) ⇒ Object


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# File 'lib/rubocop/cop/lint/redundant_splat_expansion.rb', line 95

def on_splat(node)
  redundant_splat_expansion(node) do
    if array_splat?(node) && (method_argument?(node) || part_of_an_array?(node))
      return if allow_percent_literal_array_argument? &&
                use_percent_literal_array_argument?(node)

      add_offense(node, message: ARRAY_PARAM_MSG) do |corrector|
        autocorrect(corrector, node)
      end
    else
      add_offense(node) { |corrector| autocorrect(corrector, node) }
    end
  end
end