Class: RuboCop::Cop::Style::FormatString

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

Overview

Enforces the use of a single string formatting utility. Valid options include ‘Kernel#format`, `Kernel#sprintf`, and `String#%`.

The detection of ‘String#%` cannot be implemented in a reliable manner for all cases, so only two scenarios are considered - if the first argument is a string literal and if the second argument is an array literal.

Autocorrection will be applied when using argument is a literal or known built-in conversion methods such as ‘to_d`, `to_f`, `to_h`, `to_i`, `to_r`, `to_s`, and `to_sym` on variables, provided that their return value is not an array. For example, when using `to_s`, `’%s’ % [1, 2, 3].to_s` can be autocorrected without any incompatibility:

source,ruby

‘%s’ % [1, 2, 3] #=> ‘1’ format(‘%s’, [1, 2, 3]) #=> ‘[1, 2, 3]’ ‘%s’ % [1, 2, 3].to_s #=> ‘[1, 2, 3]’

Examples:

EnforcedStyle: format (default)

# bad
puts sprintf('%10s', 'foo')
puts '%10s' % 'foo'

# good
puts format('%10s', 'foo')

EnforcedStyle: sprintf

# bad
puts format('%10s', 'foo')
puts '%10s' % 'foo'

# good
puts sprintf('%10s', 'foo')

EnforcedStyle: percent

# bad
puts format('%10s', 'foo')
puts sprintf('%10s', 'foo')

# good
puts '%10s' % 'foo'

Constant Summary collapse

MSG = 
'Favor `%<prefer>s` over `%<current>s`.'
RESTRICT_ON_SEND = 
%i[format sprintf %].freeze
AUTOCORRECTABLE_METHODS =

Known conversion methods whose return value is not an array.

%i[to_d to_f to_h to_i to_r to_s to_sym].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods included from ConfigurableEnforcedStyle

#alternative_style, #alternative_styles, #ambiguous_style_detected, #correct_style_detected, #detected_style, #detected_style=, #no_acceptable_style!, #no_acceptable_style?, #opposite_style_detected, #style, #style_configured?, #style_detected, #style_parameter_name, #supported_styles, #unexpected_style_detected

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, #always_autocorrect?, autocorrect_incompatible_with, badge, #begin_investigation, callbacks_needed, #callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #contextual_autocorrect?, #cop_config, cop_name, #cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, #inspect, joining_forces, lint?, match?, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #parser_engine, #ready, #relevant_file?, requires_gem, #string_literals_frozen_by_default?, 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?, #autocorrect_with_disable_uncorrectable?, #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

#formatter(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/format_string.rb', line 61

def_node_matcher :formatter, <<~PATTERN
  {
    (send nil? ${:sprintf :format} _ _ ...)
    (send {str dstr} $:% ... )
    (send !nil? $:% {array hash})
  }
PATTERN

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/format_string.rb', line 74

def on_send(node)
  formatter(node) do |selector|
    detected_style = selector == :% ? :percent : selector

    return if detected_style == style

    add_offense(node.loc.selector, message: message(detected_style)) do |corrector|
      autocorrect(corrector, node)
    end
  end
end

#variable_argument?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/format_string.rb', line 70

def_node_matcher :variable_argument?, <<~PATTERN
  (send {str dstr} :% #autocorrectable?)
PATTERN