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Class: RuboCop::Cop::Style::ItBlockParameter

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

Overview

Checks for blocks with one argument where it block parameter can be used.

It provides three EnforcedStyle options:

  1. only_numbered_parameters (default) …​ Detects only numbered block parameters.

  2. always …​ Always uses the it block parameter.

  3. disallow …​ Disallows the it block parameter.

A single numbered parameter is detected when only_numbered_parameters or always.

Examples:

EnforcedStyle: only_numbered_parameters (default)

# bad
block { do_something(_1) }

# good
block { do_something(it) }
block { |named_param| do_something(named_param) }

EnforcedStyle: always

# bad
block { do_something(_1) }
block { |named_param| do_something(named_param) }

# good
block { do_something(it) }

EnforcedStyle: disallow

# bad
block { do_something(it) }

# good
block { do_something(_1) }
block { |named_param| do_something(named_param) }

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

::RuboCop::Cop::ConfigurableEnforcedStyle - Included

SYMBOL_TO_STRING_CACHE

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 a 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::ConfigurableEnforcedStyle - Included

::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_gem_version

Returns a gems locked versions (i.e.

#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

Instance Method Details

#find_block_variables(node, block_argument_name) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/it_block_parameter.rb', line 92

def find_block_variables(node, block_argument_name)
  node.each_descendant(:lvar).select do |descendant|
    descendant.source == block_argument_name
  end
end

#on_block(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/it_block_parameter.rb', line 50

def on_block(node)
  return unless style == :always
  return unless node.arguments.one?

  # `restarg`, `kwrestarg`, `blockarg` nodes can return early.
  return unless node.first_argument.arg_type?

  variables = find_block_variables(node, node.first_argument.source)

  variables.each do |variable|
    add_offense(variable, message: MSG_USE_IT_BLOCK_PARAMETER) do |corrector|
      corrector.remove(node.arguments)
      corrector.replace(variable, 'it')
    end
  end
end

#on_itblock(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/it_block_parameter.rb', line 80

def on_itblock(node)
  return unless style == :disallow

  variables = find_block_variables(node, 'it')

  variables.each do |variable|
    add_offense(variable, message: MSG_AVOID_IT_BLOCK_PARAMETER)
  end
end

#on_numblock(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/it_block_parameter.rb', line 67

def on_numblock(node)
  return if style == :disallow
  return unless node.children[1] == 1

  variables = find_block_variables(node, '_1')

  variables.each do |variable|
    add_offense(variable, message: MSG_USE_IT_BLOCK_PARAMETER) do |corrector|
      corrector.replace(variable, 'it')
    end
  end
end