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Class: RuboCop::Cop::Style::HashLikeCase

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::RuboCop::Cop::Base, ::RuboCop::ExcludeLimit, NodePattern::Macros, RuboCop::AST::Sexp
Instance Chain:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/style/hash_like_case.rb

Overview

Checks for places where case-when represents a simple 1:1 mapping and can be replaced with a hash lookup.

Examples:

MinBranchesCount: 3 (default)

# bad
case country
when 'europe'
  'http://eu.example.com'
when 'america'
  'http://us.example.com'
when 'australia'
  'http://au.example.com'
end

# good
SITES = {
  'europe'    => 'http://eu.example.com',
  'america'   => 'http://us.example.com',
  'australia' => 'http://au.example.com'
}
SITES[country]

MinBranchesCount: 4

# good
case country
when 'europe'
  'http://eu.example.com'
when 'america'
  'http://us.example.com'
when 'australia'
  'http://au.example.com'
end

Constant Summary

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

Class Attribute Summary

::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::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 an 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::MinBranchesCount - 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_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

#hash_like_case?(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/hash_like_case.rb', line 45

def_node_matcher :hash_like_case?, <<~PATTERN
  (case
    _
    (when
      ${str_type? sym_type?}
      $[!nil? recursive_basic_literal?])+ nil?)
PATTERN

#nodes_of_same_type?(nodes) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/hash_like_case.rb', line 65

def nodes_of_same_type?(nodes)
  nodes.all? { |node| node.type == nodes.first.type }
end

#on_case(node)

[ GitHub ]

  
# File 'lib/rubocop/cop/style/hash_like_case.rb', line 53

def on_case(node)
  return unless min_branches_count?(node)

  hash_like_case?(node) do |condition_nodes, body_nodes|
    if nodes_of_same_type?(condition_nodes) && nodes_of_same_type?(body_nodes)
      add_offense(node)
    end
  end
end