Class: RuboCop::Cop::Lint::RedundantSafeNavigation
Relationships & Source Files | |
Super Chains via Extension / Inclusion / Inheritance | |
Class Chain:
self,
::RuboCop::Cop::AutoCorrector ,
::RuboCop::Cop::Base ,
::RuboCop::ExcludeLimit ,
NodePattern::Macros,
RuboCop::AST::Sexp
|
|
Instance Chain:
self,
::RuboCop::Cop::AllowedMethods ,
::RuboCop::Cop::Base ,
::RuboCop::Cop::AutocorrectLogic ,
::RuboCop::Cop::IgnoredNode ,
::RuboCop::Util ,
RuboCop::AST::Sexp
|
|
Inherits: |
RuboCop::Cop::Base
|
Defined in: | lib/rubocop/cop/lint/redundant_safe_navigation.rb |
Overview
Checks for redundant safe navigation calls.
Use cases where a constant, named in camel case for classes and modules is nil
are rare,
and an offense is not detected when the receiver is a constant. The detection also applies
to self
, and to literal receivers, except for nil
.
For all receivers, the instance_of?
, kind_of?
, is_a?
, eql?
, respond_to?
,
and equal?
methods are checked by default.
These are customizable with ::RuboCop::Cop::AllowedMethods
option.
The ::RuboCop::Cop::AllowedMethods
option specifies nil-safe methods,
in other words, it is a method that is allowed to skip safe navigation.
Note that the AllowedMethod
option is not an option that specifies methods
for which to suppress (allow) this cop’s check.
In the example below, the safe navigation operator (&.
) is unnecessary
because NilClass
has methods like respond_to?
and is_a?
.
The InferNonNilReceiver
option specifies whether to look into previous code
paths to infer if the receiver can’t be nil. This check is unsafe because the receiver
can be redefined between the safe navigation call and previous regular method call.
It does the inference only in the current scope, e.g. within the same method definition etc.
The AdditionalNilMethods
option specifies additional custom methods which are
defined on NilClass
. When InferNonNilReceiver
is set, they are used to determine
whether the receiver can be nil.
Constant Summary
-
GUARANTEED_INSTANCE_METHODS =
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 158%i[to_s to_i to_f to_a to_h].freeze
-
MSG =
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 149'Redundant safe navigation detected, use `.` instead.'
-
MSG_LITERAL =
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 150'Redundant safe navigation with default literal detected.'
-
MSG_NON_NIL =
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 151'Redundant safe navigation on non-nil receiver (detected by analyzing ' \ 'previous code/method invocations).'
-
NIL_SPECIFIC_METHODS =
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 154(nil.methods - Object.new.methods).to_set.freeze
-
SNAKE_CASE =
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 156/\A[[:digit:][:upper:]_]+\z/.freeze
::RuboCop::Cop::Base
- Inherited
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 |
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 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
- #infer_non_nil_receiver? ⇒ Boolean readonly private
::RuboCop::Cop::AllowedMethods
- Included
::RuboCop::Cop::Base
- Inherited
::RuboCop::Cop::AutocorrectLogic
- Included
Instance Method Summary
- #conversion_with_default?(node)
- #on_csend(node)
- #on_or(node)
- #respond_to_nil_specific_method?(node)
- #additional_nil_methods private
- #assume_receiver_instance_exists?(receiver) ⇒ Boolean private
- #check?(node) ⇒ Boolean private
- #condition?(parent, node) ⇒ Boolean private
- #guaranteed_instance?(node) ⇒ Boolean private
::RuboCop::Cop::AllowedMethods
- 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 |
#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 Attribute Details
#infer_non_nil_receiver? ⇒ Boolean
(readonly, private)
[ GitHub ]
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 248
def infer_non_nil_receiver? cop_config['InferNonNilReceiver'] end
Instance Method Details
#additional_nil_methods (private)
[ GitHub ]# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 252
def additional_nil_methods @additional_nil_methods ||= Array(cop_config.fetch('AdditionalNilMethods', []).map(&:to_sym)) end
#assume_receiver_instance_exists?(receiver) ⇒ Boolean
(private)
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 216
def assume_receiver_instance_exists?(receiver) return true if receiver.const_type? && !receiver.short_name.match?(SNAKE_CASE) receiver.self_type? || (receiver.literal? && !receiver.nil_type?) end
#check?(node) ⇒ Boolean
(private)
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 233
def check?(node) return false unless allowed_method?(node.method_name) parent = node.parent return false unless parent condition?(parent, node) || parent.operator_keyword? || (parent.send_type? && parent.negation_method?) end
#condition?(parent, node) ⇒ Boolean
(private)
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 244
def condition?(parent, node) (parent.conditional? || parent.post_condition_loop?) && parent.condition == node end
#conversion_with_default?(node)
[ GitHub ]# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 166
def_node_matcher :conversion_with_default?, <<~PATTERN { (or $(csend _ :to_h) (hash)) (or (block $(csend _ :to_h) ...) (hash)) (or $(csend _ :to_a) (array)) (or $(csend _ :to_i) (int 0)) (or $(csend _ :to_f) (float 0.0)) (or $(csend _ :to_s) (str empty?)) } PATTERN
#guaranteed_instance?(node) ⇒ Boolean
(private)
# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 222
def guaranteed_instance?(node) receiver = if node.any_block_type? node.send_node else node end return false unless receiver.send_type? GUARANTEED_INSTANCE_METHODS.include?(receiver.method_name) end
#on_csend(node)
[ GitHub ]# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 178
def on_csend(node) range = node.loc.dot if infer_non_nil_receiver? checker = Lint::Utils::NilReceiverChecker.new(node.receiver, additional_nil_methods) if checker.cant_be_nil? add_offense(range, message: MSG_NON_NIL) { |corrector| corrector.replace(range, '.') } return end end unless assume_receiver_instance_exists?(node.receiver) return if !guaranteed_instance?(node.receiver) && !check?(node) return if respond_to_nil_specific_method?(node) end add_offense(range) { |corrector| corrector.replace(range, '.') } end
#on_or(node)
[ GitHub ]# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 200
def on_or(node) conversion_with_default?(node) do |send_node| range = send_node.loc.dot.begin.join(node.source_range.end) add_offense(range, message: MSG_LITERAL) do |corrector| corrector.replace(send_node.loc.dot, '.') range_with_default = node.lhs.source_range.end.begin.join(node.source_range.end) corrector.remove(range_with_default) end end end
#respond_to_nil_specific_method?(node)
[ GitHub ]# File 'lib/rubocop/cop/lint/redundant_safe_navigation.rb', line 161
def_node_matcher :respond_to_nil_specific_method?, <<~PATTERN (csend _ :respond_to? (sym %NIL_SPECIFIC_METHODS)) PATTERN