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Class: RuboCop::Cop::Lint::AmbiguousOperator

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:
Inherits: RuboCop::Cop::Base
Defined in: lib/rubocop/cop/lint/ambiguous_operator.rb

Overview

Checks for ambiguous operators in the first argument of a method invocation without parentheses.

Examples:

# bad

# The `*` is interpreted as a splat operator but it could possibly be
# a `*` method invocation (i.e. `do_something.*(some_array)`).
do_something *some_array
# good

# With parentheses, there's no ambiguity.
do_something(*some_array)

Constant Summary

  • AMBIGUITIES =
    # File 'lib/rubocop/cop/lint/ambiguous_operator.rb', line 26
    {
      '+'  => { actual: 'positive number', possible: 'an addition' },
      '-'  => { actual: 'negative number', possible: 'a subtraction' },
      '*'  => { actual: 'splat',           possible: 'a multiplication' },
      '&'  => { actual: 'block',           possible: 'a binary AND' },
      '**' => { actual: 'keyword splat',   possible: 'an exponent' }
    }.each do |key, hash|
      hash[:operator] = key
    end
  • MSG_FORMAT =
    # File 'lib/rubocop/cop/lint/ambiguous_operator.rb', line 36
    'Ambiguous %<actual>s operator. Parenthesize the method ' \
    "arguments if it's surely a %<actual>s operator, or add " \
    'a whitespace to the right of the `%<operator>s` if it ' \
    'should be %<possible>s.'

::RuboCop::Cop::Base - Inherited

EMPTY_OFFENSES, RESTRICT_ON_SEND

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::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::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

Class Method Details

.autocorrect_incompatible_with

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/ambiguous_operator.rb', line 41

def self.autocorrect_incompatible_with
  [Naming::BlockForwarding]
end

Instance Method Details

#find_offense_node_by(diagnostic) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/ambiguous_operator.rb', line 64

def find_offense_node_by(diagnostic)
  ast = processed_source.ast
  ast.each_node(:splat, :block_pass, :kwsplat) do |node|
    next unless offense_position?(node, diagnostic)

    offense_node = offense_node(node)
    return offense_node if offense_node
  end

  ast.each_node(:send).find do |send_node|
    first_argument = send_node.first_argument

    first_argument &&
      offense_position?(first_argument, diagnostic) &&
      unary_operator?(first_argument, diagnostic)
  end
end

#message(diagnostic) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/ambiguous_operator.rb', line 82

def message(diagnostic)
  operator = diagnostic.location.source
  hash = AMBIGUITIES[operator]
  format(MSG_FORMAT, hash)
end

#offense_node(node) (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/ambiguous_operator.rb', line 92

def offense_node(node)
  case node.type
  when :splat, :block_pass
    node.parent
  when :kwsplat
    node.parent.parent
  end
end

#offense_position?(node, diagnostic) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/ambiguous_operator.rb', line 88

def offense_position?(node, diagnostic)
  node.source_range.begin_pos == diagnostic.location.begin_pos
end

#on_new_investigation

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/ambiguous_operator.rb', line 45

def on_new_investigation
  processed_source.diagnostics.each do |diagnostic|
    next unless diagnostic.reason == :ambiguous_prefix

    offense_node = find_offense_node_by(diagnostic)
    next unless offense_node

    message = message(diagnostic)

    add_offense(
      diagnostic.location, message: message, severity: diagnostic.level
    ) do |corrector|
      add_parentheses(offense_node, corrector)
    end
  end
end

#unary_operator?(node, diagnostic) ⇒ Boolean (private)

[ GitHub ]

  
# File 'lib/rubocop/cop/lint/ambiguous_operator.rb', line 101

def unary_operator?(node, diagnostic)
  node.source.start_with?(diagnostic.arguments[:prefix])
end