Class: RuboCop::Cop::Lint::AmbiguousRange

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Defined in:
lib/rubocop/cop/lint/ambiguous_range.rb

Overview

Checks for ambiguous ranges.

Ranges have quite low precedence, which leads to unexpected behavior when using a range with other operators. This cop avoids that by making ranges explicit by requiring parenthesis around complex range boundaries (anything that is not a literal: numerics, strings, symbols, etc.).

This cop can be configured with RequireParenthesesForMethodChains in order to specify whether method chains (including self.foo) should be wrapped in parens by this cop.

Note
 Regardless of this configuration, if a method receiver is a basic literal value, it will be wrapped in order to prevent the ambiguity of 1..2.to_a.

Examples:

# bad
x || 1..2
(x || 1..2)
1..2.to_a

# good, unambiguous
1..2
'a'..'z'
:bar..:baz
MyClass::MIN..MyClass::MAX
@min..@max
a..b
-a..b

# good, ambiguity removed
x || (1..2)
(x || 1)..2
(x || 1)..(y || 2)
(1..2).to_a

RequireParenthesesForMethodChains: false (default)

# good
a.foo..b.bar
(a.foo)..(b.bar)

RequireParenthesesForMethodChains: true

# bad
a.foo..b.bar

# good
(a.foo)..(b.bar)

Cop Safety Information:

  • The cop autocorrects by wrapping the entire boundary in parentheses, which makes the outcome more explicit but is possible to not be the intention of the programmer. For this reason, this cop’s autocorrect is unsafe (it will not change the behavior of the code, but will not necessarily match the intent of the program).

Constant Summary collapse

MSG = 
'Wrap complex range boundaries with parentheses to avoid ambiguity.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

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

#on_irange(node) ⇒ Object Also known as: on_erange 



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

def on_irange(node)
  each_boundary(node) do |boundary|
    next if acceptable?(boundary)

    add_offense(boundary) do |corrector|
      corrector.wrap(boundary, '(', ')')
    end
  end
end