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

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

Overview

This cop checks for ambiguous ranges.

Ranges have quite low precedence, which leads to unexpected behaviour 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)

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

#add_global_offense, #add_offense, autocorrect_incompatible_with, badge, #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, 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?, #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