[Fix rubocop#7537] Fix a false positive for `Layout/SpaceAroundOperat…

…ors`

Fixes rubocop#7537.

This PR fixes a false positive for `Layout/SpaceAroundOperators` when
using a Rational literal with `/` (e.g. `2/3r`).

CHANGELOG.md

@@ -9,6 +9,7 @@
 * [#7534](https://github.com/rubocop-hq/rubocop/issues/7534): Fix an incorrect autocorrect for `Style/BlockDelimiters` cop and `Layout/SpaceBeforeBlockBraces` cop with `EnforcedStyle: no_space` when using multiline braces. ([@koic][])
 * [#7231](https://github.com/rubocop-hq/rubocop/issues/7231): Fix the exit code to be `2` rather when `0` when the config file contains an unknown cop. ([@jethroo][])
 * [#7513](https://github.com/rubocop-hq/rubocop/issues/7513): Fix abrupt error on autocorrecting with `--disable-uncorrectable`. ([@tejasbubane][])
+* [#7537](https://github.com/rubocop-hq/rubocop/issues/7537): Fix a false positive for `Layout/SpaceAroundOperators` when using a Rational literal with `/` (e.g. `2/3r`). ([@koic][])
 
 ## 0.77.0 (2019-11-27)
 

lib/rubocop.rb

@@ -142,6 +142,7 @@
 require_relative 'rubocop/cop/mixin/percent_literal'
 require_relative 'rubocop/cop/mixin/preceding_following_alignment'
 require_relative 'rubocop/cop/mixin/preferred_delimiters'
+require_relative 'rubocop/cop/mixin/rational_literal'
 require_relative 'rubocop/cop/mixin/rescue_node'
 require_relative 'rubocop/cop/mixin/safe_assignment'
 require_relative 'rubocop/cop/mixin/space_after_punctuation'

lib/rubocop/cop/layout/space_around_operators.rb

@@ -21,6 +21,7 @@ module Layout
       class SpaceAroundOperators < Cop
         include PrecedingFollowingAlignment
         include RangeHelp
+        include RationalLiteral
 
         IRREGULAR_METHODS = %i[[] ! []=].freeze
         EXCESSIVE_SPACE = '  '
@@ -53,6 +54,8 @@ def on_resbody(node)
         end
 
         def on_send(node)
+          return if rational_literal?(node)
+
           if node.setter_method?
             on_special_asgn(node)
           elsif regular_operator?(node)

lib/rubocop/cop/mixin/rational_literal.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    # Common functionality for handling Rational literals.
+    module RationalLiteral
+      extend NodePattern::Macros
+
+      private
+
+      def_node_matcher :rational_literal?, <<~PATTERN
+        (send
+          (int _) :/
+          (rational _))
+      PATTERN
+    end
+  end
+end

spec/rubocop/cop/layout/space_around_operators_spec.rb

@@ -28,6 +28,10 @@
     expect_no_offenses('a, b = (1..2), (1...3)')
   end
 
+  it 'accepts rational' do
+    expect_no_offenses('x = 2/3r')
+  end
+
   it 'accepts scope operator' do
     expect_no_offenses('@io.class == Zlib::GzipWriter')
   end