Use requires_gem to focus on rack >= 3.1.0

Author: tuxagon

lib/rubocop/cop/rails/unprocessable_content_status.rb

@@ -18,6 +18,8 @@ module Rails
       class UnprocessableContentStatus < Base
         extend AutoCorrector
 
+        requires_gem 'rack', '>= 3.1.0'
+
         MSG = 'Use `:unprocessable_content` instead of `:unprocessable_entity`. ' \
               'The `:unprocessable_entity` status is deprecated.'
 
@@ -30,8 +32,6 @@ class UnprocessableContentStatus < Base
         PATTERN
 
         def on_sym(node)
-          return unless rack_3_1_or_newer?
-
           return unless unprocessable_entity_symbol?(node)
           return if in_hash_key_context?(node)
 
@@ -43,8 +43,6 @@ def on_sym(node)
         end
 
         def on_pair(node)
-          return unless rack_3_1_or_newer?
-
           status_argument?(node) do
             add_offense(node.value) do |corrector|
               corrector.replace(node.value, ':unprocessable_content')
@@ -54,12 +52,6 @@ def on_pair(node)
 
         private
 
-        def rack_3_1_or_newer?
-          Gem::Version.new(Rack::VERSION) >= Gem::Version.new('3.1.0')
-        rescue ArgumentError, NoMethodError
-          false
-        end
-
         def in_hash_key_context?(node)
           node.parent&.pair_type? && node.parent.key == node
         end

spec/rubocop/cop/rails/unprocessable_content_status_spec.rb

@@ -1,10 +1,8 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::UnprocessableContentStatus, :config do
-  context 'when Rack is older than 3.1 or not available' do
-    before do
-      allow(cop).to receive(:rack_3_1_or_newer?).and_return(false)
-    end
+  context 'when Rack is older than 3.1' do
+    let(:gem_versions) { { 'rack' => '3.0.0' } }
 
     it 'does nothing' do
       expect_no_offenses(<<~RUBY)
@@ -14,9 +12,7 @@
   end
 
   context 'when Rack is 3.1 or later' do
-    before do
-      allow(cop).to receive(:rack_3_1_or_newer?).and_return(true)
-    end
+    let(:gem_versions) { { 'rack' => '3.1.0' } }
 
     it 'registers an offense when using :unprocessable_entity in hash argument' do
       expect_offense(<<~RUBY)