Rename #version_exists? to #version_active?, to reduce confusion

Closes #1926
Refs. #1926 (comment)

lib/carrierwave/uploader/versions.rb

@@ -196,9 +196,9 @@ def version_name
       #
       # === Returns
       #
-      # [Boolean] True when the version exists according to its :if or :unless condition
+      # [Boolean] True when the version satisfy its :if or :unless condition
       #
-      def version_exists?(name)
+      def version_active?(name)
         name = name.to_sym
 
         return false unless versions.has_key?(name)
@@ -222,6 +222,8 @@ def version_exists?(name)
           true
         end
       end
+      alias_method :version_exists?, :version_active?
+      CarrierWave.deprecator.deprecate_methods(self, version_exists?: :version_active?)
 
       ##
       # Copies the parent's cache_id when caching a version file.
@@ -299,7 +301,7 @@ def descendant_version_names
 
       def active_versions
         versions.select do |name, uploader|
-          version_exists?(name)
+          version_active?(name)
         end
       end
 

spec/uploader/versions_spec.rb

@@ -773,6 +773,32 @@ def shorten
         end
       end
     end
+
+    describe '#version_active?' do
+      before do
+        @file = File.open(file_path('test.jpg'))
+        @uploader_class.version(:preview, if: :true?)
+      end
+
+      it 'returns true when active' do
+        expect(@uploader).to receive(:true?).at_least(:once).and_return(true)
+        @uploader.store!(@file)
+        expect(@uploader.version_active?(:preview)).to be true
+      end
+
+      it 'returns false when inactive' do
+        expect(@uploader).to receive(:true?).at_least(:once).and_return(false)
+        @uploader.store!(@file)
+        expect(@uploader.version_active?(:preview)).to be false
+      end
+    end
+
+    describe '#version_exists' do
+      it 'shows deprecation' do
+        expect(CarrierWave.deprecator).to receive(:warn).with(/use version_active\? instead/, any_args)
+        @uploader.version_exists?(:preview)
+      end
+    end
   end
 
   describe 'with a version with option :from_version' do