made normalize_collection a class method & added test for it

Author: Oaphi

lib/namespaced_env_cache.rb

@@ -85,7 +85,7 @@ def write_collection(name, value, **opts)
         raise TypeError, "Can't cache more than one type of object via write_collection"
       end
 
-      data = normalize_collection(value)
+      data = NamespacedEnvCache.normalize_collection(value)
       namespaced = construct_ns_key(name, include_community: include_community(opts))
       @underlying.write(namespaced, data, **opts)
     end
@@ -102,7 +102,7 @@ def read_collection(name, **opts)
       return nil if data.nil?
 
       if data.is_a?(ActiveRecord::Relation)
-        data = normalize_collection(data)
+        data = NamespacedEnvCache.normalize_collection(data)
       end
 
       type = data.slice!(0)
@@ -136,6 +136,13 @@ def fetch_collection(name, **opts, &block)
       end
     end
 
+    # Normalizes a given ActiveRecord collection for use with the cache
+    # @param value [ActiveRecord::Relation] collection to normalize
+    # @return [Array(String, *Integer)]
+    def self.normalize_collection(value)
+      [value[0].class.to_s, *value.map(&:id)]
+    end
+
     # We have to statically report that we support cache versioning even though this depends on the underlying class.
     # However, this is not really a problem since all cache stores provided by activesupport support the feature and
     # we only use the redis cache (by activesupport) for QPixel.
@@ -150,12 +157,5 @@ def construct_ns_key(key, include_community: true)
       c_id = RequestContext.community_id if include_community
       "#{Rails.env}://#{[c_id, key].compact.join('/')}"
     end
-
-    # Normalizes a given ActiveRecord collection for use with the cache
-    # @param value [ActiveRecord::Relation] collection to normalize
-    # @return [Array(String, *Integer)]
-    def normalize_collection(value)
-      [value[0].class.to_s, *value.map(&:id)]
-    end
   end
 end

test/lib/namespaced_env_cache_test.rb

@@ -48,6 +48,13 @@ class NamespacedEnvCacheTest < ActiveSupport::TestCase
     end
   end
 
+  test 'normalize_collection should correctly prepare collections for caching' do
+    collection = Post.where(user: users(:standard_user))
+    normalized = QPixel::NamespacedEnvCache.normalize_collection(collection)
+    assert_equal Post.name, normalized.shift
+    assert(collection.to_a.all? { |post| normalized.include?(post.id) })
+  end
+
   private
 
   def new_cache_store