Move reformat_styles to initializer, it's the only place where it is used

config/initializers/spree.rb

@@ -18,6 +18,25 @@ Spree::Gateway.class_eval do
   acts_as_taggable
 end
 
+# Spree stores attachent definitions in JSON. This converts the style name and format to
+# strings. However, when paperclip encounters these, it doesn't recognise the format.
+# Here we solve that problem by converting format and style name to symbols.
+#
+# eg. {'mini' => ['48x48>', 'png']} is converted to {mini: ['48x48>', :png]}
+def format_styles(styles)
+  styles_a = styles.map do |name, style|
+    style[1] = style[1].to_sym if style.is_a? Array
+    [name.to_sym, style]
+  end
+
+  Hash[styles_a]
+end
+
+def reformat_styles
+  Spree::Image.attachment_definitions[:attachment][:styles] =
+    format_styles(Spree::Image.attachment_definitions[:attachment][:styles])
+end
+
 Spree.config do |config|
   config.shipping_instructions = true
   config.address_requires_state = true
@@ -43,7 +62,7 @@ Spree.config do |config|
   config.attachment_styles = ENV['ATTACHMENT_STYLES'] if ENV['ATTACHMENT_STYLES']
   config.attachment_default_style = ENV['ATTACHMENT_DEFAULT_STYLE'] if ENV['ATTACHMENT_DEFAULT_STYLE']
 
-  # update_paperclip_settings
+  # Update paperclip settings
   if config.use_s3
     s3_creds = { access_key_id: config.s3_access_key,
                  secret_access_key: config.s3_secret,
@@ -65,10 +84,7 @@ Spree.config do |config|
   Spree::Image.attachment_definitions[:attachment][:default_style] =
     config.attachment_default_style
 
-  # Spree stores attachent definitions in JSON. This converts the style name and format to
-  # strings. However, when paperclip encounters these, it doesn't recognise the format.
-  # Here we solve that problem by converting format and style name to symbols.
-  Spree::Image.reformat_styles
+  reformat_styles
 end
 
 # Spree 2.0 recommends explicitly setting this here when using spree_auth_devise