Guard against invariable file types

Australian production had one JPG image which was not recognised as
such. The `content_type` was missing and trying to generate a URL for a
variant raised an error and crashed the page.

Testing for `variable?` includes testing for `attached?` and is more
defensive.

app/models/enterprise.rb

@@ -277,7 +277,7 @@ class Enterprise < ApplicationRecord
   end
 
   def logo_url(name)
-    return unless logo.attached?
+    return unless logo.variable?
 
     Rails.application.routes.url_helpers.url_for(
       logo.variant(LOGO_SIZES[name])
@@ -285,7 +285,7 @@ class Enterprise < ApplicationRecord
   end
 
   def promo_image_url(name)
-    return unless promo_image.attached?
+    return unless promo_image.variable?
 
     Rails.application.routes.url_helpers.url_for(
       promo_image.variant(PROMO_IMAGE_SIZES[name])

app/serializers/api/admin/enterprise_serializer.rb

@@ -89,7 +89,7 @@ module Api
       #     medium: LOGO_MEDIUM_URL
       #   }
       def attachment_urls(attachment, styles)
-        return unless attachment.attached?
+        return unless attachment.variable?
 
         styles.transform_values do |transformation|
           Rails.application.routes.url_helpers.

app/views/groups/show.html.haml

@@ -22,10 +22,10 @@
     %header
       .row
         .small-12.columns
-          = image_tag @group.promo_image.variant(resize_to_limit: [1200, 260]) if @group.promo_image.attached?
+          = image_tag @group.promo_image.variant(resize_to_limit: [1200, 260]) if @group.promo_image.variable?
       .row
         .small-12.columns.group-header.pad-top
-          - if @group.logo.attached?
+          - if @group.logo.variable?
             = image_tag @group.logo.variant(resize_to_limit: [100, 100]), class: "group-logo"
           - else
             = image_tag "/noimage/group.png", class: "group-logo"

app/views/shopping_shared/_header.html.haml

@@ -4,7 +4,7 @@
   %distributor.details.row
     .small-12.medium-12.large-8.columns
       #distributor_title
-        - if distributor.logo.attached?
+        - if distributor.logo.variable?
           = image_tag distributor.logo_url(:thumb), class: "left"
         = render DistributorTitleComponent.new(name: distributor.name)
         %location= distributor.address.city

app/views/spree/admin/orders/invoice2.html.haml

@@ -6,7 +6,7 @@
       %td{ :align => "left" }
         %h4
           = t :tax_invoice
-      - if @order.distributor.display_invoice_logo? && @order.distributor.logo.attached?
+      - if @order.distributor.display_invoice_logo? && @order.distributor.logo.variable?
         %td{ :align => "right", rowspan: 2 }
           = wicked_pdf_image_tag @order.distributor.logo.variant(resize_to_limit: [150, 150])
     %tr{ valign: "top" }

app/views/spree/order_mailer/cancel_email.html.haml

@@ -6,7 +6,7 @@
           = t(".customer_greeting", name: @order.bill_address.firstname)
         %h4
           = t(".instructions_html", distributor: @order.distributor.name )
-        - if @order.distributor.logo.attached?
+        - if @order.distributor.logo.variable?
           = image_tag @order.distributor.logo_url(:medium)
 
 %p.callout

app/views/spree/order_mailer/confirm_email_for_customer.html.haml

@@ -11,7 +11,7 @@
       %table.column{:align => "left"}
         %tr
           %td{:align => "right"}
-            - if @order.distributor.logo.attached?
+            - if @order.distributor.logo.variable?
               = image_tag @order.distributor.logo_url(:medium), class: "float-right"
       %span.clear
 

app/views/spree/order_mailer/confirm_email_for_shop.html.haml

@@ -11,7 +11,7 @@
       %table.column{:align => "left"}
         %tr
           %td{:align => "right"}
-            - if @order.distributor.logo.attached?
+            - if @order.distributor.logo.variable?
               = image_tag @order.distributor.logo_url(:medium), class: "float-right"
       %span.clear
 

app/views/subscription_mailer/_header.html.haml

@@ -11,6 +11,6 @@
       %table.column{:align => "left"}
         %tr
           %td{:align => "right"}
-            - if @order.distributor.logo.attached?
+            - if @order.distributor.logo.variable?
               = image_tag @order.distributor.logo_url(:medium), class: "float-right"
       %span.clear

app/views/subscription_mailer/confirmation_summary_email.html.haml

@@ -11,7 +11,7 @@
       %table.column{:align => "left"}
         %tr
           %td{:align => "right"}
-            - if @shop.logo.attached?
+            - if @shop.logo.variable?
               = image_tag @shop.logo_url(:medium), class: "float-right"
       %span.clear
 

app/views/subscription_mailer/placement_summary_email.html.haml

@@ -11,7 +11,7 @@
       %table.column{:align => "left"}
         %tr
           %td{:align => "right"}
-            - if @shop.logo.attached?
+            - if @shop.logo.variable?
               = image_tag @shop.logo_variant(:medium), class: "float-right"
       %span.clear