8 files changed, 71 insertions, 32 deletions
diff --git a/activestorage/README.md b/activestorage/README.md
index aad11325e3..957adc05c3 100644
--- a/activestorage/README.md
+++ b/activestorage/README.md
@@ -80,7 +80,7 @@ Variation of image attachment:
 
 ```erb
 <%# Hitting the variant URL will lazy transform the original blob and then redirect to its new service location %>
-<%= image_tag url_for(user.avatar.variant(resize: "100x100")) %>
+<%= image_tag user.avatar.variant(resize: "100x100") %>
 ```
 
 ## Installation
diff --git a/activestorage/lib/active_storage/migration.rb b/activestorage/db/migrate/20170806125915_create_active_storage_tables.rb
index 2e35e163cd..6eab7e0fa0 100644
--- a/activestorage/lib/active_storage/migration.rb
+++ b/activestorage/db/migrate/20170806125915_create_active_storage_tables.rb
@@ -1,4 +1,4 @@
-class ActiveStorageCreateTables < ActiveRecord::Migration[5.1]
+class CreateActiveStorageTables < ActiveRecord::Migration[5.1]
   def change
     create_table :active_storage_blobs do |t|
       t.string   :key
diff --git a/activestorage/lib/active_storage/engine.rb b/activestorage/lib/active_storage/engine.rb
index da83d3908a..d5bc70fc0c 100644
--- a/activestorage/lib/active_storage/engine.rb
+++ b/activestorage/lib/active_storage/engine.rb
@@ -34,22 +34,21 @@ module ActiveStorage
     end
 
     initializer "active_storage.services" do
-      config.after_initialize do |app|
-        if config_choice = app.config.active_storage.service
-          config_file = Pathname.new(Rails.root.join("config/storage.yml"))
-          raise("Couldn't find Active Storage configuration in #{config_file}") unless config_file.exist?
-
-          require "yaml"
-          require "erb"
-
-          configs =
-            begin
-              YAML.load(ERB.new(config_file.read).result) || {}
-            rescue Psych::SyntaxError => e
-              raise "YAML syntax error occurred while parsing #{config_file}. " \
-                    "Please note that YAML must be consistently indented using spaces. Tabs are not allowed. " \
-                    "Error: #{e.message}"
-            end
+      config.to_prepare do
+        if config_choice = Rails.configuration.active_storage.service
+          configs = Rails.configuration.active_storage.service_configurations ||= begin
+            config_file = Pathname.new(Rails.root.join("config/storage.yml"))
+            raise("Couldn't find Active Storage configuration in #{config_file}") unless config_file.exist?
+
+            require "yaml"
+            require "erb"
+
+            YAML.load(ERB.new(config_file.read).result) || {}
+          rescue Psych::SyntaxError => e
+            raise "YAML syntax error occurred while parsing #{config_file}. " \
+                  "Please note that YAML must be consistently indented using spaces. Tabs are not allowed. " \
+                  "Error: #{e.message}"
+          end
 
           ActiveStorage::Blob.service =
             begin
diff --git a/activestorage/lib/active_storage/service/azure_storage_service.rb b/activestorage/lib/active_storage/service/azure_storage_service.rb
index c2e1b25a43..2e0b20cce3 100644
--- a/activestorage/lib/active_storage/service/azure_storage_service.rb
+++ b/activestorage/lib/active_storage/service/azure_storage_service.rb
@@ -57,11 +57,12 @@ module ActiveStorage
       end
     end
 
-    def url(key, expires_in:, disposition:, filename:)
+    def url(key, expires_in:, disposition:, filename:, content_type:)
       instrument :url, key do |payload|
         base_url = url_for(key)
         generated_url = signer.signed_uri(URI(base_url), false, permissions: "r",
-          expiry: format_expiry(expires_in), content_disposition: "#{disposition}; filename=\"#{filename}\"").to_s
+          expiry: format_expiry(expires_in), content_type: content_type,
+          content_disposition: "#{disposition}; filename=\"#{filename}\"").to_s
 
         payload[:url] = generated_url
 
diff --git a/activestorage/lib/tasks/activestorage.rake b/activestorage/lib/tasks/activestorage.rake
index 1d386e67df..d9e240b141 100644
--- a/activestorage/lib/tasks/activestorage.rake
+++ b/activestorage/lib/tasks/activestorage.rake
@@ -1,13 +1,6 @@
-require "fileutils"
-
 namespace :activestorage do
   desc "Copy over the migration needed to the application"
-  task :install do
-    migration_file_path = "db/migrate/#{Time.now.utc.strftime("%Y%m%d%H%M%S")}_active_storage_create_tables.rb"
-    FileUtils.mkdir_p Rails.root.join("db/migrate")
-    FileUtils.cp File.expand_path("../../active_storage/migration.rb", __FILE__), Rails.root.join(migration_file_path)
-    puts "Copied migration to #{migration_file_path}"
-
-    puts "Now run rails db:migrate to create the tables for Active Storage"
+  task install: :environment do
+    Rake::Task["active_storage_engine:install:migrations"].invoke
   end
 end
diff --git a/activestorage/test/database/setup.rb b/activestorage/test/database/setup.rb
index b12038ee68..610b927cc3 100644
--- a/activestorage/test/database/setup.rb
+++ b/activestorage/test/database/setup.rb
@@ -1,6 +1,5 @@
-require "active_storage/migration"
 require_relative "create_users_migration"
 
 ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
-ActiveStorageCreateTables.migrate(:up)
+ActiveRecord::Migrator.migrate File.expand_path("../../../db/migrate", __FILE__)
 ActiveStorageCreateUsers.migrate(:up)
diff --git a/activestorage/test/service/azure_storage_service_test.rb b/activestorage/test/service/azure_storage_service_test.rb
index e2be510b60..a0c6a4de73 100644
--- a/activestorage/test/service/azure_storage_service_test.rb
+++ b/activestorage/test/service/azure_storage_service_test.rb
@@ -6,8 +6,15 @@ if SERVICE_CONFIGURATIONS[:azure]
     SERVICE = ActiveStorage::Service.configure(:azure, SERVICE_CONFIGURATIONS)
 
     include ActiveStorage::Service::SharedServiceTests
-  end
 
+    test "signed URL generation" do
+      url = @service.url(FIXTURE_KEY, expires_in: 5.minutes,
+        disposition: :inline, filename: "avatar.png", content_type: "image/png")
+
+      assert_match(/(\S+)&rsct=image%2Fpng&rscd=inline%3B\+filename%3D%22avatar.png/, url)
+      assert_match SERVICE_CONFIGURATIONS[:azure][:container], url
+    end
+  end
 else
   puts "Skipping Azure Storage Service tests because no Azure configuration was supplied"
 end
diff --git a/activestorage/test/template/image_tag_test.rb b/activestorage/test/template/image_tag_test.rb
new file mode 100644
index 0000000000..83c95c01a1
--- /dev/null
+++ b/activestorage/test/template/image_tag_test.rb
@@ -0,0 +1,40 @@
+require "test_helper"
+require "database/setup"
+
+class User < ActiveRecord::Base
+  has_one_attached :avatar
+end
+
+class ActiveStorage::ImageTagTest < ActionView::TestCase
+  tests ActionView::Helpers::AssetTagHelper
+
+  setup do
+    @blob = create_image_blob filename: "racecar.jpg"
+  end
+
+  test "blob" do
+    assert_dom_equal %(<img alt="Racecar" src="#{polymorphic_url @blob}" />), image_tag(@blob)
+  end
+
+  test "variant" do
+    variant = @blob.variant(resize: "100x100")
+    assert_dom_equal %(<img alt="Racecar" src="#{polymorphic_url variant}" />), image_tag(variant)
+  end
+
+  test "attachment" do
+    attachment = ActiveStorage::Attachment.new(blob: @blob)
+    assert_dom_equal %(<img alt="Racecar" src="#{polymorphic_url attachment}" />), image_tag(attachment)
+  end
+
+  test "error when attachment's empty" do
+    @user = User.create!(name: "DHH")
+
+    assert_not @user.avatar.attached?
+    assert_raises(ArgumentError) { image_tag(@user.avatar) }
+  end
+
+  test "error when object can't be resolved into url" do
+    unresolvable_object = ActionView::Helpers::AssetTagHelper
+    assert_raises(ArgumentError) { image_tag(unresolvable_object) }
+  end
+end