Mirror: explicit primary service and list of mirrors

Pass separate primary service and list of mirrors rather than treating
the first of the services list as the primary. Nice fit for keyword args,
and something we've long wanted in the equivalent Basecamp file repository.

Upload returns the results of the underlying service uploads rather than
the io.rewind result. Rewind before uploading rather than afterward, and
demonstrate that behavior with a test.

Test that more than one mirror works.

1 files changed, 13 insertions, 5 deletions

diff --git a/test/service/mirror_service_test.rb b/test/service/mirror_service_test.rb
index 45535c754e..10af41c0a8 100644
--- a/test/service/mirror_service_test.rb
+++ b/test/service/mirror_service_test.rb
@@ -3,9 +3,11 @@ require "service/shared_service_tests"
 
 class ActiveStorage::Service::MirrorServiceTest < ActiveSupport::TestCase
   PRIMARY_DISK_SERVICE   = ActiveStorage::Service.configure(:Disk, root: File.join(Dir.tmpdir, "active_storage"))
-  SECONDARY_DISK_SERVICE = ActiveStorage::Service.configure(:Disk, root: File.join(Dir.tmpdir, "active_storage_mirror"))
+  MIRROR_SERVICES = (1..3).map do |i|
+    ActiveStorage::Service.configure(:Disk, root: File.join(Dir.tmpdir, "active_storage_mirror_#{i}"))
+  end
 
-  SERVICE = ActiveStorage::Service.configure :Mirror, services: [ PRIMARY_DISK_SERVICE, SECONDARY_DISK_SERVICE ]
+  SERVICE = ActiveStorage::Service.configure :Mirror, primary: PRIMARY_DISK_SERVICE, mirrors: MIRROR_SERVICES
 
   include ActiveStorage::Service::SharedServiceTests
 
@@ -15,7 +17,9 @@ class ActiveStorage::Service::MirrorServiceTest < ActiveSupport::TestCase
       key  = upload(data, to: @service)
 
       assert_equal data, PRIMARY_DISK_SERVICE.download(key)
-      assert_equal data, SECONDARY_DISK_SERVICE.download(key)
+      MIRROR_SERVICES.each do |mirror|
+        assert_equal data, mirror.download(key)
+      end
     ensure
       @service.delete key
     end
@@ -31,7 +35,9 @@ class ActiveStorage::Service::MirrorServiceTest < ActiveSupport::TestCase
   test "deleting from all services" do
     @service.delete FIXTURE_KEY
     assert_not PRIMARY_DISK_SERVICE.exist?(FIXTURE_KEY)
-    assert_not SECONDARY_DISK_SERVICE.exist?(FIXTURE_KEY)
+    MIRROR_SERVICES.each do |mirror|
+      assert_not mirror.exist?(FIXTURE_KEY)
+    end
   end
 
   test "URL generation in primary service" do
@@ -44,7 +50,9 @@ class ActiveStorage::Service::MirrorServiceTest < ActiveSupport::TestCase
   private
     def upload(data, to:)
       SecureRandom.base58(24).tap do |key|
-        @service.upload key, StringIO.new(data), checksum: Digest::MD5.base64digest(data)
+        io = StringIO.new(data).tap(&:read)
+        @service.upload key, io, checksum: Digest::MD5.base64digest(data)
+        assert io.eof?
       end
     end
 end