Enable `Style/RedundantBegin` cop to avoid newly adding redundant begin block

Currently we sometimes find a redundant begin block in code review
(e.g. https://github.com/rails/rails/pull/33604#discussion_r209784205).

I'd like to enable `Style/RedundantBegin` cop to avoid that, since
rescue/else/ensure are allowed inside do/end blocks in Ruby 2.5
(https://bugs.ruby-lang.org/issues/12906), so we'd probably meets with
that situation than before.

1 files changed, 11 insertions, 17 deletions

diff --git a/activestorage/lib/active_storage/service/disk_service.rb b/activestorage/lib/active_storage/service/disk_service.rb
index 2588c41760..67892d43b2 100644
--- a/activestorage/lib/active_storage/service/disk_service.rb
+++ b/activestorage/lib/active_storage/service/disk_service.rb
@@ -29,35 +29,29 @@ module ActiveStorage
         end
       else
         instrument :download, key: key do
-          begin
-            File.binread path_for(key)
-          rescue Errno::ENOENT
-            raise ActiveStorage::FileNotFoundError
-          end
+          File.binread path_for(key)
+        rescue Errno::ENOENT
+          raise ActiveStorage::FileNotFoundError
         end
       end
     end
 
     def download_chunk(key, range)
       instrument :download_chunk, key: key, range: range do
-        begin
-          File.open(path_for(key), "rb") do |file|
-            file.seek range.begin
-            file.read range.size
-          end
-        rescue Errno::ENOENT
-          raise ActiveStorage::FileNotFoundError
+        File.open(path_for(key), "rb") do |file|
+          file.seek range.begin
+          file.read range.size
         end
+      rescue Errno::ENOENT
+        raise ActiveStorage::FileNotFoundError
       end
     end
 
     def delete(key)
       instrument :delete, key: key do
-        begin
-          File.delete path_for(key)
-        rescue Errno::ENOENT
-          # Ignore files already deleted
-        end
+        File.delete path_for(key)
+      rescue Errno::ENOENT
+        # Ignore files already deleted
       end
     end