Fix streaming downloads from S3/Azure Storage

Closes #31073.

activestorage/lib/active_storage/service/azure_storage_service.rb

@@ -28,7 +28,7 @@ def upload(key, io, checksum: nil)
       end
     end
 
-    def download(key)
+    def download(key, &block)
       if block_given?
         instrument :streaming_download, key do
           stream(key, &block)
@@ -108,15 +108,15 @@ def format_expiry(expires_in)
       end
 
       # Reads the object for the given key in chunks, yielding each to the block.
-      def stream(key, options = {}, &block)
+      def stream(key)
         blob = blob_for(key)
 
         chunk_size = 5.megabytes
         offset = 0
 
         while offset < blob.properties[:content_length]
-          _, io = blobs.get_blob(container, key, start_range: offset, end_range: offset + chunk_size - 1)
-          yield io
+          _, chunk = blobs.get_blob(container, key, start_range: offset, end_range: offset + chunk_size - 1)
+          yield chunk.force_encoding(Encoding::BINARY)
           offset += chunk_size
         end
       end

activestorage/lib/active_storage/service/s3_service.rb

@@ -26,7 +26,7 @@ def upload(key, io, checksum: nil)
       end
     end
 
-    def download(key)
+    def download(key, &block)
       if block_given?
         instrument :streaming_download, key do
           stream(key, &block)
@@ -85,14 +85,14 @@ def object_for(key)
       end
 
       # Reads the object for the given key in chunks, yielding each to the block.
-      def stream(key, options = {}, &block)
+      def stream(key, &block)
         object = object_for(key)
 
         chunk_size = 5.megabytes
         offset = 0
 
         while offset < object.content_length
-          yield object.read(options.merge(range: "bytes=#{offset}-#{offset + chunk_size - 1}"))
+          yield object.get(range: "bytes=#{offset}-#{offset + chunk_size - 1}").body.read.force_encoding(Encoding::BINARY)
           offset += chunk_size
         end
       end

activestorage/test/service/shared_service_tests.rb

@@ -50,6 +50,16 @@ module ActiveStorage::Service::SharedServiceTests
       assert_equal FIXTURE_DATA, @service.download(FIXTURE_KEY)
     end
 
+    test "downloading in chunks" do
+      chunks = []
+
+      @service.download(FIXTURE_KEY) do |chunk|
+        chunks << chunk
+      end
+
+      assert_equal [ FIXTURE_DATA ], chunks
+    end
+
     test "existing" do
       assert @service.exist?(FIXTURE_KEY)
       assert_not @service.exist?(FIXTURE_KEY + "nonsense")