Fix s3 multipart uploads when threshold is larger than the file uploaded

mullermp commented 11 days ago

Summary

Hello from AWS. A customer reported a bug in our repo (aws/aws-sdk-ruby#2451) around using :multipart_threshold with ActiveStorage. The bug occurs when the file being uploaded has a smaller size than the multipart threshold. This happens because the :multipart_threshold is passed into :put_object, a parameter that is not understood by the s3 API. This results in a param validation failure. Please see the above issue for more details.

Other Information

I tested this by doing the following:

• Made a new rails app (rails new --skip-javascript)
• Set the Gemfile to use my fork with path:
• Configured ActiveStorage and S3 similar to https://edgeguides.rubyonrails.org/active_storage_overview.html
• Added multipart_threshold: <%= 10.megabytes %> under the :upload and :amazon keys.
• Attempted to upload a file that was 38 kb, resulting in a failure (customer reproduction)
• Made the code change in my fork
• Attempted the same upload and it succeeded. I verified the object in my bucket.

As far as unit tests go, I'm not sure if you wanted an explicit test for this - I would assume it's not necessary in this case because it's a matter of what parameters are passed through to the SDK.