Response not written to file when using :response_target with stubbed_responses: true

[ghost]

Issue description

When I use stub_responses: true when creating a client for S3, I expect the behavior
of response_target options to be the same as a client without this option.

Expected behavior

If a response is stubbed, it is still a response and I would assert that code relying on the response body
to be written to a file should work whether the s3 client is stubbed or not.

Current behavior

When the client has stub_responses: true the file is never written to disk.

Gem name

aws-sdk-s3 (1.20.0)

Version of Ruby, OS environment

macOS High Sierra 10.13.6, ruby-2.5.1

Code snippets / steps to reproduce

[andrew.newell@C02N5BBFG3QD aws_sdk_testing ]$ irb   

2.5.1 :001 > require 'aws-sdk-s3'
 => true 
2.5.1 :002 > @s3_client = Aws::S3::Client.new(stub_responses: true)
 => #<Aws::S3::Client> 
2.5.1 :003 > data = @s3_client.stub_data(:get_object, body: 'this is a body')
 => #<struct Aws::S3::Types::GetObjectOutput body="this is a body", delete_marker=false, accept_ranges="AcceptRanges", expiration="Expiration", restore="Restore", last_modified=2018-09-25 13:27:31 -0400, content_length=0, etag="ETag", missing_meta=0, version_id="ObjectVersionId", cache_control="CacheControl", content_disposition="ContentDisposition", content_encoding="ContentEncoding", content_language="ContentLanguage", content_range="ContentRange", content_type="ContentType", expires=2018-09-25 13:27:31 -0400, expires_string="ExpiresString", website_redirect_location="WebsiteRedirectLocation", server_side_encryption="ServerSideEncryption", metadata={}, sse_customer_algorithm="SSECustomerAlgorithm", sse_customer_key_md5="SSECustomerKeyMD5", ssekms_key_id="SSEKMSKeyId", storage_class="StorageClass", request_charged="RequestCharged", replication_status="ReplicationStatus", parts_count=0, tag_count=0> 
2.5.1 :004 > @s3_client.stub_responses(:get_object, data)
 => [{:data=>#<struct Aws::S3::Types::GetObjectOutput body="this is a body", delete_marker=false, accept_ranges="AcceptRanges", expiration="Expiration", restore="Restore", last_modified=2018-09-25 13:27:31 -0400, content_length=0, etag="ETag", missing_meta=0, version_id="ObjectVersionId", cache_control="CacheControl", content_disposition="ContentDisposition", content_encoding="ContentEncoding", content_language="ContentLanguage", content_range="ContentRange", content_type="ContentType", expires=2018-09-25 13:27:31 -0400, expires_string="ExpiresString", website_redirect_location="WebsiteRedirectLocation", server_side_encryption="ServerSideEncryption", metadata={}, sse_customer_algorithm="SSECustomerAlgorithm", sse_customer_key_md5="SSECustomerKeyMD5", ssekms_key_id="SSEKMSKeyId", storage_class="StorageClass", request_charged="RequestCharged", replication_status="ReplicationStatus", parts_count=0, tag_count=0>}] 
2.5.1 :005 > @s3_client.get_object({bucket: 'bucket', key: 'key'}, response_target: '/tmp/aws_sdk_testing/output' )
 => #<struct Aws::S3::Types::GetObjectOutput body="this is a body", delete_marker=false, accept_ranges="AcceptRanges", expiration="Expiration", restore="Restore", last_modified=2018-09-25 13:27:31 -0400, content_length=0, etag="ETag", missing_meta=0, version_id="ObjectVersionId", cache_control="CacheControl", content_disposition="ContentDisposition", content_encoding="ContentEncoding", content_language="ContentLanguage", content_range="ContentRange", content_type="ContentType", expires=2018-09-25 13:27:31 -0400, expires_string="ExpiresString", website_redirect_location="WebsiteRedirectLocation", server_side_encryption="ServerSideEncryption", metadata={}, sse_customer_algorithm="SSECustomerAlgorithm", sse_customer_key_md5="SSECustomerKeyMD5", ssekms_key_id="SSEKMSKeyId", storage_class="StorageClass", request_charged="RequestCharged", replication_status="ReplicationStatus", parts_count=0, tag_count=0> 
2.5.1 :006 > exit

[andrew.newell@C02N5BBFG3QD aws_sdk_testing ]$ pwd       
/tmp/aws_sdk_testing
[andrew.newell@C02N5BBFG3QD aws_sdk_testing ]$ ls -alhF
total 0
drwxr-xr-x   2 andrew.newell  wheel    64B Sep 25 13:29 ./
drwxrwxrwt  11 root           wheel   352B Sep 25 13:26 ../
[andrew.newell@C02N5BBFG3QD aws_sdk_testing ]$ 

[ghost]

This looks like it could be related to #823 and amazon-archives/aws-sdk-core-ruby#197

[srchase]

Hello @andrew-newell,

Thanks for reporting this issue.

Both of the issues you point to are for the prior version of the SDK. Stubbing for the current version does not support writing the response_target to a file.

I'm marking this a feature request.

[ghost]

Stubbing for the current version does not support writing the response_target to a file.

@srchase Can you point me to the documentation for this behavior please?

[srchase]

@andrew-newell

Can you give this a try instead?

@s3_client = Aws::S3::Client.new(stub_responses: true)
@s3_client.stub_responses(:get_object, body: 'this is a body')
@s3_client.get_object(response_target: 'output.txt', bucket: 'myBucket', key: 'myKey')

[srchase]

You can check out this blog post by @awood45 for some additional reading on Advanced client stubbing in the AWS SDK for Ruby Version 3.

You'll likely be able to accomplish most things with stub_responses. That allows you to set the data or errors that will get returned on the normal client calls you make elsewhere.

[ghost]

@andrew-newell

Can you give this a try instead?

@s3_client = Aws::S3::Client.new(stub_responses: true)
@s3_client.stub_responses(:get_object, body: 'this is a body')
@s3_client.get_object(response_target: 'output.txt', bucket: 'myBucket', key: 'myKey')

Yep, that works. Thanks for your help.