Error JSON-object decoding based on HTTP Status Code

[tasanobu-zz]

Currently there are some cases that error objects in JSON format are not properly decoded.

__type is assigned to the raw value of CodingKeys.type at here for JSON content payload, and it works fine in case that an error code is set to __type field in JSON object. (e.g. DynamoDB)
However, there are some services (e.g. rds-data, api-gateway) where error code is decided based on HTTP Status Code. Generated code for such services does not work.

Example case

rds-data returns an error JSON object like below.

{"message":"Unknown database 'non-existing-database'"}

The error JSON decoding fails and the error below is raised because there is no __type field.

keyNotFound(CodingKeys(stringValue: "__type", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with key CodingKeys(stringValue: \"__type\", intValue: nil) (\"__type\").", underlyingError: nil))

Question

I'm wondering if it would be possible to solve this issue by passing a specific delegate name to HttpClientConfiguration.clientDelegateNameOverride in a configuration (e.g. RDSConfiguration.swift). That delegate name is used in ModelClientDelegate. addJsonDelegate instead of JSONAWSHttpClientDelegate.

The questions are

• where the delegate struct should be implemented? (maybe, in smoke-aws)
• If the delegate struct is implemented correctly at a right place, would the solution above work? (as long as the delegate struct decides error based on HTTP Status Code.)