REST client - Response.getWarnings() does not decode escaped quotes

[markharwood]

I ran into a failing test scenario where the Java string logged server-side with the DeprecationLogger.deprecatedAndMaybeLog failed to match the same string when materialized client-side using Response. getWarnings().
The string in question had quotes eg:

public static final String DEPRECATION_MESSAGE = "Don't use \"type\" please";

which is encoded to HTTP headers by the logging framework with slashes around the quotes eg Don't use \"type\" please
When deserialized on the client the slashes are not decoded meaning our test fails because Don't use \"type\" please != Don't use "type" please

[elasticmachine]

Pinging @elastic/es-core-features

[markharwood]

I made a start on the required decoder function but have yet to figure out where to put it. DeprecationLogger felt the most natural place alongside its escapeBackslashesAndQuotes function but the HLRC build has checks to reject classes that refer to this server-side class. Makes it hard for the client-side Response object to invoke.

Either way a gist with the necessary function and test code is here: https://gist.github.com/markharwood/aa5215d0b7128c23d93904774a51e937

[jakelandis]

We discussed this briefly today in our team sync, and believe that best path forward here is to simply ensure we don't quotes inside quotes. Ideally use [] where applicable. Leaving this issue open until we are

• Confident that we got them all
• Have an assertion in DeprecationLogger.deprecatedAndMaybeLog to fail if we encounter escaped quotes

[dakrone]

This has been open for quite a while, and we haven't made much progress on this due to focus in other areas. For now I'm going to close this as something we aren't planning on implementing. We can re-open it later if needed.