Broken digest when recording json that includes non-required special characters

[scbedd]

The java folks have a super fun situation on their hands. @lmolkova is transitioning the container registry tests to the test proxy.

Sameeksha's original thought is that as part of this test, json is sent to the service with some content that looks something like this:

// headers include a digest:
//  digest: <hash of body + other stuff>
// body is json:
{
    "key": "\/hello"
}

Which, when deserialized, sanitized, and reserialized, has a unnecessary backslash disappear and becomes

{
  "key": "/hello"
}

Such that when we run in playback, the digest now doesn't align. Included in the original context of this issue was a stack overflow that highlights why this may be occurring for this service 👍

We need to come up with a resolution for this situation.

Repro

1. Check out this branch
2. mvn install -f .\sdk\containerregistry\azure-containers-containerregistry\pom.xml "-Dcodesnippet.skip" "-Drevapi.skip" "-Dspotbugs.skip" -DskipTests=true "-Djacoco.skip" "-Dmaven.javadoc.skip=true" -DskipTestCompile "-Dcheckstyle.skip=true"
3. mvn surefire:test -f .\sdk\containerregistry\azure-containers-containerregistry\pom.xml "-Dcodesnippet.skip" "-Drevapi.skip" "-Dspotbugs.skip" "-Djacoco.skip" "-Dmaven.javadoc.skip=true" -DskipTestCompile "-Dcheckstyle.skip=true" "-Dtest=ContainerRegistryContentClientIntegrationTests#getManifestListManifest"

CC @samvaity for FYI

[scbedd]

Dug further into the live vs playback provided by @samvaity

It's not a case of \/ being disappeared, it's \\/. I think we are handling this incorrectly, but I don't know why we haven't seen anything like this in the past.

[scbedd]

This is why the double escape is disappearing.

Have some reading to do, as swapping this value to JavaScriptEncoder.Default (which is stricter about what stuff actually gets serialized) isn't a magic bullet.

[scbedd]

I have addressed this in #8430 and #8325 .

It will require a re-record of the tests that have this issue and are currently marked as live only. Executing on that today.