Jsoncycles

[ariel-bentu]

fixes #5121 - circular references in JSON in RPC traffic

It uses modified code (converted to typescript) from https://raw.githubusercontent.com/douglascrockford/JSON-js/master/cycle.js

It detects circular references while stringifying JSON, and converts to to a text reference. later after parse, it can restore the right reference.

This was important to support https://github.com/mtxr/vscode-sqltools run in Theia.

[vince-fugnitto]

@ariel-bentu unfortunately, there are a few problems with the PR before we can continue with a review.

It looks like during the amend, the PR got a little messed up, can you make sure that the PR only has one commit (your original commit).

Also, since you copied code, we will first need to make sure the original license is compatible with our project, and that we register a CQ for the copied code.

There are also build errors picked up by the CI, can you resolve them?

[ariel-bentu]

No problem, it is still not ready apparently. But as I make it ready, I would like feedback on the idea, to use douglas crockford's cycle.js code, which remove the cycle, but also can recreate them after json.parse. it comes with some price - it clones most of the object before stringify, and also maintains a WeakMap of all objects and arrays in the strigify-ed object while removing the cycles - which has some transient memory impact. If we wish to seamlessly support cycled object - I guess this is the way. So if you feel this is right - I will proceed with making it complete.
Thanks