Keep track of esprima.js and escodegen.js

[jiangphcn]

Summary

esprima.js and escodegen.js are introduced to support spidermonkey 6.0 porting in CouchDB, especially supporting the traditional CouchDB-style function declaration.

"map": "function(doc) {emit(doc._id, doc._id);}"

They are being maintained under [1] https://github.com/jquery/esprima and [2] https://github.com/estools/escodegen

In planned CouchDB 3.0, we are using the variant from [3] https://github.com/dmunch/couch-chakra.

Desired Behaviour

We need to better keep track of evolution of esprima and escodegen.

Possible Solution

• create couch-esprima and couch-escodegen repositories so that there are safe copy
• compare the difference between [1] [2] and [3]
• find tools/scripts build workable version from couch-esprima and couch-escodegen
• figure out the way how to apply patch for CouchDB 3.0
• define and implement how to continuously apply fixes and improvement from [1] and [2] for CouchDB.

Additional context

@janl @garrensmith @davisp @wohali

[wohali]

@jiangphcn Any chance of working on this one? I don't want to let this get forgotten.

[jiangphcn]

thanks @wohali for checking out. I will follow up in coming days.