Convert a raw estree to an esast tree.
npm install --save esast/esast-from-json
# or:
bower install --save esast/esast-from-json
import {parse} from 'acorn'
import Node from 'esast/lib/ast'
import fromJson from 'esast-from-json/from-json'
const src = '1 + 1'
const ast: Node = fromJson(parse(src))