Network access - use CORS proxy to access NPM registry

[deathcap]

webnpm needs some way to access the network if it ever hopes to be useful.

Use a CORS proxy https://www.npmjs.com/package/corsproxy? XMLHttpRequest, also see https://fetch.spec.whatwg.org

[deathcap]

The failure (after fixes in GH-2) without a CORS proxy is:

npm.commands.install(['ucfirst'])
bundle.js:76 npm command require /node_modules/npm/lib/install.js
undefined
bundle.js:439 Refused to set unsafe header "accept-encoding"
bundle.js:439 Refused to set unsafe header "referer"
bundle.js:439 Refused to set unsafe header "user-agent"
bundle.js:93897 Uncaught TypeError: undefined is not a function
bundle.js:427 OPTIONS https://registry.npmjs.org/ucfirst
localhost/:1 XMLHttpRequest cannot load https://registry.npmjs.org/ucfirst. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:9966' is therefore not allowed access. The response had HTTP status code 404.

with a CORS proxy (run sudo npm install -g corsproxy ; corsproxy locally for now), running into more problems with browser-request:

  req.on("error", cb)
  req.on("socket", function (s) {
    s.on("error", cb)
  })

The returned req is an XMLHttpRequest, and it is not an EventEmitter so it doesn't have the on property (it does have onerror, from the XHR spec). Missing compatibility in browser-request, which https://github.com/iriscouch/browser-request was last published a year ago (correction: 3 months, wrong repo in package.json? https://github.com/jhs/browser-request) , and has many open pull requests - no longer maintained? Either way, might be better to develop a more generic network request proxy (tunnel the requests over, e.g., web sockets) instead of request -> browser-request -> corsproxy