web3 -- web worker environment isn't supported

[7-of-9]

Hi all,

Beta 34 (and/or its dependencies, e.g. any-promise) seems to have dependencies on "window" instead of "self" which prevents it working in a web worker context. I've not yet tested on later betas, but suspect they suffer from the same.

Related: #1774
Related: https://ethereum.stackexchange.com/questions/56405/integrating-web3-from-metamask-in-react

[nivida]

This issue got solved in the version 1.0.0-beta.38 which I will release within the next days.

[7-of-9]

@nivida fyi -- re. beta41: I'm seeing "window is not defined" when creating a new Web3.providers.WebsocketProvider(...) inside A web worker context.

(< beta38 threw much earlier: at "import Web3...", so it's closer to working!)

UPDATE: self.window = self
In web worker before new WebsockProvider() seems to fix this.

Fix at source would be line 1162 of web3-provider-umd.js (beta41) - just remove "Window."

[naturalfreak]

same problem with version 1.2.4

[timothywangdev]

still broken

[keirongulrajani]

When I've tried importScripts in a Web Worker using web3.js instead of web3.min.js from the node module i can see the window is not defined error being thrown when register-shim is being loaded; this is a file inside any-promise, and the any-promise library is used by web3-core-promievent in the current version.

The loadImplementation() inside register-shim.js is attempting to grab window.Promise when there is no window:

/**
 * Browser specific loadImplementation.  Always uses `window.Promise`
 *
 * To register a custom implementation, must register with `Promise` option.
 */
function loadImplementation(){
  if(typeof window.Promise === 'undefined'){
    throw new Error("any-promise browser requires a polyfill or explicit registration"+
      " e.g: require('any-promise/register/bluebird')")
  }
  return {
    Promise: window.Promise,
    implementation: 'window.Promise'
  }
}

perhaps doing as it says to register a custom implementation with a Promise option is the solution?

EDIT: for those experiencing this issue with the window being undefined, I found a solution here about setting window as self first before the importScripts statements so that it has the correct environment (effectively tricking any-promise under the hood while loading to treat the worker as window:

var window = self;
importScripts(/*path to web 3 goes here*/);