inpage.js

/*global Web3*/
cleanContextForImports()
require('web3/dist/web3.min.js')
const log = require('loglevel')
const LocalMessageDuplexStream = require('post-message-stream')
const setupDappAutoReload = require('./lib/auto-reload.js')
const MetamaskInpageProvider = require('metamask-inpage-provider')
const createStandardProvider = require('./createStandardProvider').default

let warned = false

restoreContextAfterImports()

log.setDefaultLevel(process.env.METAMASK_DEBUG ? 'debug' : 'warn')

//
// setup plugin communication
//

// setup background connection
const metamaskStream = new LocalMessageDuplexStream({
  name: 'inpage_tangerine',
  target: 'contentscript_tangerine',
})

// compose the inpage provider
const inpageProvider = new MetamaskInpageProvider(metamaskStream)

// set a high max listener count to avoid unnecesary warnings
inpageProvider.setMaxListeners(100)

// augment the provider with its enable method
inpageProvider.enable = function ({ force } = {}) {
  return new Promise((resolve, reject) => {
    inpageProvider.sendAsync({ method: 'eth_requestAccounts', params: [force] }, (error, response) => {
      if (error || response.error) {
        reject(error || response.error)
      } else {
        resolve(response.result)
      }
    })
  })
}

// give the dapps control of a refresh they can toggle this off on the window.ethereum
// this will be default true so it does not break any old apps.
inpageProvider.autoRefreshOnNetworkChange = true

// add metamask-specific convenience methods
inpageProvider._metamask = new Proxy({
  /**
   * Synchronously determines if this domain is currently enabled, with a potential false negative if called to soon
   *
   * @returns {boolean} - returns true if this domain is currently enabled
   */
  isEnabled: function () {
    const { isEnabled } = inpageProvider.publicConfigStore.getState()
    return Boolean(isEnabled)
  },

  /**
   * Asynchronously determines if this domain is currently enabled
   *
   * @returns {Promise<boolean>} - Promise resolving to true if this domain is currently enabled
   */
  isApproved: async function () {
    const { isEnabled } = await getPublicConfigWhenReady()
    return Boolean(isEnabled)
  },

  /**
   * Determines if MetaMask is unlocked by the user
   *
   * @returns {Promise<boolean>} - Promise resolving to true if MetaMask is currently unlocked
   */
  isUnlocked: async function () {
    const { isUnlocked } = await getPublicConfigWhenReady()
    return Boolean(isUnlocked)
  },
}, {
  get: function (obj, prop) {
    !warned && console.warn('Heads up! ethereum._metamask exposes methods that have ' +
    'not been standardized yet. This means that these methods may not be implemented ' +
    'in other dapp browsers and may be removed from MetaMask in the future.')
    warned = true
    return obj[prop]
  },
})

// publicConfig isn't populated until we get a message from background.
// Using this getter will ensure the state is available
async function getPublicConfigWhenReady () {
  const store = inpageProvider.publicConfigStore
  let state = store.getState()
  // if state is missing, wait for first update
  if (!state.networkVersion) {
    state = await new Promise(resolve => store.once('update', resolve))
    console.log('new state', state)
  }
  return state
}

// Work around for web3@1.0 deleting the bound `sendAsync` but not the unbound
// `sendAsync` method on the prototype, causing `this` reference issues with drizzle
const proxiedInpageProvider = new Proxy(inpageProvider, {
  // straight up lie that we deleted the property so that it doesnt
  // throw an error in strict mode
  deleteProperty: () => true,
})

// window.ethereum = createStandardProvider(proxiedInpageProvider)
window.tangerine = createStandardProvider(proxiedInpageProvider)

//
// setup web3
//

const web3 = new Web3(proxiedInpageProvider)
web3.setProvider = function () {
  log.debug('MetaMask - overrode web3.setProvider')
}
log.debug('MetaMask - injected web3')

setupDappAutoReload(web3, inpageProvider.publicConfigStore)

// set web3 defaultAccount
inpageProvider.publicConfigStore.subscribe(function (state) {
  web3.eth.defaultAccount = state.selectedAddress
})

inpageProvider.publicConfigStore.subscribe(function (state) {
  if (state.onboardingcomplete) {
    window.postMessage('onboardingcomplete', '*')
  }
})

// need to make sure we aren't affected by overlapping namespaces
// and that we dont affect the app with our namespace
// mostly a fix for web3's BigNumber if AMD's "define" is defined...
let __define

/**
 * Caches reference to global define object and deletes it to
 * avoid conflicts with other global define objects, such as
 * AMD's define function
 */
function cleanContextForImports () {
  __define = global.define
  try {
    global.define = undefined
  } catch (_) {
    console.warn('MetaMask - global.define could not be deleted.')
  }
}

/**
 * Restores global define object from cached reference
 */
function restoreContextAfterImports () {
  try {
    global.define = __define
  } catch (_) {
    console.warn('MetaMask - global.define could not be overwritten.')
  }
}