Move inpage-provider and port-stream outside

With the creation of the [metamask-extension-provider](https://github.com/MetaMask/metamask-extension-provider) we have our first non-core module that is dependent on the inpage-provider and port-stream.

To reduce the size of its dependencies, I have moved the
[metamask-inpage-provider](https://github.com/MetaMask/metamask-inpage-provider) into its own module, as well as [extension-port-stream](https://github.com/MetaMask/extension-port-stream).

This allows them to be more easily depended & iterated on by external
projects.

7 files changed, 4 insertions, 276 deletions

diff --git a/app/scripts/background.js b/app/scripts/background.js
index c7395c810..d4d87e0d5 100644
--- a/app/scripts/background.js
+++ b/app/scripts/background.js
@@ -15,7 +15,7 @@ const asStream = require('obs-store/lib/asStream')
 const ExtensionPlatform = require('./platforms/extension')
 const Migrator = require('./lib/migrator/')
 const migrations = require('./migrations/')
-const PortStream = require('./lib/port-stream.js')
+const PortStream = require('extension-port-stream')
 const createStreamSink = require('./lib/createStreamSink')
 const NotificationManager = require('./lib/notification-manager.js')
 const MetamaskController = require('./metamask-controller')
diff --git a/app/scripts/contentscript.js b/app/scripts/contentscript.js
index e0a2b0061..6eee1987a 100644
--- a/app/scripts/contentscript.js
+++ b/app/scripts/contentscript.js
@@ -5,7 +5,7 @@ const LocalMessageDuplexStream = require('post-message-stream')
 const PongStream = require('ping-pong-stream/pong')
 const ObjectMultiplex = require('obj-multiplex')
 const extension = require('extensionizer')
-const PortStream = require('./lib/port-stream.js')
+const PortStream = require('extension-port-stream')
 
 const inpageContent = fs.readFileSync(path.join(__dirname, '..', '..', 'dist', 'chrome', 'inpage.js')).toString()
 const inpageSuffix = '//# sourceURL=' + extension.extension.getURL('inpage.js') + '\n'
diff --git a/app/scripts/inpage.js b/app/scripts/inpage.js
index 7dd7fda02..1a170c617 100644
--- a/app/scripts/inpage.js
+++ b/app/scripts/inpage.js
@@ -4,7 +4,7 @@ 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('./lib/inpage-provider.js')
+const MetamaskInpageProvider = require('metamask-inpage-provider')
 restoreContextAfterImports()
 
 log.setDefaultLevel(process.env.METAMASK_DEBUG ? 'debug' : 'warn')
diff --git a/app/scripts/lib/createErrorMiddleware.js b/app/scripts/lib/createErrorMiddleware.js
deleted file mode 100644
index 7f6a4bd73..000000000
--- a/app/scripts/lib/createErrorMiddleware.js
+++ /dev/null
@@ -1,67 +0,0 @@
-const log = require('loglevel')
-
-/**
- * JSON-RPC error object
- *
- * @typedef {Object} RpcError
- * @property {number} code - Indicates the error type that occurred
- * @property {Object} [data] - Contains additional information about the error
- * @property {string} [message] - Short description of the error
- */
-
-/**
- * Middleware configuration object
- *
- * @typedef {Object} MiddlewareConfig
- * @property {boolean} [override] - Use RPC_ERRORS message in place of provider message
- */
-
-/**
- * Map of standard and non-standard RPC error codes to messages
- */
-const RPC_ERRORS = {
-  1: 'An unauthorized action was attempted.',
-  2: 'A disallowed action was attempted.',
-  3: 'An execution error occurred.',
-  [-32600]: 'The JSON sent is not a valid Request object.',
-  [-32601]: 'The method does not exist / is not available.',
-  [-32602]: 'Invalid method parameter(s).',
-  [-32603]: 'Internal JSON-RPC error.',
-  [-32700]: 'Invalid JSON was received by the server. An error occurred on the server while parsing the JSON text.',
-  internal: 'Internal server error.',
-  unknown: 'Unknown JSON-RPC error.',
-}
-
-/**
- * Modifies a JSON-RPC error object in-place to add a human-readable message,
- * optionally overriding any provider-supplied message
- *
- * @param {RpcError} error - JSON-RPC error object
- * @param {boolean} override - Use RPC_ERRORS message in place of provider message
- */
-function sanitizeRPCError (error, override) {
-  if (error.message && !override) { return error }
-  const message = error.code > -31099 && error.code < -32100 ? RPC_ERRORS.internal : RPC_ERRORS[error.code]
-  error.message = message || RPC_ERRORS.unknown
-}
-
-/**
- * json-rpc-engine middleware that both logs standard and non-standard error
- * messages and ends middleware stack traversal if an error is encountered
- *
- * @param {MiddlewareConfig} [config={override:true}] - Middleware configuration
- * @returns {Function} json-rpc-engine middleware function
- */
-function createErrorMiddleware ({ override = true } = {}) {
-  return (req, res, next) => {
-    next(done => {
-      const { error } = res
-      if (!error) { return done() }
-      sanitizeRPCError(error)
-      log.error(`MetaMask - RPC Error: ${error.message}`, error)
-      done()
-    })
-  }
-}
-
-module.exports = createErrorMiddleware
diff --git a/app/scripts/lib/inpage-provider.js b/app/scripts/lib/inpage-provider.js
deleted file mode 100644
index 6ef511453..000000000
--- a/app/scripts/lib/inpage-provider.js
+++ /dev/null
@@ -1,125 +0,0 @@
-const pump = require('pump')
-const RpcEngine = require('json-rpc-engine')
-const createErrorMiddleware = require('./createErrorMiddleware')
-const createIdRemapMiddleware = require('json-rpc-engine/src/idRemapMiddleware')
-const createStreamMiddleware = require('json-rpc-middleware-stream')
-const LocalStorageStore = require('obs-store')
-const asStream = require('obs-store/lib/asStream')
-const ObjectMultiplex = require('obj-multiplex')
-
-module.exports = MetamaskInpageProvider
-
-function MetamaskInpageProvider (connectionStream) {
-  const self = this
-
-  // setup connectionStream multiplexing
-  const mux = self.mux = new ObjectMultiplex()
-  pump(
-    connectionStream,
-    mux,
-    connectionStream,
-    (err) => logStreamDisconnectWarning('MetaMask', err)
-  )
-
-  // subscribe to metamask public config (one-way)
-  self.publicConfigStore = new LocalStorageStore({ storageKey: 'MetaMask-Config' })
-
-  pump(
-    mux.createStream('publicConfig'),
-    asStream(self.publicConfigStore),
-    (err) => logStreamDisconnectWarning('MetaMask PublicConfigStore', err)
-  )
-
-  // ignore phishing warning message (handled elsewhere)
-  mux.ignoreStream('phishing')
-
-  // connect to async provider
-  const streamMiddleware = createStreamMiddleware()
-  pump(
-    streamMiddleware.stream,
-    mux.createStream('provider'),
-    streamMiddleware.stream,
-    (err) => logStreamDisconnectWarning('MetaMask RpcProvider', err)
-  )
-
-  // handle sendAsync requests via dapp-side rpc engine
-  const rpcEngine = new RpcEngine()
-  rpcEngine.push(createIdRemapMiddleware())
-  rpcEngine.push(createErrorMiddleware())
-  rpcEngine.push(streamMiddleware)
-  self.rpcEngine = rpcEngine
-}
-
-// handle sendAsync requests via asyncProvider
-// also remap ids inbound and outbound
-MetamaskInpageProvider.prototype.sendAsync = function (payload, cb) {
-  const self = this
-
-  if (payload.method === 'eth_signTypedData') {
-    console.warn('MetaMask: This experimental version of eth_signTypedData will be deprecated in the next release in favor of the standard as defined in EIP-712. See https://git.io/fNzPl for more information on the new standard.')
-  }
-
-  self.rpcEngine.handle(payload, cb)
-}
-
-
-MetamaskInpageProvider.prototype.send = function (payload) {
-  const self = this
-
-  let selectedAddress
-  let result = null
-  switch (payload.method) {
-
-    case 'eth_accounts':
-      // read from localStorage
-      selectedAddress = self.publicConfigStore.getState().selectedAddress
-      result = selectedAddress ? [selectedAddress] : []
-      break
-
-    case 'eth_coinbase':
-      // read from localStorage
-      selectedAddress = self.publicConfigStore.getState().selectedAddress
-      result = selectedAddress || null
-      break
-
-    case 'eth_uninstallFilter':
-      self.sendAsync(payload, noop)
-      result = true
-      break
-
-    case 'net_version':
-      const networkVersion = self.publicConfigStore.getState().networkVersion
-      result = networkVersion || null
-      break
-
-    // throw not-supported Error
-    default:
-      var link = 'https://github.com/MetaMask/faq/blob/master/DEVELOPERS.md#dizzy-all-async---think-of-metamask-as-a-light-client'
-      var message = `The MetaMask Web3 object does not support synchronous methods like ${payload.method} without a callback parameter. See ${link} for details.`
-      throw new Error(message)
-
-  }
-
-  // return the result
-  return {
-    id: payload.id,
-    jsonrpc: payload.jsonrpc,
-    result: result,
-  }
-}
-
-MetamaskInpageProvider.prototype.isConnected = function () {
-  return true
-}
-
-MetamaskInpageProvider.prototype.isMetaMask = true
-
-// util
-
-function logStreamDisconnectWarning (remoteLabel, err) {
-  let warningMsg = `MetamaskInpageProvider - lost connection to ${remoteLabel}`
-  if (err) warningMsg += '\n' + err.stack
-  console.warn(warningMsg)
-}
-
-function noop () {}
diff --git a/app/scripts/lib/port-stream.js b/app/scripts/lib/port-stream.js
deleted file mode 100644
index fd65d94f3..000000000
--- a/app/scripts/lib/port-stream.js
+++ /dev/null
@@ -1,80 +0,0 @@
-const Duplex = require('readable-stream').Duplex
-const inherits = require('util').inherits
-const noop = function () {}
-
-module.exports = PortDuplexStream
-
-inherits(PortDuplexStream, Duplex)
-
-/**
- * Creates a stream that's both readable and writable.
- * The stream supports arbitrary objects.
- *
- * @class
- * @param {Object} port Remote Port object
- */
-function PortDuplexStream (port) {
-  Duplex.call(this, {
-    objectMode: true,
-  })
-  this._port = port
-  port.onMessage.addListener(this._onMessage.bind(this))
-  port.onDisconnect.addListener(this._onDisconnect.bind(this))
-}
-
-/**
- * Callback triggered when a message is received from
- * the remote Port associated with this Stream.
- *
- * @private
- * @param {Object} msg - Payload from the onMessage listener of Port
- */
-PortDuplexStream.prototype._onMessage = function (msg) {
-  if (Buffer.isBuffer(msg)) {
-    delete msg._isBuffer
-    var data = new Buffer(msg)
-    this.push(data)
-  } else {
-    this.push(msg)
-  }
-}
-
-/**
- * Callback triggered when the remote Port
- * associated with this Stream disconnects.
- *
- * @private
- */
-PortDuplexStream.prototype._onDisconnect = function () {
-  this.destroy()
-}
-
-/**
- * Explicitly sets read operations to a no-op
- */
-PortDuplexStream.prototype._read = noop
-
-
-/**
- * Called internally when data should be written to
- * this writable stream.
- *
- * @private
- * @param {*} msg Arbitrary object to write
- * @param {string} encoding Encoding to use when writing payload
- * @param {Function} cb Called when writing is complete or an error occurs
- */
-PortDuplexStream.prototype._write = function (msg, encoding, cb) {
-  try {
-    if (Buffer.isBuffer(msg)) {
-      var data = msg.toJSON()
-      data._isBuffer = true
-      this._port.postMessage(data)
-    } else {
-      this._port.postMessage(msg)
-    }
-  } catch (err) {
-    return cb(new Error('PortDuplexStream - disconnected'))
-  }
-  cb()
-}
diff --git a/app/scripts/ui.js b/app/scripts/ui.js
index da100f928..98a036338 100644
--- a/app/scripts/ui.js
+++ b/app/scripts/ui.js
@@ -2,7 +2,7 @@ const injectCss = require('inject-css')
 const OldMetaMaskUiCss = require('../../old-ui/css')
 const NewMetaMaskUiCss = require('../../ui/css')
 const startPopup = require('./popup-core')
-const PortStream = require('./lib/port-stream.js')
+const PortStream = require('extension-port-stream')
 const { getEnvironmentType } = require('./lib/util')
 const { ENVIRONMENT_TYPE_NOTIFICATION } = require('./lib/enums')
 const extension = require('extensionizer')