Merge pull request #4606 from MetaMask/WatchTokenFeature

Add metamask_watchAsset

3 files changed, 133 insertions, 6 deletions

diff --git a/app/scripts/background.js b/app/scripts/background.js
index d4d87e0d5..546fef569 100644
--- a/app/scripts/background.js
+++ b/app/scripts/background.js
@@ -256,6 +256,7 @@ function setupController (initState, initLangCode) {
     showUnconfirmedMessage: triggerUi,
     unlockAccountMessage: triggerUi,
     showUnapprovedTx: triggerUi,
+    showWatchAssetUi: showWatchAssetUi,
     // initial state
     initState,
     // initial locale code
@@ -443,9 +444,28 @@ function triggerUi () {
   })
 }
 
+/**
+ * Opens the browser popup for user confirmation of watchAsset
+ * then it waits until user interact with the UI
+ */
+function showWatchAssetUi () {
+  triggerUi()
+  return new Promise(
+    (resolve) => {
+      var interval = setInterval(() => {
+        if (!notificationIsOpen) {
+          clearInterval(interval)
+          resolve()
+        }
+      }, 1000)
+    }
+  )
+}
+
 // On first install, open a window to MetaMask website to how-it-works.
 extension.runtime.onInstalled.addListener(function (details) {
   if ((details.reason === 'install') && (!METAMASK_DEBUG)) {
     extension.tabs.create({url: 'https://metamask.io/#how-it-works'})
   }
 })
+
diff --git a/app/scripts/controllers/preferences.js b/app/scripts/controllers/preferences.js
index 1b85e4fd1..464a37017 100644
--- a/app/scripts/controllers/preferences.js
+++ b/app/scripts/controllers/preferences.js
@@ -1,5 +1,6 @@
 const ObservableStore = require('obs-store')
 const normalizeAddress = require('eth-sig-util').normalize
+const { isValidAddress } = require('ethereumjs-util')
 const extend = require('xtend')
 
 
@@ -14,6 +15,7 @@ class PreferencesController {
    * @property {string} store.currentAccountTab Indicates the selected tab in the ui
    * @property {array} store.tokens The tokens the user wants display in their token lists
    * @property {object} store.accountTokens The tokens stored per account and then per network type
+   * @property {object} store.assetImages Contains assets objects related to assets added
    * @property {boolean} store.useBlockie The users preference for blockie identicons within the UI
    * @property {object} store.featureFlags A key-boolean map, where keys refer to features and booleans to whether the
    * user wishes to see that feature
@@ -26,7 +28,9 @@ class PreferencesController {
       frequentRpcList: [],
       currentAccountTab: 'history',
       accountTokens: {},
+      assetImages: {},
       tokens: [],
+      suggestedTokens: {},
       useBlockie: false,
       featureFlags: {},
       currentLocale: opts.initLangCode,
@@ -37,6 +41,7 @@ class PreferencesController {
     this.diagnostics = opts.diagnostics
     this.network = opts.network
     this.store = new ObservableStore(initState)
+    this.showWatchAssetUi = opts.showWatchAssetUi
     this._subscribeProviderType()
   }
 // PUBLIC METHODS
@@ -51,6 +56,53 @@ class PreferencesController {
     this.store.updateState({ useBlockie: val })
   }
 
+  getSuggestedTokens () {
+    return this.store.getState().suggestedTokens
+  }
+
+  getAssetImages () {
+    return this.store.getState().assetImages
+  }
+
+  addSuggestedERC20Asset (tokenOpts) {
+    this._validateERC20AssetParams(tokenOpts)
+    const suggested = this.getSuggestedTokens()
+    const { rawAddress, symbol, decimals, image } = tokenOpts
+    const address = normalizeAddress(rawAddress)
+    const newEntry = { address, symbol, decimals, image }
+    suggested[address] = newEntry
+    this.store.updateState({ suggestedTokens: suggested })
+  }
+
+  /**
+   * RPC engine middleware for requesting new asset added
+   *
+   * @param req
+   * @param res
+   * @param {Function} - next
+   * @param {Function} - end
+   */
+  async requestWatchAsset (req, res, next, end) {
+    if (req.method === 'metamask_watchAsset') {
+      const { type, options } = req.params
+      switch (type) {
+        case 'ERC20':
+          const result = await this._handleWatchAssetERC20(options)
+          if (result instanceof Error) {
+            end(result)
+          } else {
+            res.result = result
+            end()
+          }
+          break
+        default:
+          end(new Error(`Asset of type ${type} not supported`))
+      }
+    } else {
+      next()
+    }
+  }
+
   /**
    * Getter for the `useBlockie` property
    *
@@ -186,6 +238,13 @@ class PreferencesController {
     return selected
   }
 
+  removeSuggestedTokens () {
+    return new Promise((resolve, reject) => {
+      this.store.updateState({ suggestedTokens: {} })
+      resolve({})
+    })
+  }
+
   /**
    * Setter for the `selectedAddress` property
    *
@@ -232,11 +291,11 @@ class PreferencesController {
    * @returns {Promise<array>} Promises the new array of AddedToken objects.
    *
    */
-  async addToken (rawAddress, symbol, decimals) {
+  async addToken (rawAddress, symbol, decimals, image) {
     const address = normalizeAddress(rawAddress)
     const newEntry = { address, symbol, decimals }
-
     const tokens = this.store.getState().tokens
+    const assetImages = this.getAssetImages()
     const previousEntry = tokens.find((token, index) => {
       return token.address === address
     })
@@ -247,7 +306,8 @@ class PreferencesController {
     } else {
       tokens.push(newEntry)
     }
-    this._updateAccountTokens(tokens)
+    assetImages[address] = image
+    this._updateAccountTokens(tokens, assetImages)
     return Promise.resolve(tokens)
   }
 
@@ -260,8 +320,10 @@ class PreferencesController {
    */
   removeToken (rawAddress) {
     const tokens = this.store.getState().tokens
+    const assetImages = this.getAssetImages()
     const updatedTokens = tokens.filter(token => token.address !== rawAddress)
-    this._updateAccountTokens(updatedTokens)
+    delete assetImages[rawAddress]
+    this._updateAccountTokens(updatedTokens, assetImages)
     return Promise.resolve(updatedTokens)
   }
 
@@ -387,6 +449,7 @@ class PreferencesController {
   //
   // PRIVATE METHODS
   //
+
   /**
    * Subscription to network provider type.
    *
@@ -405,10 +468,10 @@ class PreferencesController {
    * @param {array} tokens Array of tokens to be updated.
    *
    */
-  _updateAccountTokens (tokens) {
+  _updateAccountTokens (tokens, assetImages) {
     const { accountTokens, providerType, selectedAddress } = this._getTokenRelatedStates()
     accountTokens[selectedAddress][providerType] = tokens
-    this.store.updateState({ accountTokens, tokens })
+    this.store.updateState({ accountTokens, tokens, assetImages })
   }
 
   /**
@@ -438,6 +501,47 @@ class PreferencesController {
     const tokens = accountTokens[selectedAddress][providerType]
     return { tokens, accountTokens, providerType, selectedAddress }
   }
+
+  /**
+   * Handle the suggestion of an ERC20 asset through `watchAsset`
+   * *
+   * @param {Promise} promise Promise according to addition of ERC20 token
+   *
+   */
+  async _handleWatchAssetERC20 (options) {
+    const { address, symbol, decimals, image } = options
+    const rawAddress = address
+    try {
+      this._validateERC20AssetParams({ rawAddress, symbol, decimals })
+    } catch (err) {
+      return err
+    }
+    const tokenOpts = { rawAddress, decimals, symbol, image }
+    this.addSuggestedERC20Asset(tokenOpts)
+    return this.showWatchAssetUi().then(() => {
+      const tokenAddresses = this.getTokens().filter(token => token.address === normalizeAddress(rawAddress))
+      return tokenAddresses.length > 0
+    })
+  }
+
+  /**
+   * Validates that the passed options for suggested token have all required properties.
+   *
+   * @param {Object} opts The options object to validate
+   * @throws {string} Throw a custom error indicating that address, symbol and/or decimals
+   * doesn't fulfill requirements
+   *
+   */
+  _validateERC20AssetParams (opts) {
+    const { rawAddress, symbol, decimals } = opts
+    if (!rawAddress || !symbol || !decimals) throw new Error(`Cannot suggest token without address, symbol, and decimals`)
+    if (!(symbol.length < 6)) throw new Error(`Invalid symbol ${symbol} more than five characters`)
+    const numDecimals = parseInt(decimals, 10)
+    if (isNaN(numDecimals) || numDecimals > 36 || numDecimals < 0) {
+      throw new Error(`Invalid decimals ${decimals} must be at least 0, and not over 36`)
+    }
+    if (!isValidAddress(rawAddress)) throw new Error(`Invalid address ${rawAddress}`)
+  }
 }
 
 module.exports = PreferencesController
diff --git a/app/scripts/metamask-controller.js b/app/scripts/metamask-controller.js
index a6215d51b..98cb62bfa 100644
--- a/app/scripts/metamask-controller.js
+++ b/app/scripts/metamask-controller.js
@@ -92,6 +92,7 @@ module.exports = class MetamaskController extends EventEmitter {
     this.preferencesController = new PreferencesController({
       initState: initState.PreferencesController,
       initLangCode: opts.initLangCode,
+      showWatchAssetUi: opts.showWatchAssetUi,
       network: this.networkController,
     })
 
@@ -386,6 +387,7 @@ module.exports = class MetamaskController extends EventEmitter {
       setSelectedAddress: nodeify(preferencesController.setSelectedAddress, preferencesController),
       addToken: nodeify(preferencesController.addToken, preferencesController),
       removeToken: nodeify(preferencesController.removeToken, preferencesController),
+      removeSuggestedTokens: nodeify(preferencesController.removeSuggestedTokens, preferencesController),
       setCurrentAccountTab: nodeify(preferencesController.setCurrentAccountTab, preferencesController),
       setAccountLabel: nodeify(preferencesController.setAccountLabel, preferencesController),
       setFeatureFlag: nodeify(preferencesController.setFeatureFlag, preferencesController),
@@ -1250,6 +1252,7 @@ module.exports = class MetamaskController extends EventEmitter {
     engine.push(createOriginMiddleware({ origin }))
     engine.push(createLoggerMiddleware({ origin }))
     engine.push(filterMiddleware)
+    engine.push(this.preferencesController.requestWatchAsset.bind(this.preferencesController))
     engine.push(createProviderMiddleware({ provider: this.provider }))
 
     // setup connection