From a59972dcabc56c3d92f09ba1b88a2ded70ce8c34 Mon Sep 17 00:00:00 2001
From: Alexander Tseung <alextsg@users.noreply.github.com>
Date: Fri, 13 Oct 2017 17:14:48 -0400
Subject: [PATCH] Prevent adding already added tokens (#2362)

---
 ui/app/add-token.js                        | 28 +++++++++++++++++++---
 ui/app/css/itcss/components/add-token.scss | 15 +++++++++++-
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/ui/app/add-token.js b/ui/app/add-token.js
index f723ff07c..90edc8de1 100644
--- a/ui/app/add-token.js
+++ b/ui/app/add-token.js
@@ -22,14 +22,17 @@ const ethUtil = require('ethereumjs-util')
 const abi = require('human-standard-token-abi')
 const Eth = require('ethjs-query')
 const EthContract = require('ethjs-contract')
+const R = require('ramda')
 
 const emptyAddr = '0x0000000000000000000000000000000000000000'
 
 module.exports = connect(mapStateToProps, mapDispatchToProps)(AddTokenScreen)
 
 function mapStateToProps (state) {
+  const { identities, tokens } = state.metamask
   return {
-    identities: state.metamask.identities,
+    identities,
+    tokens,
   }
 }
 
@@ -101,6 +104,15 @@ AddTokenScreen.prototype.tokenAddressDidChange = function (e) {
   }
 }
 
+AddTokenScreen.prototype.checkExistingAddresses = function (address) {
+  const tokensList = this.props.tokens
+  const matchesAddress = existingToken => {
+    return existingToken.address.toLowerCase() === address.toLowerCase()
+  }
+
+  return R.any(matchesAddress)(tokensList)
+}
+
 AddTokenScreen.prototype.validate = function () {
   const errors = {}
   const identitiesList = Object.keys(this.props.identities)
@@ -128,6 +140,11 @@ AddTokenScreen.prototype.validate = function () {
     if (ownAddress) {
       errors.customAddress = 'Personal address detected. Input the token contract address.'
     }
+
+    const tokenAlreadyAdded = this.checkExistingAddresses(customAddress)
+    if (tokenAlreadyAdded) {
+      errors.customAddress = 'Token has already been added.'
+    }
   } else if (
     Object.entries(selectedTokens)
       .reduce((isEmpty, [ symbol, isSelected ]) => (
@@ -217,12 +234,14 @@ AddTokenScreen.prototype.renderTokenList = function () {
   return Array(6).fill(undefined)
     .map((_, i) => {
       const { logo, symbol, name, address } = results[i] || {}
+      const tokenAlreadyAdded = this.checkExistingAddresses(address)
       return Boolean(logo || symbol || name) && (
         h('div.add-token__token-wrapper', {
-          className: classnames('add-token__token-wrapper', {
+          className: classnames({
             'add-token__token-wrapper--selected': selectedTokens[address],
+            'add-token__token-wrapper--disabled': tokenAlreadyAdded,
           }),
-          onClick: () => this.toggleToken(address, results[i]),
+          onClick: () => !tokenAlreadyAdded && this.toggleToken(address, results[i]),
         }, [
           h('div.add-token__token-icon', {
             style: {
@@ -233,6 +252,9 @@ AddTokenScreen.prototype.renderTokenList = function () {
             h('div.add-token__token-symbol', symbol),
             h('div.add-token__token-name', name),
           ]),
+          tokenAlreadyAdded && (
+            h('div.add-token__token-message', 'Already added')
+          ),
         ])
       )
     })
diff --git a/ui/app/css/itcss/components/add-token.scss b/ui/app/css/itcss/components/add-token.scss
index d5d1aab71..aa8221c9a 100644
--- a/ui/app/css/itcss/components/add-token.scss
+++ b/ui/app/css/itcss/components/add-token.scss
@@ -4,7 +4,6 @@
   flex-flow: column nowrap;
   align-items: center;
   position: relative;
-  top: -36px;
   z-index: 12;
   font-family: 'DIN Next Light';
 
@@ -189,6 +188,7 @@
     border-radius: 10px;
     cursor: pointer;
     border: 2px solid transparent;
+    position: relative;
 
     &:hover {
       border: 2px solid rgba($malibu-blue, .5);
@@ -197,6 +197,11 @@
     &--selected {
       border: 2px solid $malibu-blue !important;
     }
+
+    &--disabled {
+      opacity: .4;
+      pointer-events: none;
+    }
   }
 
   &__token-name {
@@ -223,6 +228,14 @@
     flex: 0 0 auto;
   }
 
+  &__token-message {
+    position: absolute;
+    color: $caribbean-green;
+    font-size: 11px;
+    bottom: 0;
+    left: 85px;
+  }
+
   &__confirmation-token-list {
     display: flex;
     flex-flow: column nowrap;