Merge pull request #4895 from MetaMask/fix-confirm

Add rounding to large exponential numbers. Fix overflows

1 files changed, 9 insertions, 0 deletions

diff --git a/ui/app/helpers/confirm-transaction/util.js b/ui/app/helpers/confirm-transaction/util.js
index f015b2bf5..a37778c19 100644
--- a/ui/app/helpers/confirm-transaction/util.js
+++ b/ui/app/helpers/confirm-transaction/util.js
@@ -3,6 +3,7 @@ import currencies from 'currency-formatter/currencies'
 import abi from 'human-standard-token-abi'
 import abiDecoder from 'abi-decoder'
 import ethUtil from 'ethereumjs-util'
+import BigNumber from 'bignumber.js'
 
 abiDecoder.addABI(abi)
 
@@ -137,3 +138,11 @@ export function convertTokenToFiat ({
 export function hasUnconfirmedTransactions (state) {
   return unconfirmedTransactionsCountSelector(state) > 0
 }
+
+export function roundExponential (value) {
+  const PRECISION = 4
+  const bigNumberValue = new BigNumber(value)
+
+  // In JS, numbers with exponentials greater than 20 get displayed as an exponential.
+  return bigNumberValue.e > 20 ? Number(bigNumberValue.toPrecision(PRECISION)) : value
+}