Fix rounding issue when sending max tokens (#5695)

* Fix rounding issue when sending max tokens

* Ensure amount row shows exact amount of max tokens on send screen (#2)

* Fix tests

* Change stored redux value from BigNumber to hex string. Fix TokenInput default value

1 files changed, 5 insertions, 4 deletions

diff --git a/ui/app/selectors/confirm-transaction.js b/ui/app/selectors/confirm-transaction.js
index 90924c036..23ef26d95 100644
--- a/ui/app/selectors/confirm-transaction.js
+++ b/ui/app/selectors/confirm-transaction.js
@@ -137,11 +137,12 @@ export const tokenAmountAndToAddressSelector = createSelector(
       const valueParam = params.find(param => param.name === TOKEN_PARAM_VALUE)
       toAddress = toParam ? toParam.value : params[0].value
       const value = valueParam ? Number(valueParam.value) : Number(params[1].value)
-      tokenAmount = roundExponential(value)
 
       if (tokenDecimals) {
-        tokenAmount = calcTokenAmount(value, tokenDecimals)
+        tokenAmount = calcTokenAmount(value, tokenDecimals).toNumber()
       }
+
+      tokenAmount = roundExponential(tokenAmount)
     }
 
     return {
@@ -163,7 +164,7 @@ export const approveTokenAmountAndToAddressSelector = createSelector(
       const value = Number(params.find(param => param.name === TOKEN_PARAM_VALUE).value)
 
       if (tokenDecimals) {
-        tokenAmount = calcTokenAmount(value, tokenDecimals)
+        tokenAmount = calcTokenAmount(value, tokenDecimals).toNumber()
       }
 
       tokenAmount = roundExponential(tokenAmount)
@@ -188,7 +189,7 @@ export const sendTokenTokenAmountAndToAddressSelector = createSelector(
       let value = Number(params.find(param => param.name === TOKEN_PARAM_VALUE).value)
 
       if (tokenDecimals) {
-        value = calcTokenAmount(value, tokenDecimals)
+        value = calcTokenAmount(value, tokenDecimals).toNumber()
       }
 
       tokenAmount = roundExponential(value)