Derive available tx metadata (#1257)

* Derive "from" and "unit" parameters from current transaction when possible

* Fix tsc errors

* Address changes

common/components/ConfirmationModal/components/Body/components/Addresses.tsx

@@ -8,6 +8,7 @@ import { connect } from 'react-redux';
 import { SerializedTransaction } from 'components/renderCbs';
 import { AppState } from 'reducers';
 import { getFrom, getUnit, isEtherTransaction } from 'selectors/transaction';
+import { toChecksumAddress } from 'ethereumjs-util';
 
 interface StateProps {
   from: AppState['transaction']['meta']['from'];
@@ -24,7 +25,9 @@ class AddressesClass extends Component<StateProps> {
     return (
       <SerializedTransaction
         withSerializedTransaction={(_, { to, data }) => {
-          const toFormatted = isToken ? ERC20.transfer.decodeInput(data)._to : to;
+          const toFormatted = toChecksumAddress(
+            isToken ? ERC20.transfer.decodeInput(data)._to : to
+          );
           return (
             <div className="tx-modal-address">
               <div className="tx-modal-address-from">

common/selectors/transaction/meta.ts

@@ -3,13 +3,60 @@ import { getTransactionState } from './transaction';
 import { getToken } from 'selectors/wallet';
 import { isNetworkUnit } from 'selectors/config/wallet';
 import { getDecimalFromEtherUnit } from 'libs/units';
+import { getSerializedTransaction } from 'selectors/transaction';
+import EthTx from 'ethereumjs-tx';
+import { getCustomTokens } from 'selectors/customTokens';
+import { getNetworkConfig } from 'selectors/config';
+import { Token } from '../../../shared/types/network';
+import { stripHexPrefixAndLower } from 'libs/values';
+import { toChecksumAddress } from 'ethereumjs-util';
 
 const getMetaState = (state: AppState) => getTransactionState(state).meta;
-const getFrom = (state: AppState) => getMetaState(state).from;
+const getFrom = (state: AppState) => {
+  const serializedTransaction = getSerializedTransaction(state);
+  // attempt to get the from address from the transaction
+  if (serializedTransaction) {
+    const transactionInstance = new EthTx(serializedTransaction);
+    try {
+      const from = transactionInstance.from;
+      if (from) {
+        return toChecksumAddress(from.toString('hex'));
+      }
+    } catch (e) {
+      console.warn(e);
+    }
+  }
+  return getMetaState(state).from;
+};
 const getDecimal = (state: AppState) => getMetaState(state).decimal;
+
 const getTokenTo = (state: AppState) => getMetaState(state).tokenTo;
 const getTokenValue = (state: AppState) => getMetaState(state).tokenValue;
-const getUnit = (state: AppState) => getMetaState(state).unit;
+const getUnit = (state: AppState) => {
+  const serializedTransaction = getSerializedTransaction(state);
+  // attempt to get the to address from the transaction
+  if (serializedTransaction) {
+    const transactionInstance = new EthTx(serializedTransaction);
+    const { to } = transactionInstance;
+    if (to) {
+      // see if any tokens match
+      let networkTokens: null | Token[] = null;
+      const customTokens = getCustomTokens(state);
+      const networkConfig = getNetworkConfig(state);
+      if (!networkConfig.isCustom) {
+        networkTokens = networkConfig.tokens;
+      }
+      const mergedTokens = networkTokens ? [...networkTokens, ...customTokens] : customTokens;
+      const stringTo = toChecksumAddress(stripHexPrefixAndLower(to.toString('hex')));
+      const result = mergedTokens.find(t => t.address === stringTo);
+      if (result) {
+        return result.symbol;
+      }
+    }
+  }
+
+  return getMetaState(state).unit;
+};
 const getPreviousUnit = (state: AppState) => getMetaState(state).previousUnit;
 const getDecimalFromUnit = (state: AppState, unit: string) => {
   if (isNetworkUnit(state, unit)) {