Merge pull request #277 from JoinColony/negative-balance-logs

Temp: Prevent expenditure balance from going below 0, add logs

src/handlers/actions/moveFunds.ts

@@ -10,6 +10,7 @@ import {
   getUpdatedExpenditureBalances,
   transactionHasEvent,
   getExpenditureByFundingPot,
+  verbose,
 } from '~utils';
 import {
   ColonyActionType,
@@ -85,6 +86,11 @@ export default async (event: ContractEvent): Promise<void> => {
 
   if (targetExpenditure) {
     await updateExpenditureBalances(targetExpenditure, tokenAddress, amount);
+  } else {
+    // @NOTE: Temporary log until issue with negative balances is resolved
+    verbose(
+      `Attempted to find expenditure with funding pot ID: ${toPotId} in colony ${colonyAddress} but it wasn't found. It may be because the transfer was to a domain, or there was a bug.`,
+    );
   }
 };
 
@@ -94,7 +100,7 @@ const updateExpenditureBalances = async (
   amount: string,
 ): Promise<void> => {
   const updatedBalances = getUpdatedExpenditureBalances(
-    expenditure.balances ?? [],
+    expenditure,
     tokenAddress,
     amount,
   );

src/handlers/expenditures/expenditurePayoutClaimed.ts

@@ -78,7 +78,7 @@ export default async (event: ContractEvent): Promise<void> => {
   ).toString();
 
   const updatedBalances = getUpdatedExpenditureBalances(
-    expenditure.balances ?? [],
+    expenditure,
     tokenAddress,
     amountWithFee,
     true,

src/utils/expenditures.ts

@@ -9,6 +9,7 @@ import {
   GetExpenditureByNativeFundingPotIdAndColonyQueryVariables,
 } from '~graphql';
 
+import { output } from './logger';
 import { insertAtIndex } from './arrays';
 
 export const getExpenditureDatabaseId = (
@@ -26,18 +27,42 @@ export const getExpenditureDatabaseId = (
 };
 
 export const getUpdatedExpenditureBalances = (
-  balances: ExpenditureBalance[],
+  expenditure: ExpenditureFragment,
   tokenAddress: string,
   amount: string,
   subtract: boolean = false,
 ): ExpenditureBalance[] => {
+  const balances = expenditure.balances ?? [];
+
   const balanceIndex = balances.findIndex(
     (balance) => balance.tokenAddress === tokenAddress,
   );
   const balance = balanceIndex !== -1 ? balances[balanceIndex] : undefined;
 
   const amountToAdd = BigNumber.from(amount).mul(subtract ? -1 : 1);
-  const updatedAmount = BigNumber.from(balance?.amount ?? 0).add(amountToAdd);
+  let updatedAmount = BigNumber.from(balance?.amount ?? 0).add(amountToAdd);
+
+  if (updatedAmount.lt(0)) {
+    /**
+     * @NOTE: This is a temporary fix to prevent negative balances
+     * The current theory is that when the move funds event is picked up
+     * straight after the expenditure was created, it does not
+     * get returned by DynamoDB yet
+     */
+    output(
+      `Balance of expenditure ${expenditure.id} for token ${tokenAddress} would go negative. This is a bug and needs investigating.`,
+    );
+    updatedAmount = BigNumber.from(0);
+
+    if (process.env.NODE_ENV !== 'development') {
+      fetch('https://hooks.zapier.com/hooks/catch/20362233/2mnk4h2', {
+        method: 'POST',
+        body: JSON.stringify({
+          message: `Balance of expenditure ${expenditure.id} for token ${tokenAddress} would go negative. This is a bug and needs investigating.`,
+        }),
+      });
+    }
+  }
 
   const updatedBalance = {
     ...balance,