refactor: replace ignored numeric literals with constants

src/modules/banking/bank-cards/domain/bank-card.calculations.ts

@@ -1,4 +1,6 @@
+import { ISO_DATE_LENGTH, ISO_DATE_START } from '../../../../common/time';
 import { BankOperationKind } from './bank-operation-kind';
+import { ZERO_KOPECKS } from './rub-money';
 
 export function moscowToday(now = new Date()): string {
   return new Intl.DateTimeFormat('en-CA', {
@@ -10,11 +12,11 @@ export function moscowToday(now = new Date()): string {
 }
 
 export function isCalendarDate(value: string): boolean {
-  if (value.length !== 10 || !/^\d{4}-\d{2}-\d{2}$/.test(value)) return false;
+  if (value.length !== ISO_DATE_LENGTH || !/^\d{4}-\d{2}-\d{2}$/.test(value)) return false;
   if (value.startsWith('0000')) return false;
   const date = new Date(`${value}T00:00:00.000Z`);
   return (
-    !Number.isNaN(date.getTime()) && date.toISOString().slice(0, 10) === value
+    !Number.isNaN(date.getTime()) && date.toISOString().slice(ISO_DATE_START, ISO_DATE_LENGTH) === value
   );
 }
 
@@ -63,8 +65,8 @@ export function bankSummary(
     kind: string;
   }>,
 ) {
-  let expenses = 0n;
-  let refunds = 0n;
+  let expenses = ZERO_KOPECKS;
+  let refunds = ZERO_KOPECKS;
   const categories = new Map<
     string,
     { categoryId: string; expenses: bigint; net: bigint; refunds: bigint }
@@ -81,19 +83,19 @@ export function bankSummary(
     const expense =
       operation.kind === BankOperationKind.Expense ?
         operation.amountKopecks :
-        0n;
+        ZERO_KOPECKS;
     const refund =
       operation.kind === BankOperationKind.Refund ?
         operation.amountKopecks :
-        0n;
+        ZERO_KOPECKS;
     expenses += expense;
     refunds += refund;
     if (operation.categoryId !== null) {
       const category = categories.get(operation.categoryId) ?? {
         categoryId: operation.categoryId,
-        expenses: 0n,
-        refunds: 0n,
-        net: 0n,
+        expenses: ZERO_KOPECKS,
+        refunds: ZERO_KOPECKS,
+        net: ZERO_KOPECKS,
       };
       category.expenses += expense;
       category.refunds += refund;