refactor: organize backend by business responsibility

src/common/dto-validation.spec.ts

@@ -1,9 +1,9 @@
 import { BadRequestException, ValidationPipe } from '@nestjs/common';
-import { CredentialsDto } from '../auth/auth.dto';
+import { CredentialsDto } from '../modules/auth/presentation/auth.dto';
 import {
   CreateBankCardDto,
   UpdateBankCardDto,
-} from '../bank-cards/bank-card.dto';
+} from '../modules/banking/bank-cards/presentation/bank-card.dto';
 
 describe('DTO validation', () => {
   const pipe = new ValidationPipe({ transform: true, whitelist: true });

src/common/money.dto.ts

@@ -1,6 +1,7 @@
 import { ApiProperty } from '@nestjs/swagger';
+import type { Money } from './money.types';
 
-export class MoneyDto {
+export class MoneyDto implements Money {
   @ApiProperty()
   declare currency: string;
 

src/common/money.types.ts

@@ -0,0 +1 @@
+export type Money = { currency: string; value: string };

src/common/rub-money.spec.ts

@@ -1,57 +0,0 @@
-import { parseRubMoney, rubMoney } from './rub-money';
-
-describe('RUB money', () => {
-  it.each([
-    ['0', 0n],
-    ['-100', -10000n],
-    ['0.01', 1n],
-    ['123.4', 12340n],
-    ['90071992547409.93', 9007199254740993n],
-    ['92233720368547758.07', 2n ** 63n - 1n],
-    ['-92233720368547758.08', -(2n ** 63n)],
-  ])('roundtrips %s exactly', (value, kopecks) => {
-    expect(parseRubMoney({ currency: 'RUB', value })).toBe(kopecks);
-    expect(rubMoney(kopecks)).toEqual({ currency: 'RUB', value });
-  });
-
-  it.each([
-    '92233720368547758.08',
-    '-92233720368547758.09',
-    '1.001',
-    '1.000',
-    'NaN',
-    'Infinity',
-    '1e2',
-    '1,23',
-    '',
-    ' 1',
-    '1\n',
-    '01',
-  ])('rejects invalid input %s without rounding', (value) => {
-    expect(() => parseRubMoney({ currency: 'RUB', value })).toThrow();
-  });
-
-  it('rejects other currencies and non-string values', () => {
-    expect(() => parseRubMoney({ currency: 'USD', value: '1' })).toThrow();
-    expect(() =>
-      parseRubMoney({ currency: 'RUB', value: 1 as unknown as string }),
-    ).toThrow();
-  });
-
-  it('requires positive operation amounts, including at the maximum', () => {
-    for (const value of ['0', '-0.00', '-0.01'])
-      expect(() => parseRubMoney({ currency: 'RUB', value }, true)).toThrow();
-    expect(parseRubMoney({ currency: 'RUB', value: '0.01' }, true)).toBe(1n);
-    expect(
-      parseRubMoney({ currency: 'RUB', value: '92233720368547758.07' }, true),
-    ).toBe(2n ** 63n - 1n);
-  });
-
-  it('formats computed sums beyond the storage range without losing precision', () => {
-    expect(rubMoney(2n * (2n ** 63n - 1n))).toEqual({
-      currency: 'RUB',
-      value: '184467440737095516.14',
-    });
-    expect(rubMoney(-1n)).toEqual({ currency: 'RUB', value: '-0.01' });
-  });
-});

src/common/rub-money.ts

@@ -1,27 +0,0 @@
-import { decimalFromString, formatDecimal } from './decimal';
-import { MoneyDto } from './money.dto';
-
-export function parseRubMoney(money: MoneyDto, positive = false): bigint {
-  if (
-    money?.currency !== 'RUB' ||
-    typeof money.value !== 'string' ||
-    money.value !== money.value.trim()
-  )
-    throw new TypeError('Expected RUB money with a decimal string');
-  const amount = decimalFromString(money.value);
-  if (amount.scale > 2)
-    throw new RangeError('RUB money supports at most two decimal places');
-  const kopecks = amount.value * 10n ** BigInt(2 - amount.scale);
-  if (kopecks < -(2n ** 63n) || kopecks > 2n ** 63n - 1n)
-    throw new RangeError('RUB money is outside the signed 64-bit range');
-  if (positive && kopecks <= 0n)
-    throw new RangeError('Operation amount must be positive');
-  return kopecks;
-}
-
-export function rubMoney(kopecks: bigint): MoneyDto {
-  return {
-    currency: 'RUB',
-    value: formatDecimal({ value: kopecks, scale: 2 }),
-  };
-}