refactor!: support RUB only (WealthLedger/main#55) (#204)

BREAKING CHANGE: per-currency API fields replaced with single RUB Money.

src/modules/investments/brokerage-accounts/brokerage-account.dto.ts

@@ -7,9 +7,6 @@ import { PortfolioStructureDto } from '../portfolio/portfolio.api';
 import { HourlySyncStatusDto } from '../tbank-sync/tbank-sync.dto';
 
 export class UnrealizedReturnDto {
-  @ApiProperty()
-  declare currency: string;
-
   @ApiProperty({ example: '12.345678901' })
   declare absolute: string;
 
@@ -24,17 +21,17 @@ export class UnrealizedReturnDto {
 }
 
 export class PortfolioSummaryDto {
-  @ApiProperty({ type: MoneyDto, isArray: true })
-  declare totalsByCurrency: MoneyDto[];
+  @ApiProperty({ type: MoneyDto })
+  declare totals: MoneyDto;
 
-  @ApiProperty({ type: MoneyDto, isArray: true })
-  declare cashBalances: MoneyDto[];
+  @ApiProperty({ type: MoneyDto })
+  declare cash: MoneyDto;
 
   @ApiProperty({ type: PortfolioStructureDto })
   declare structure: PortfolioStructureDto;
 
-  @ApiProperty({ type: UnrealizedReturnDto, isArray: true })
-  declare unrealizedReturnByCurrency: UnrealizedReturnDto[];
+  @ApiProperty({ type: UnrealizedReturnDto })
+  declare unrealizedReturn: UnrealizedReturnDto;
 
   @ApiProperty({
     type: 'integer',

src/modules/investments/brokerage-accounts/brokerage-accounts.service.spec.ts

@@ -33,7 +33,7 @@ describe('saved brokerage account projection', () => {
   });
 
   it('keeps exact saved totals and independent missing summaries', async () => {
-    const structure = { currencies: [], unvaluedCategories: [] };
+    const structure = { totalValue: '0', hasNegativeValues: false, categories: [], unvaluedCategories: [] };
     portfolio.saved.mockResolvedValue({
       membership: meta,
       accounts: [
@@ -44,11 +44,9 @@ describe('saved brokerage account projection', () => {
           openedOn: null,
           meta,
           snapshot: {
-            cashBalances: [{ currency: 'RUB', value: '10.000000001' }],
+            cash: { currency: 'RUB', value: '10.000000001' },
             structure,
-            totalsByCurrency: [
-              { currency: 'RUB', value: '100000000.000000001' },
-            ],
+            totals: { currency: 'RUB', value: '100000000.000000001' },
             positions: [{ type: 'STOCK', quantity: '1' }, { type: 'BOND', quantity: '2' }],
           },
         },
@@ -64,14 +62,14 @@ describe('saved brokerage account projection', () => {
     });
     const response = await service.list('owner');
     expect(response.data?.[0].portfolioSummary).toEqual({
-      cashBalances: [{ currency: 'RUB', value: '10.000000001' }],
+      cash: { currency: 'RUB', value: '10.000000001' },
       structure,
-      totalsByCurrency: [{ currency: 'RUB', value: '100000000.000000001' }],
+      totals: { currency: 'RUB', value: '100000000.000000001' },
       stockPositionCount: 1,
       bondPositionCount: 1,
       fundPositionCount: 0,
       totalPositionCount: 2,
-      unrealizedReturnByCurrency: [],
+      unrealizedReturn: { absolute: '0', costBasis: '0', percent: null, partial: false },
     });
     expect(response.data?.[1].portfolioSummary).toBeNull();
     expect(response.meta.availability).toBe('available');
@@ -79,74 +77,65 @@ describe('saved brokerage account projection', () => {
   });
 
   it('returns an empty summary from an empty saved portfolio', async () => {
-    const structure = { currencies: [], unvaluedPositions: [], unknownValues: [] };
+    const structure = { totalValue: '0', hasNegativeValues: false, categories: [], unvaluedCategories: [] };
     portfolio.saved.mockResolvedValueOnce({
       membership: meta,
       accounts: [{
         id: 'empty', name: 'Empty', type: 'BROKERAGE', openedOn: null, meta,
-        snapshot: { cashBalances: [], structure, totalsByCurrency: [], positions: [] },
+        snapshot: { cash: { currency: 'RUB', value: '0' }, structure, totals: { currency: 'RUB', value: '0' }, positions: [] },
       }],
     });
 
     expect((await service.list('owner')).data?.[0].portfolioSummary).toEqual({
-      cashBalances: [], structure, totalsByCurrency: [],
+      cash: { currency: 'RUB', value: '0' }, structure, totals: { currency: 'RUB', value: '0' },
       stockPositionCount: 0, bondPositionCount: 0,
       fundPositionCount: 0, totalPositionCount: 0,
-      unrealizedReturnByCurrency: [],
+      unrealizedReturn: { absolute: '0', costBasis: '0', percent: null, partial: false },
     });
   });
 
-  it('calculates exact returns by currency, partial data, and zero cost basis', async () => {
+  it('calculates exact returns, partial data, and zero cost basis', async () => {
     portfolio.saved.mockResolvedValueOnce({
       membership: meta,
       accounts: [{
         id: 'a', name: 'A', type: 'BROKERAGE', openedOn: null, meta,
         snapshot: {
-          cashBalances: [], structure: {}, totalsByCurrency: [
-            { currency: 'RUB', value: '100' }, { currency: 'USD', value: '20' },
-          ],
+          cash: { currency: 'RUB', value: '0' }, structure: {}, totals: { currency: 'RUB', value: '100' },
           positions: [
             { type: 'STOCK', quantity: '2', averagePurchasePrice: { currency: 'RUB', value: '10.000000001' }, absoluteReturn: { currency: 'RUB', value: '0.000000003' } },
             { type: 'BOND', quantity: '0.5', averagePurchasePrice: { currency: 'RUB', value: '20' }, absoluteReturn: { currency: 'RUB', value: '1.25' } },
-            { type: 'FUND', quantity: '3', averagePurchasePrice: { currency: 'USD', value: '2.5' }, absoluteReturn: null },
-            { type: 'STOCK', quantity: '4', averagePurchasePrice: { currency: 'USD', value: '0' }, absoluteReturn: { currency: 'USD', value: '2.5' } },
-            { type: 'CURRENCY', quantity: '100', averagePurchasePrice: { currency: 'EUR', value: '1' }, absoluteReturn: { currency: 'EUR', value: '5' } },
-            { type: 'BOND', quantity: '1', currentValue: { currency: 'CNY', value: '7' }, averagePurchasePrice: null, absoluteReturn: null },
+            { type: 'FUND', quantity: '3', averagePurchasePrice: { currency: 'RUB', value: '2.5' }, absoluteReturn: null },
+            { type: 'BOND', quantity: '1', currentValue: { currency: 'RUB', value: '7' }, averagePurchasePrice: null, absoluteReturn: null },
           ],
         },
       }],
     });
 
     expect((await service.list('owner')).data?.[0].portfolioSummary).toMatchObject({
-      stockPositionCount: 2, bondPositionCount: 2,
-      fundPositionCount: 1, totalPositionCount: 6,
-      unrealizedReturnByCurrency: [
-        { currency: 'CNY', absolute: '0', costBasis: '0', percent: null, partial: true },
-        { currency: 'RUB', absolute: '1.250000003', costBasis: '30.000000002', percent: '4.17', partial: false },
-        { currency: 'USD', absolute: '2.5', costBasis: '0', percent: null, partial: true },
-      ],
+      stockPositionCount: 1, bondPositionCount: 2,
+      fundPositionCount: 1, totalPositionCount: 4,
+      unrealizedReturn: { absolute: '1.250000003', costBasis: '30.000000002', percent: '4.17', partial: true },
     });
   });
 
-  it('omits return percent for a currency with short positions', async () => {
+  it('omits return percent for short positions', async () => {
     portfolio.saved.mockResolvedValueOnce({
       membership: meta,
       accounts: [{
         id: 'a', name: 'A', type: 'BROKERAGE', openedOn: null, meta,
         snapshot: {
-          cashBalances: [], structure: {}, totalsByCurrency: [],
+          cash: { currency: 'RUB', value: '0' }, structure: {}, totals: { currency: 'RUB', value: '0' },
           positions: [
             { type: 'STOCK', quantity: '-2', averagePurchasePrice: { currency: 'RUB', value: '100' }, absoluteReturn: { currency: 'RUB', value: '-20' } },
-            { type: 'STOCK', quantity: '1', averagePurchasePrice: { currency: 'USD', value: '10' }, absoluteReturn: { currency: 'USD', value: '1' } },
+            { type: 'STOCK', quantity: '1', averagePurchasePrice: { currency: 'RUB', value: '10' }, absoluteReturn: { currency: 'RUB', value: '1' } },
           ],
         },
       }],
     });
 
-    expect((await service.list('owner')).data?.[0]?.portfolioSummary?.unrealizedReturnByCurrency).toEqual([
-      { currency: 'RUB', absolute: '-20', costBasis: '-200', percent: null, partial: false },
-      { currency: 'USD', absolute: '1', costBasis: '10', percent: '10', partial: false },
-    ]);
+    expect((await service.list('owner')).data?.[0]?.portfolioSummary?.unrealizedReturn).toEqual(
+      { absolute: '-19', costBasis: '-190', percent: null, partial: false },
+    );
   });
 
   it('observes the latest hourly walk without starting another one', async () => {

src/modules/investments/brokerage-accounts/brokerage-accounts.service.ts

@@ -2,6 +2,7 @@ import { Injectable } from '@nestjs/common';
 import { createHash } from 'node:crypto';
 
 import {
+  add,
   decimalFromString,
   divide,
   formatDecimal,
@@ -10,7 +11,6 @@ import {
 } from '#src/common/decimal';
 
 import { investmentResourceMeta } from '../investment-resource.mapper';
-import { sumMoneyByCurrency } from '../portfolio/domain/portfolio-totals';
 import { PortfolioPositionDto, PortfolioService } from '../portfolio/portfolio.api';
 import { hourlyAttempt, TbankSyncRepository } from '../tbank-sync/tbank-sync.api';
 import {
@@ -22,61 +22,42 @@ import {
 const PERCENT_DECIMAL_PLACES = 2;
 const ZERO_QUANTITY = 0n;
 
-function unrealizedReturns(positions: PortfolioPositionDto[]): UnrealizedReturnDto[] {
-  // Cash-like CURRENCY positions must not duplicate the separately returned cash balances.
-  const investments = positions.filter((position) => position.type !== 'CURRENCY');
-  const absolute = sumMoneyByCurrency(
-    investments.flatMap((position) => position.absoluteReturn ? [position.absoluteReturn] : []),
+function unrealizedReturn(positions: PortfolioPositionDto[]): UnrealizedReturnDto {
+  const absoluteReturn = positions.reduce(
+    (sum, position) => position.absoluteReturn
+      ? add(sum, decimalFromString(position.absoluteReturn.value))
+      : sum,
+    decimalFromString('0'),
   );
-  const costs = sumMoneyByCurrency(
-    investments.flatMap((position) =>
-      position.absoluteReturn && position.averagePurchasePrice
-        ? [{
-            currency: position.absoluteReturn.currency,
-            value: formatDecimal(multiply(
-              decimalFromString(position.averagePurchasePrice.value),
-              decimalFromString(position.quantity),
-            )),
-          }]
-        : [],
-    ),
-  );
-  const partial = new Set(
-    investments.flatMap((position) => {
-      const money = position.absoluteReturn
-        ? null
-        : position.averagePurchasePrice ?? position.currentValue;
-      return money ? [money.currency] : [];
-    }),
+  const costBasis = positions
+    .filter((position) => position.absoluteReturn && position.averagePurchasePrice)
+    .reduce(
+      (sum, position) =>
+        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- Guarded by the filter above.
+        add(sum, multiply(decimalFromString(position.averagePurchasePrice!.value), decimalFromString(position.quantity))),
+      decimalFromString('0'),
+    );
+  const partial = positions.some(
+    (position) => !position.absoluteReturn && (position.averagePurchasePrice || position.currentValue),
   );
   // A short position has negative cost basis, so a percent would flip sign or net out.
-  const withShorts = new Set(
-    investments.flatMap((position) => {
-      const money = position.absoluteReturn ?? position.averagePurchasePrice ?? position.currentValue;
-      return money && decimalFromString(position.quantity).value < ZERO_QUANTITY ? [money.currency] : [];
-    }),
+  const withShorts = positions.some(
+    (position) =>
+      (position.absoluteReturn ?? position.averagePurchasePrice ?? position.currentValue) &&
+      decimalFromString(position.quantity).value < ZERO_QUANTITY,
   );
-  const currencies = new Set([...absolute, ...costs].map((money) => money.currency));
-  return [...new Set([...currencies, ...partial])]
-    .sort((left, right) => left.localeCompare(right))
-    .map((currency) => {
-      const absoluteReturn = absolute.find((money) => money.currency === currency)?.value ?? '0';
-      const costBasis = costs.find((money) => money.currency === currency)?.value ?? '0';
-      const cost = decimalFromString(costBasis);
-      return {
-        currency,
-        absolute: absoluteReturn,
-        costBasis,
-        percent: isZero(cost) || withShorts.has(currency)
-          ? null
-          : formatDecimal(divide(
-              multiply(decimalFromString(absoluteReturn), decimalFromString('100')),
-              cost,
-              PERCENT_DECIMAL_PLACES,
-            )),
-        partial: partial.has(currency),
-      };
-    });
+  return {
+    absolute: formatDecimal(absoluteReturn),
+    costBasis: formatDecimal(costBasis),
+    percent: isZero(costBasis) || withShorts
+      ? null
+      : formatDecimal(divide(
+          multiply(absoluteReturn, decimalFromString('100')),
+          costBasis,
+          PERCENT_DECIMAL_PLACES,
+        )),
+    partial,
+  };
 }
 
 @Injectable()
@@ -98,10 +79,10 @@ export class BrokerageAccountsService {
             openedOn: account.openedOn,
             portfolioSummary: account.snapshot
               ? {
-                  totalsByCurrency: account.snapshot.totalsByCurrency,
-                  cashBalances: account.snapshot.cashBalances,
+                  totals: account.snapshot.totals,
+                  cash: account.snapshot.cash,
                   structure: account.snapshot.structure,
-                  unrealizedReturnByCurrency: unrealizedReturns(account.snapshot.positions),
+                  unrealizedReturn: unrealizedReturn(account.snapshot.positions),
                   stockPositionCount: account.snapshot.positions.filter(
                     (position) => position.type === 'STOCK',
                   ).length,