feat: add stock screener

src/modules/investments/instruments/stocks/application/stock-screener.service.spec.ts

@@ -0,0 +1,106 @@
+import { NotFoundException, ServiceUnavailableException } from '@nestjs/common';
+
+import type { TbankShare } from '../../../../../integrations/tbank/tbank.api';
+
+import { StockScreenerService } from './stock-screener.service';
+
+const token = 'secret-token';
+const revision = 'revision-1';
+const pageSize = 30;
+
+function share(index: number, overrides: Partial<TbankShare> = {}): TbankShare {
+  return {
+    apiTradeAvailableFlag: true,
+    buyAvailableFlag: true,
+    currency: 'RUB',
+    lot: 1,
+    name: `Share ${index}`,
+    ticker: `T${String(index).padStart(2, '0')}`,
+    uid: `e6123145-9665-43e0-8413-cd61b8aa${String(index).padStart(4, '0')}`,
+    ...overrides,
+  };
+}
+
+describe('StockScreenerService', () => {
+  const access = { current: jest.fn(), local: jest.fn() };
+  const client = { getAllShares: jest.fn() };
+  const logger = { event: jest.fn() };
+  let service: StockScreenerService;
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    access.current.mockResolvedValue({ revision, token });
+    access.local.mockResolvedValue({ revision });
+    client.getAllShares.mockResolvedValue(
+      Array.from({ length: pageSize + 1 }, (_, index) => share(index)),
+    );
+    service = new StockScreenerService(access, client as never, logger as never);
+  });
+
+  it('stores the full selected catalog and returns stable non-overlapping pages', async () => {
+    const first = await service.search('user-1', {});
+    const second = await service.page('user-1', first.searchId, 2);
+
+    expect(first.items).toHaveLength(pageSize);
+    expect(first.hasNext).toBe(true);
+    expect(second).toMatchObject({ asOf: first.asOf, hasNext: false, page: 2, searchId: first.searchId });
+    expect(second.items).toEqual([expect.objectContaining({ ticker: 'T30' })]);
+    expect(client.getAllShares).toHaveBeenCalledTimes(1);
+  });
+
+  it('creates a fresh result for every search and preserves a successful empty result', async () => {
+    client.getAllShares.mockResolvedValueOnce([share(1, { sector: 'energy' })]).mockResolvedValueOnce([share(2, { sector: 'energy' })]);
+
+    const first = await service.search('user-1', { sector: 'finance' });
+    const second = await service.search('user-1', { sector: 'finance' });
+
+    expect(first).toMatchObject({ hasNext: false, items: [], page: 1 });
+    expect(second).toMatchObject({ hasNext: false, items: [], page: 1 });
+    expect(second.searchId).not.toBe(first.searchId);
+    expect(client.getAllShares).toHaveBeenCalledTimes(2);
+  });
+
+  it('does not store a result when the catalog source fails', async () => {
+    client.getAllShares.mockRejectedValueOnce(new ServiceUnavailableException());
+
+    await expect(service.search('user-1', {})).rejects.toBeInstanceOf(ServiceUnavailableException);
+  });
+
+  it('denies missing, foreign, stale, and out-of-range pages without fetching', async () => {
+    const first = await service.search('user-1', {});
+    access.local.mockResolvedValueOnce({ revision: 'revision-2' });
+
+    await expect(service.page('user-1', first.searchId, 1)).rejects.toBeInstanceOf(NotFoundException);
+    await expect(service.page('user-2', first.searchId, 1)).rejects.toBeInstanceOf(NotFoundException);
+    await expect(service.page('user-1', 'missing', 1)).rejects.toBeInstanceOf(NotFoundException);
+    await expect(service.page('user-1', first.searchId, 3)).rejects.toMatchObject({ status: 400 });
+    expect(client.getAllShares).toHaveBeenCalledTimes(1);
+  });
+
+  it('null-normalizes optional source fields and rejects malformed required fields', async () => {
+    client.getAllShares.mockResolvedValueOnce([
+      share(1, {
+        countryOfRisk: undefined,
+        currency: undefined,
+        isin: undefined,
+        realExchange: undefined,
+        sector: undefined,
+        shareType: undefined,
+        ticker: undefined,
+      }),
+    ]);
+    const result = await service.search('user-1', {});
+    expect(result.items[0]).toEqual(expect.objectContaining({ countryOfRisk: null, currency: null, isin: null, logoName: null, ticker: null }));
+
+    client.getAllShares.mockResolvedValueOnce([share(2, { name: ' ' })]);
+    await expect(service.search('user-1', {})).rejects.toBeInstanceOf(ServiceUnavailableException);
+  });
+
+  it('preserves the catalog logo name in screener results', async () => {
+    client.getAllShares.mockResolvedValueOnce([share(1, { brand: { logoName: 'sber.png' } })]);
+
+    const result = await service.search('user-1', {});
+
+    expect(result.items).toEqual([expect.objectContaining({ logoName: 'sber.png' })]);
+  });
+});