backend/test/openapi-contract.e2e-spec.ts

import { INestApplication } from '@nestjs/common';
import { Test } from '@nestjs/testing';
import { execFileSync } from 'node:child_process';
import { mkdtemp, readFile, rm, writeFile } from 'node:fs/promises';
import { tmpdir } from 'node:os';
import { resolve } from 'node:path';
import { AppModule } from '../src/app.module';
import { configureApp } from '../src/main';
import { createOpenApiDocument } from '../src/openapi';

describe('OpenAPI contract (integration)', () => {
  let app: INestApplication;

  beforeAll(async () => {
    const module = await Test.createTestingModule({
      imports: [AppModule],
    }).compile();
    app = module.createNestApplication();
    configureApp(app);
    await app.init();
  });

  afterAll(() => app.close());

  it('generates the runtime contract without server startup or deployment configuration', async () => {
    const directory = await mkdtemp(resolve(tmpdir(), 'wealthledger-openapi-'));
    try {
      const networkGuard = resolve(directory, 'no-network.cjs');
      await writeFile(
        networkGuard,
        `
        const net = require('node:net');
        const forbidden = () => { throw new Error('Schema generation must not use the network'); };
        net.Server.prototype.listen = forbidden;
        net.Socket.prototype.connect = forbidden;
      `,
      );
      execFileSync(
        process.execPath,
        [
          '--require',
          networkGuard,
          resolve(__dirname, '../scripts/generate-openapi.cjs'),
        ],
        {
          cwd: directory,
          env: { PATH: process.env.PATH },
          timeout: 30_000,
        },
      );
      const generated = JSON.parse(
        await readFile(resolve(directory, 'openapi.json'), 'utf8'),
      ) as unknown;
      expect(generated).toEqual(createOpenApiDocument(app));
    } finally {
      await rm(directory, { recursive: true, force: true });
    }
  });
});