CommunitySolidServer/test/unit/logging/LazyLoggerFactory.test.ts

import { LazyLoggerFactory } from '../../../src/logging/LazyLoggerFactory';
import type { Logger } from '../../../src/logging/Logger';
import type { LoggerFactory } from '../../../src/logging/LoggerFactory';

describe('LazyLoggerFactory', (): void => {
  let lazyLoggerFactory: LazyLoggerFactory;
  let dummyLoggerFactory: jest.Mocked<LoggerFactory>;

  beforeEach(async(): Promise<void> => {
    lazyLoggerFactory = new LazyLoggerFactory();
    dummyLoggerFactory = {
      createLogger: jest.fn((): jest.Mocked<Logger> => ({
        log: jest.fn((): any => null),
      }) as any),
    } as any;
  });

  it('does not allow reading the internal factory before it is set.', (): void => {
    expect((): void => {
      expect(lazyLoggerFactory.loggerFactory).toBeNull();
    }).toThrow('Logger factory not yet set.');
  });

  it('allows setting the internal factory.', (): void => {
    lazyLoggerFactory.loggerFactory = dummyLoggerFactory;
    expect(lazyLoggerFactory.loggerFactory).toBe(dummyLoggerFactory);
  });

  it('creates loggers with the right labels.', (): void => {
    lazyLoggerFactory.createLogger('LoggerA');
    lazyLoggerFactory.createLogger('LoggerB');

    lazyLoggerFactory.loggerFactory = dummyLoggerFactory;

    expect(dummyLoggerFactory.createLogger).toHaveBeenCalledTimes(2);
    expect(dummyLoggerFactory.createLogger).toHaveBeenNthCalledWith(1, 'LoggerA');
    expect(dummyLoggerFactory.createLogger).toHaveBeenNthCalledWith(2, 'LoggerB');

    lazyLoggerFactory.createLogger('LoggerC');
    expect(dummyLoggerFactory.createLogger).toHaveBeenCalledTimes(3);
    expect(dummyLoggerFactory.createLogger).toHaveBeenNthCalledWith(3, 'LoggerC');
  });

  it('emits logged messages after a logger is set.', (): void => {
    const loggerA = lazyLoggerFactory.createLogger('LoggerA');
    const loggerB = lazyLoggerFactory.createLogger('LoggerB');
    loggerA.warn('message1');
    loggerB.warn('message2');
    loggerB.error('message3');
    loggerA.error('message4');

    lazyLoggerFactory.loggerFactory = dummyLoggerFactory;

    const wrappedA = dummyLoggerFactory.createLogger.mock.results[0].value as jest.Mocked<Logger>;
    expect(wrappedA.log).toHaveBeenCalledTimes(2);
    expect(wrappedA.log).toHaveBeenNthCalledWith(1, 'warn', 'message1');
    expect(wrappedA.log).toHaveBeenNthCalledWith(2, 'error', 'message4');

    const wrappedB = dummyLoggerFactory.createLogger.mock.results[1].value as jest.Mocked<Logger>;
    expect(wrappedB.log).toHaveBeenCalledTimes(2);
    expect(wrappedB.log).toHaveBeenNthCalledWith(1, 'warn', 'message2');
    expect(wrappedB.log).toHaveBeenNthCalledWith(2, 'error', 'message3');
  });

  it('does not store more messages than the buffer limit.', (): void => {
    lazyLoggerFactory = new LazyLoggerFactory({ bufferSize: 100 });
    const loggerA = lazyLoggerFactory.createLogger('LoggerA');
    const loggerB = lazyLoggerFactory.createLogger('LoggerB');

    for (let i = 0; i < 50; i++) {
      loggerA.info('info');
    }
    for (let i = 0; i < 50; i++) {
      loggerB.info('info');
    }

    lazyLoggerFactory.loggerFactory = dummyLoggerFactory;

    expect(dummyLoggerFactory.createLogger).toHaveBeenCalledTimes(3);
    const wrappedA = dummyLoggerFactory.createLogger.mock.results[0].value as jest.Mocked<Logger>;
    const wrappedB = dummyLoggerFactory.createLogger.mock.results[1].value as jest.Mocked<Logger>;
    const warningLogger = dummyLoggerFactory.createLogger.mock.results[2].value as jest.Mocked<Logger>;

    expect(wrappedA.log).toHaveBeenCalledTimes(50);
    expect(wrappedB.log).toHaveBeenCalledTimes(49);
    expect(warningLogger.log).toHaveBeenCalledTimes(1);
    expect(warningLogger.log).toHaveBeenCalledWith('warn', 'Memory-buffered logging limit of 100 reached');
  });
});