CommunitySolidServer/test/unit/util/locking/FileSystemResourceLocker.test.ts

import { readdir } from 'fs-extra';
import { InternalServerError } from '../../../../src/util/errors/InternalServerError';
import { FileSystemResourceLocker } from '../../../../src/util/locking/FileSystemResourceLocker';

const lockFolder = './.internal/locks/';

describe('A FileSystemResourceLocker', (): void => {
  let locker: FileSystemResourceLocker;
  const identifier = { path: 'http://test.com/foo' };

  beforeEach(async(): Promise<void> => {
    locker = new FileSystemResourceLocker({ attemptSettings: { retryCount: 19, retryDelay: 100 }});
  });

  afterEach(async(): Promise<void> => {
    try {
      // Release to be sure
      await locker.release(identifier);
    } catch {
      // Do nothing
    }
  });

  afterAll(async(): Promise<void> => {
    await locker.finalize();
  });

  it('can lock and unlock a resource.', async(): Promise<void> => {
    await expect(locker.acquire(identifier)).resolves.toBeUndefined();
    await expect(locker.release(identifier)).resolves.toBeUndefined();
  });

  it('can lock and unlock a resource with a locker with indefinite retry.', async(): Promise<void> => {
    const locker2 = new FileSystemResourceLocker({ attemptSettings: { retryCount: -1 }});
    await expect(locker2.acquire(identifier)).resolves.toBeUndefined();
    await expect(locker2.release(identifier)).resolves.toBeUndefined();
    await locker2.finalize();
  });

  it('can lock a resource again after it was unlocked.', async(): Promise<void> => {
    await expect(locker.acquire(identifier)).resolves.toBeUndefined();
    await expect(locker.release(identifier)).resolves.toBeUndefined();
    await expect(locker.acquire(identifier)).resolves.toBeUndefined();
  });

  it('errors when unlocking a resource that was not locked.', async(): Promise<void> => {
    await expect(locker.acquire(identifier)).resolves.toBeUndefined();
    await expect(locker.release(identifier)).resolves.toBeUndefined();
    await expect(locker.release(identifier)).rejects.toThrow(InternalServerError);
    await expect(locker.release(identifier)).rejects.toThrow('Lock is not acquired/owned by you');
  });

  it('errors when max retries has been reached.', async(): Promise<void> => {
    await locker.acquire(identifier);
    await expect(locker.acquire(identifier)).rejects
      .toThrow(
        /Error trying to acquire lock for .*\. The operation did not succeed after the set maximum of tries \(\d+\)\./u,
      );
    await locker.release(identifier);
  });

  it('blocks lock acquisition until they are released.', async(): Promise<void> => {
    const results: number[] = [];
    const lock1 = locker.acquire(identifier);
    const lock2 = locker.acquire(identifier);
    const lock3 = locker.acquire(identifier);

    // Note the different order of calls
    const prom2 = lock2.then(async(): Promise<void> => {
      results.push(2);
      return locker.release(identifier);
    });
    const prom3 = lock3.then(async(): Promise<void> => {
      results.push(3);
      return locker.release(identifier);
    });
    const prom1 = lock1.then(async(): Promise<void> => {
      results.push(1);
      return locker.release(identifier);
    });
    await Promise.all([ prom2, prom3, prom1 ]);
    expect(results[0]).toBe(1);
    expect(results).toContain(2);
    expect(results).toContain(3);
  });

  it('can acquire different keys simultaneously.', async(): Promise<void> => {
    const results: number[] = [];
    const lock1 = locker.acquire({ path: 'path1' });
    const lock2 = locker.acquire({ path: 'path2' });
    const lock3 = locker.acquire({ path: 'path3' });
    await lock2.then(async(): Promise<void> => {
      results.push(2);
      return locker.release({ path: 'path2' });
    });
    await lock3.then(async(): Promise<void> => {
      results.push(3);
      return locker.release({ path: 'path3' });
    });
    await lock1.then(async(): Promise<void> => {
      results.push(1);
      return locker.release({ path: 'path1' });
    });
    expect(results).toEqual([ 2, 3, 1 ]);
  });

  it('throws an error when #tryFn() throws an error.', async(): Promise<void> => {
    await locker.acquire(identifier);
    await expect(locker.acquire(identifier)).rejects.toThrow(InternalServerError);
  });

  it('clears the files in de lock directory after calling finalize.', async(): Promise<void> => {
    await locker.acquire(identifier);
    await expect(readdir(lockFolder)).resolves.toHaveLength(1);
    await locker.finalize();
    await expect(readdir(lockFolder)).rejects.toThrow();
  });

  it('can create a locker with default AttemptSettings.', async(): Promise<void> => {
    expect((): FileSystemResourceLocker => new FileSystemResourceLocker()).not.toThrow();
  });
});