token-cache.test.js

const Promise = require('bluebird');
const tokenCache = require('./token-cache');

describe('cache', () => {
  test('should use the maxAge setting', () => {
    const getToken = jest
      .fn()
      .mockReturnValueOnce(Promise.resolve('token1'))
      .mockReturnValueOnce(Promise.resolve('token2'));

    const cache = tokenCache(getToken, {
      maxAge: 100
    });

    return cache()
      .then((token) => {
        expect(token).toEqual('token1');
      })
      .then(() => Promise.delay(50))
      .then(() => cache())
      .then((token) => {
        expect(token).toEqual('token1');
      })
      .then(() => Promise.delay(100))
      .then(() => cache())
      .then((token) => {
        expect(token).toEqual('token2');
      });
  });

  test('should use the getMaxAge setting', () => {
    const getToken = jest
      .fn()
      .mockReturnValueOnce(
        Promise.resolve({ access_token: 'token1', expires_in: 2 })
      )
      .mockReturnValueOnce(
        Promise.resolve({ access_token: 'token2', expires_in: 5 })
      );

    const cache = tokenCache(getToken, {
      getMaxAge: (token) => token.expires_in * 1000
    });

    return cache()
      .then((token) => {
        expect(token.access_token).toEqual('token1');
      })
      .then(() => Promise.delay(1000))
      .then(() => cache())
      .then((token) => {
        expect(token.access_token).toEqual('token1');
      })
      .then(() => Promise.delay(2000))
      .then(() => cache())
      .then((token) => {
        expect(token.access_token).toEqual('token2');
      });
  });

  test('should support reset', () => {
    const getToken = jest
      .fn()
      .mockReturnValueOnce(
        Promise.resolve({ access_token: 'token1', expires_in: 5 })
      )
      .mockReturnValueOnce(
        Promise.resolve({ access_token: 'token2', expires_in: 10 })
      );

    const cache = tokenCache(getToken, {
      getMaxAge: (token) => token.expires_in * 1000
    });

    return cache()
      .then((config) => {
        expect(config.access_token).toEqual('token1');
        cache.reset();
      })
      .then(() => cache())
      .then((config) => {
        expect(config.access_token).toEqual('token2');
      });
  });

  test('should not make concurrent calls for a cache miss', () => {
    const getToken = jest
      .fn()
      .mockReturnValueOnce(
        Promise.delay(50).then(() => Promise.resolve('token1'))
      );
    const cache = tokenCache(getToken, {
      maxAge: 100
    });

    return Promise.all([cache(), cache()]).spread((token1, token2) => {
      expect(token1).toEqual('token1');
      expect(token2).toEqual('token1');
    });
  });

  test('should handle errors correctly', () => {
    const getToken = () => Promise.reject(new Error('unable to fetch token'));
    const cache = tokenCache(getToken, {
      maxAge: 100
    });

    return cache().catch((err) => {
      expect(err.message).toEqual('unable to fetch token');
    });
  });
});