text: // Licensed under the Apache License, Version 2.0 (the 'License'); you may not
  // use this file except in compliance with the License. You may obtain a copy of
  // the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an 'AS IS' BASIS, WITHOUT
  // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  // License for the specific language governing permissions and limitations under
  // the License.
  
  const Nano = require('..')
  const COUCH_URL = 'http://localhost:5984'
  const nano = Nano(COUCH_URL)
  const nock = require('nock')
  const response = {
    results: [
      {
        seq: '1-nC1J',
        id: 'c42ddf1272c7d05b2dc45b6962000b10',
        changes: [
          {
            rev: '1-23202479633c2b380f79507a776743d5'
          }
        ]
      }
    ],
    last_seq: '1-C1J',
    pending: 0
  }
  const errResponse = {
    error: 'not_found',
    reason: 'Database does not exist.'
  }
  
  afterEach(() => {
    nock.cleanAll()
  })
  
  test('should be able to fetch the changes - GET /db/_changes - nano.db.changes', async () => {
    // mocks
    const scope = nock(COUCH_URL)
      .get('/db/_changes')
      .reply(200, response)
  
    // test GET /db/_changes
    const p = await nano.db.changes('db')
    expect(p).toStrictEqual(response)
    expect(scope.isDone()).toBe(true)
  })
  
  test('should be able to fetch the changes with opts - GET /db/_changes - nano.db.changes', async () => {
    // mocks
    const opts = { include_docs: true, feed: 'continuous' }
    const scope = nock(COUCH_URL)
      .get('/db/_changes')
      .query(opts)
      .reply(200, response)
  
    // test GET /db/_changes
    const p = await nano.db.changes('db', opts)
    expect(p).toStrictEqual(response)
    expect(scope.isDone()).toBe(true)
  })
  
  test('should be able to handle a missing database - GET /db/_changes - nano.db.changes', async () => {
    // mocks
    const scope = nock(COUCH_URL)
      .get('/db/_changes')
      .reply(404, errResponse)
  
    // test GET /db/_changes
    await expect(nano.db.changes('db')).rejects.toThrow('Database does not exist')
    expect(scope.isDone()).toBe(true)
  })
  
  test('should not attempt invalid parameters - nano.db.changes', async () => {
    await expect(nano.db.changes()).rejects.toThrowError('Invalid parameters')
    await expect(nano.db.changes('')).rejects.toThrowError('Invalid parameters')
  })
  
  test('should detect missing parameters (callback) - nano.db.changes', () => {
    return new Promise((resolve, reject) => {
      nano.db.changes(undefined, undefined, (err, data) => {
        expect(err).not.toBeNull()
        resolve()
      })
    })
  })
  
  test('should be able to fetch the changes from db.changes - GET /db/_changes - db.changes', async () => {
    // mocks
    const scope = nock(COUCH_URL)
      .get('/db/_changes')
      .reply(200, response)
  
    // test GET /db/_changes
    const db = nano.db.use('db')
    const p = await db.changes()
    expect(p).toStrictEqual(response)
    expect(scope.isDone()).toBe(true)
  })
  