Silences warnings from mongodb client (#5025)

* Silences warnings from mongodb client

* Update count, delete and finds to recommended implementations

* With new parser, readPref will be null by default

* Update flaky specs wih async/await style

* Adds gridstore adapter spec

* Use GridFSBucketStorage adapter

spec/GridFSBucketStorageAdapter.spec.js

@@ -0,0 +1,67 @@
+const GridStoreAdapter = require('../lib/Adapters/Files/GridStoreAdapter')
+  .GridStoreAdapter;
+const GridFSBucketAdapter = require('../lib/Adapters/Files/GridFSBucketAdapter')
+  .GridFSBucketAdapter;
+const { randomString } = require('../lib/cryptoUtils');
+const databaseURI = 'mongodb://localhost:27017/parse';
+
+async function expectMissingFile(gfsAdapter, name) {
+  try {
+    await gfsAdapter.getFileData(name);
+    fail('should have thrown');
+  } catch (e) {
+    expect(e.message).toEqual('FileNotFound: file myFileName was not found');
+  }
+}
+
+describe('GridFSBucket and GridStore interop', () => {
+  beforeEach(async () => {
+    const gsAdapter = new GridStoreAdapter(databaseURI);
+    const db = await gsAdapter._connect();
+    db.dropDatabase();
+  });
+
+  it('a file created in GridStore should be available in GridFS', async () => {
+    const gsAdapter = new GridStoreAdapter(databaseURI);
+    const gfsAdapter = new GridFSBucketAdapter(databaseURI);
+    await expectMissingFile(gfsAdapter, 'myFileName');
+    const originalString = 'abcdefghi';
+    await gsAdapter.createFile('myFileName', originalString);
+    const gsResult = await gsAdapter.getFileData('myFileName');
+    expect(gsResult.toString('utf8')).toBe(originalString);
+    const gfsResult = await gfsAdapter.getFileData('myFileName');
+    expect(gfsResult.toString('utf8')).toBe(originalString);
+  });
+
+  it('properly fetches a large file from GridFS', async () => {
+    const gfsAdapter = new GridFSBucketAdapter(databaseURI);
+    const twoMegabytesFile = randomString(2048 * 1024);
+    await gfsAdapter.createFile('myFileName', twoMegabytesFile);
+    const gfsResult = await gfsAdapter.getFileData('myFileName');
+    expect(gfsResult.toString('utf8')).toBe(twoMegabytesFile);
+  });
+
+  it(
+    'properly deletes a file from GridFS',
+    async () => {
+      const gfsAdapter = new GridFSBucketAdapter(databaseURI);
+      await gfsAdapter.createFile('myFileName', 'a simple file');
+      await gfsAdapter.deleteFile('myFileName');
+      await expectMissingFile(gfsAdapter, 'myFileName');
+    },
+    1000000
+  );
+
+  it('properly overrides files', async () => {
+    const gfsAdapter = new GridFSBucketAdapter(databaseURI);
+    await gfsAdapter.createFile('myFileName', 'a simple file');
+    await gfsAdapter.createFile('myFileName', 'an overrided simple file');
+    const data = await gfsAdapter.getFileData('myFileName');
+    expect(data.toString('utf8')).toBe('an overrided simple file');
+    const bucket = await gfsAdapter._getBucket();
+    const documents = await bucket.find({ filename: 'myFileName' }).toArray();
+    expect(documents.length).toBe(2);
+    await gfsAdapter.deleteFile('myFileName');
+    await expectMissingFile(gfsAdapter, 'myFileName');
+  });
+});