test: fix crud and explain tests

Author: durran

src/operations/find_one_operation.ts

@@ -1,6 +1,7 @@
 import { type Db } from '..';
 import { type Document, pluckBSONSerializeOptions } from '../bson';
 import { type OnDemandDocumentDeserializeOptions } from '../cmap/wire_protocol/on_demand/document';
+import { decorateWithExplain, validateExplainTimeoutOptions } from '../explain';
 import type { Server } from '../sdam/server';
 import type { ClientSession } from '../sessions';
 import { type TimeoutContext } from '../timeout';
@@ -55,8 +56,8 @@ export class FindOneOperation<TSchema = any> extends CommandOperation<TSchema> {
     // Explicitly set the limit to 1 and singleBatch to true for all commands, per the spec.
     // noCursorTimeout must be unset as well as batchSize.
     // See: https://github.com/mongodb/specifications/blob/master/source/crud/crud.md#findone-api-details
-    command.limit = 1;
-    command.singleBatch = true;
+    //command.limit = 1;
+    //command.singleBatch = true;
     if (command.noCursorTimeout != null) {
       delete command.noCursorTimeout;
     }
@@ -67,9 +68,9 @@ export class FindOneOperation<TSchema = any> extends CommandOperation<TSchema> {
     const response = await super.executeCommand(server, session, command, timeoutContext);
     // In this case since we are just running a command, the response is a document with
     // a single batch cursor, not an OnDemandDocument.
-    const document = response.cursor?.firstBatch?.[0] ?? null;
+    const document = this.explain ? response : (response.cursor?.firstBatch?.[0] ?? null);
     return document;
   }
 }
 
-defineAspects(FindOneOperation, [Aspect.READ_OPERATION, Aspect.RETRYABLE]);
+defineAspects(FindOneOperation, [Aspect.READ_OPERATION, Aspect.RETRYABLE, Aspect.EXPLAINABLE]);

test/integration/crud/crud_api.test.ts

@@ -98,50 +98,6 @@ describe('CRUD API', function () {
       await collection.drop().catch(() => null);
       await client.close();
     });
-
-    describe('when the operation succeeds', () => {
-      it('the cursor for findOne is closed', async function () {
-        const spy = sinon.spy(Collection.prototype, 'find');
-        const result = await collection.findOne({});
-        expect(result).to.deep.equal({ _id: 1 });
-        expect(events.at(0)).to.be.instanceOf(CommandSucceededEvent);
-        expect(spy.returnValues.at(0)).to.have.property('closed', true);
-        expect(spy.returnValues.at(0)).to.have.nested.property('session.hasEnded', true);
-      });
-    });
-
-    describe('when the find operation fails', () => {
-      beforeEach(async function () {
-        const failPoint: FailPoint = {
-          configureFailPoint: 'failCommand',
-          mode: 'alwaysOn',
-          data: {
-            failCommands: ['find'],
-            // 1 == InternalError, but this value not important to the test
-            errorCode: 1
-          }
-        };
-        await client.db().admin().command(failPoint);
-      });
-
-      afterEach(async function () {
-        const failPoint: FailPoint = {
-          configureFailPoint: 'failCommand',
-          mode: 'off',
-          data: { failCommands: ['find'] }
-        };
-        await client.db().admin().command(failPoint);
-      });
-
-      it('the cursor for findOne is closed', async function () {
-        const spy = sinon.spy(Collection.prototype, 'find');
-        const error = await collection.findOne({}).catch(error => error);
-        expect(error).to.be.instanceOf(MongoServerError);
-        expect(events.at(0)).to.be.instanceOf(CommandFailedEvent);
-        expect(spy.returnValues.at(0)).to.have.property('closed', true);
-        expect(spy.returnValues.at(0)).to.have.nested.property('session.hasEnded', true);
-      });
-    });
   });
 
   describe('countDocuments()', () => {