chore: remove dead code

Author: durran

src/cmap/wire_protocol/responses.ts

@@ -391,9 +391,3 @@ export class ClientBulkWriteCursorResponse extends CursorResponse {
     return this.get('writeConcernError', BSONType.object, false);
   }
 }
-
-export class ExplainResponse extends MongoDBResponse {
-  get queryPlanner() {
-    return this.get('queryPlanner', BSONType.object, false);
-  }
-}

src/operations/find.ts

@@ -152,11 +152,7 @@ export class FindOperation extends CommandOperation<CursorResponse> {
   }
 }
 
-export function makeFindCommand(
-  ns: MongoDBNamespace,
-  filter: Document,
-  options: FindOptions
-): Document {
+function makeFindCommand(ns: MongoDBNamespace, filter: Document, options: FindOptions): Document {
   const findCommand: Document = {
     find: ns.collection,
     filter

src/operations/find_one.ts

@@ -98,6 +98,50 @@ 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()', () => {