feat(shell-api): reset current cursor when db changes or auths MONGOSH-13

Reset the current cursor on:
- Assignment to `db`
- `db.auth()`
- `db.logout()`

Author: addaleax

packages/cli-repl/test/e2e-auth.spec.ts

@@ -717,7 +717,7 @@ describe('Auth e2e', function() {
       afterEach(async() => {
         db.command({ dropAllUsersFromDatabase: 1 });
       });
-      describe('auth', async() => {
+      describe('auth', () => {
         it('logs in with simple user/pwd', async() => {
           shell.writeInputLine(`use ${dbName}`);
           shell.writeInputLine(
@@ -796,7 +796,7 @@ describe('Auth e2e', function() {
           });
         });
       });
-      describe('logout', async() => {
+      describe('logout', () => {
         it('logs out after authenticating', async() => {
           shell.writeInputLine(`use ${dbName}`);
           shell.writeInputLine(
@@ -826,6 +826,35 @@ describe('Auth e2e', function() {
           shell.assertNoErrors();
         });
       });
+      describe('resetting current cursor', () => {
+        beforeEach(async() => {
+          await db.collection('test').insertMany(
+            [...Array(200).keys()].map(i => ({ i }))
+          );
+        });
+        it('is reset after auth, db reassign and logout', async() => {
+          await shell.executeLine(`use ${dbName}`);
+          expect(await shell.executeLine('db.test.find()')).to.include('i: 10');
+          expect(await shell.executeLine('it')).to.include('i: 30');
+
+          expect(await shell.executeLine('db.auth("anna", "pwd")')).to.include('ok: 1');
+          expect(await shell.executeLine('it')).to.include('no cursor');
+          expect(await shell.executeLine('db.test.find()')).to.include('i: 10');
+          expect(await shell.executeLine('it')).to.include('i: 30');
+
+          expect(await shell.executeLine(`db = db.getSiblingDB("${dbName}")`)).to.include(`${dbName}\n`);
+          expect(await shell.executeLine('it')).to.include('no cursor');
+          expect(await shell.executeLine('db.test.find()')).to.include('i: 10');
+          expect(await shell.executeLine('it')).to.include('i: 30');
+
+          expect(await shell.executeLine('db.logout()')).to.include('ok: 1');
+          expect(await shell.executeLine('it')).to.include('no cursor');
+          expect(await shell.executeLine('db.test.find()')).to.include('i: 10');
+          expect(await shell.executeLine('it')).to.include('i: 30');
+
+          shell.assertNoErrors();
+        });
+      });
     });
   });
   describe('with options in URI on on the command line', () => {

packages/shell-api/src/database.ts

@@ -452,6 +452,7 @@ export default class Database extends ShellApiWithMongoClass {
   @apiVersions([])
   async logout(): Promise<Document> {
     this._emitDatabaseApiCall('logout', {});
+    this._mongo._internalState.currentCursor = null;
     return await this._runCommand({ logout: 1 });
   }
 
@@ -516,6 +517,7 @@ export default class Database extends ShellApiWithMongoClass {
       );
     }
     authDoc.authDb = this._name;
+    this._mongo._internalState.currentCursor = null;
     return await this._mongo._serviceProvider.authenticate(authDoc);
   }
 

packages/shell-api/src/shell-internal-state.ts

@@ -174,6 +174,7 @@ export default class ShellInternalState {
     // Pre-fetch for autocompletion.
     this.currentDb._getCollectionNamesForCompletion().catch(err => this.messageBus.emit('mongosh:error', err));
     this.currentDb._mongo._getDatabaseNamesForCompletion().catch(err => this.messageBus.emit('mongosh:error', err));
+    this.currentCursor = null;
     return newDb;
   }