deal with no connection

Author: lerouxb

packages/mongodb-ts-autocomplete/src/autocompleter.spec.ts

@@ -49,6 +49,17 @@ describe('MongoDBAutocompleter', function () {
     });
   });
 
+  it('deals with no connection', async function () {
+    autocompleterContext.currentDatabaseAndConnection = () => {
+      const error = new Error('No connection');
+      error.name = 'MongoshInvalidInputError';
+      throw error;
+    };
+
+    const completions = await autocompleter.autocomplete('db.');
+    expect(completions).to.deep.equal([]);
+  });
+
   it('does not leak the bson package', async function () {
     const completions = await autocompleter.autocomplete('bson.');
     expect(completions).to.deep.equal([]);

packages/mongodb-ts-autocomplete/src/autocompleter.ts

@@ -202,8 +202,21 @@ declare global {
   }
 
   async autocomplete(code: string): Promise<AutoCompletion[]> {
-    const { connectionId, databaseName } =
-      this.context.currentDatabaseAndConnection();
+    let connectionId: string;
+    let databaseName: string;
+
+    // If there's no known connection, currentDatabaseAndConnection() will
+    // error, but we won't be able to generate types for a connection, db
+    // object, etc, anyway. So just return no results in that case.
+    try {
+      ({ connectionId, databaseName } =
+        this.context.currentDatabaseAndConnection());
+    } catch (err: any) {
+      if (err.name === 'MongoshInvalidInputError') {
+        return [];
+      }
+      throw err;
+    }
 
     const tsAst = compileSourceFile(code);
     const collectionName = inferCollectionNameFromFunctionCall(tsAst) || 'test';