Open native REPL in active group when no tabs are open

src/client/repl/replCommandHandler.ts

@@ -7,20 +7,26 @@ import {
     NotebookEdit,
     WorkspaceEdit,
     Uri,
+    window,
+    TabGroup,
 } from 'vscode';
 import { getExistingReplViewColumn, getTabNameForUri } from './replUtils';
 import { showNotebookDocument } from '../common/vscodeApis/windowApis';
 import { openNotebookDocument, applyEdit } from '../common/vscodeApis/workspaceApis';
 import { executeCommand } from '../common/vscodeApis/commandApis';
 
+export function getNewReplViewColumn(tabGroups: readonly TabGroup[]): ViewColumn {
+    return tabGroups.some((tabGroup) => tabGroup.tabs.length > 0) ? ViewColumn.Beside : ViewColumn.Active;
+}
+
 /**
  * Function that opens/show REPL using IW UI.
  */
 export async function openInteractiveREPL(
     notebookDocument: NotebookDocument | Uri | undefined,
     preserveFocus: boolean = true,
 ): Promise<{ notebookEditor: NotebookEditor; documentCreated: boolean } | undefined> {
-    let viewColumn = ViewColumn.Beside;
+    let viewColumn = getNewReplViewColumn(window.tabGroups.all);
     let alreadyExists = false;
     if (notebookDocument instanceof Uri) {
         // Case where NotebookDocument is undefined, but workspace mementoURI exists.

src/test/repl/replCommandHandler.unit.test.ts

@@ -0,0 +1,21 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+import { expect } from 'chai';
+import { TabGroup, ViewColumn } from 'vscode';
+import { getNewReplViewColumn } from '../../client/repl/replCommandHandler';
+
+suite('REPL - command handler', () => {
+    test('opens a new REPL in the active group when no tabs are open', () => {
+        const emptyTabGroup = ({ tabs: [] } as unknown) as TabGroup;
+
+        expect(getNewReplViewColumn([emptyTabGroup])).to.equal(ViewColumn.Active);
+    });
+
+    test('opens a new REPL beside existing tabs', () => {
+        const emptyTabGroup = ({ tabs: [] } as unknown) as TabGroup;
+        const tabGroupWithOpenTab = ({ tabs: [{}] } as unknown) as TabGroup;
+
+        expect(getNewReplViewColumn([emptyTabGroup, tabGroupWithOpenTab])).to.equal(ViewColumn.Beside);
+    });
+});