fix(vscode): add project adds the chosen folder to the workspace

packages/vscode/src/bridge-system-runtime.test.js

@@ -1,6 +1,13 @@
 import { beforeEach, describe, expect, mock, test } from 'bun:test';
 
 const executeCommand = mock(async () => undefined);
+const updateWorkspaceFolders = mock(async (start, deleteCount, ...foldersToAdd) => {
+  for (const folder of foldersToAdd) {
+    currentWorkspaceFolders = [...currentWorkspaceFolders, { name: folder.uri.fsPath.split('/').pop(), uri: folder.uri }];
+  }
+  return true;
+});
+let currentWorkspaceFolders = [];
 
 class Position {
   constructor(line, character) {
@@ -19,7 +26,10 @@ class Range {
 mock.module('vscode', () => ({
   commands: { executeCommand },
   workspace: {
-    workspaceFolders: [],
+    get workspaceFolders() {
+      return currentWorkspaceFolders;
+    },
+    updateWorkspaceFolders,
   },
   Uri: {
     file: (fsPath) => ({ scheme: 'file', fsPath }),
@@ -65,6 +75,8 @@ const deps = {
 describe('VS Code system bridge editor:openFile', () => {
   beforeEach(() => {
     executeCommand.mockClear();
+    updateWorkspaceFolders.mockClear();
+    currentWorkspaceFolders = [];
   });
 
   test('uses vscode.open so VS Code can select the notebook editor', async () => {
@@ -97,3 +109,113 @@ describe('VS Code system bridge editor:openFile', () => {
     );
   });
 });
+
+describe('VS Code system bridge api:workspace:addFolder', () => {
+  beforeEach(() => {
+    updateWorkspaceFolders.mockClear();
+    currentWorkspaceFolders = [];
+  });
+
+  test('adds a folder to the workspace and returns the folder list', async () => {
+    currentWorkspaceFolders = [{ name: 'project-one', uri: { fsPath: '/workspace/project-one' } }];
+
+    const response = await handleSystemBridgeMessage({
+      id: 'add-folder',
+      type: 'api:workspace:addFolder',
+      payload: { path: '/home/user/my-project' },
+    }, undefined, deps);
+
+    expect(response).toEqual({
+      id: 'add-folder',
+      type: 'api:workspace:addFolder',
+      success: true,
+      data: {
+        workspaceFolders: [
+          { name: 'my-project', path: '/home/user/my-project' },
+          { name: 'project-one', path: '/workspace/project-one' },
+        ],
+      },
+    });
+    expect(updateWorkspaceFolders).toHaveBeenCalledWith(
+      1,
+      null,
+      { uri: { scheme: 'file', fsPath: '/home/user/my-project' } },
+    );
+  });
+
+  test('does not duplicate an already-open workspace folder', async () => {
+    currentWorkspaceFolders = [{ name: 'project-one', uri: { fsPath: '/workspace/project-one' } }];
+
+    const response = await handleSystemBridgeMessage({
+      id: 'add-existing',
+      type: 'api:workspace:addFolder',
+      payload: { path: '/workspace/project-one' },
+    }, undefined, deps);
+
+    expect(response).toEqual({
+      id: 'add-existing',
+      type: 'api:workspace:addFolder',
+      success: true,
+      data: {
+        workspaceFolders: [{ name: 'project-one', path: '/workspace/project-one' }],
+      },
+    });
+    expect(updateWorkspaceFolders).not.toHaveBeenCalled();
+  });
+
+  test('returns an error when VS Code rejects the folder add', async () => {
+    updateWorkspaceFolders.mockResolvedValue(false);
+
+    const response = await handleSystemBridgeMessage({
+      id: 'add-rejected',
+      type: 'api:workspace:addFolder',
+      payload: { path: '/home/user/other' },
+    }, undefined, deps);
+
+    expect(response).toEqual({
+      id: 'add-rejected',
+      type: 'api:workspace:addFolder',
+      success: false,
+      error: 'Failed to add workspace folder',
+    });
+  });
+
+  test('dedupes an already-open folder with a lowercase Windows drive letter', async () => {
+    // VS Code reports workspace folder paths with lowercase drive letters
+    // (d:\...), while the bridge normalizes the incoming path to uppercase
+    // (D:\...). The comparison must normalize both sides.
+    currentWorkspaceFolders = [{ name: 'project-one', uri: { fsPath: 'd:\\work\\project-one' } }];
+
+    const response = await handleSystemBridgeMessage({
+      id: 'add-win-dedupe',
+      type: 'api:workspace:addFolder',
+      payload: { path: 'D:\\work\\project-one' },
+    }, undefined, deps);
+
+    expect(response).toEqual({
+      id: 'add-win-dedupe',
+      type: 'api:workspace:addFolder',
+      success: true,
+      data: {
+        workspaceFolders: [{ name: 'project-one', path: 'D:\\work\\project-one' }],
+      },
+    });
+    expect(updateWorkspaceFolders).not.toHaveBeenCalled();
+  });
+
+  test('rejects a missing path', async () => {
+    const response = await handleSystemBridgeMessage({
+      id: 'add-missing',
+      type: 'api:workspace:addFolder',
+      payload: {},
+    }, undefined, deps);
+
+    expect(response).toEqual({
+      id: 'add-missing',
+      type: 'api:workspace:addFolder',
+      success: false,
+      error: 'Directory path is required',
+    });
+    expect(updateWorkspaceFolders).not.toHaveBeenCalled();
+  });
+});