fix(vscode-ide-companion): add missing activate() Disposables

[parveshsaini]

Summary

activate() in the VS Code companion extension wraps two groups of
registrations in an extra pair of parentheses, which turns each group into a
JavaScript comma expression instead of separate arguments to
context.subscriptions.push(...). A comma expression evaluates both operands
but yields only the last one, so the first registration in each group runs
but its Disposable is never pushed onto context.subscriptions — and is
therefore never disposed on deactivation.

Two Disposables leak today:

• the gemini.diff.accept command, and
• the onDidChangeWorkspaceFolders listener.

Impact:

• On deactivation/reload within the same extension host (e.g. an extension
  update), gemini.diff.accept stays registered. Re-activation then throws
  command 'gemini.diff.accept' already exists.
• The onDidChangeWorkspaceFolders listener is never torn down, so a stale
  listener keeps calling ideServer.syncEnvVars() against an IDEServer that
  has already been stopped.

Details

The two offending groups in packages/vscode-ide-companion/src/extension.ts:

// group 1
(vscode.commands.registerCommand('gemini.diff.accept', ...),
 vscode.commands.registerCommand('gemini.diff.cancel', ...)),

// group 2
(vscode.workspace.onDidChangeWorkspaceFolders(...),
 vscode.workspace.onDidGrantWorkspaceTrust(...)),

The surrounding registrations in the same two push() calls already use the
flat one-argument-per-Disposable style, which is what makes the two
parenthesized groups stand out as unintended. The fix removes the stray ( / )
around each group so every registration is its own argument to push().

This is a platform-independent defect (JavaScript comma-operator semantics),
present since the companion extension was introduced.

Related Issues

Closes #27790

How to Validate

npm test -w packages/vscode-ide-companion -- src/extension.test.ts

This PR adds a regression test, adds every registered disposable to context.subscriptions, to extension.test.ts. The existing vscode mock
returned undefined from registerCommand / the workspace listeners, which is
why the leak was invisible to the suite; the mock now returns a tagged
Disposable so the test can assert what actually lands in
context.subscriptions.

• Without the fix, the new test fails — context.subscriptions is missing
  gemini.diff.accept and onDidChangeWorkspaceFolders
  (expected [ 'onDidCloseTextDocument', …(5) ] to include 'gemini.diff.accept');
  the suite reports 1 failed | 11 passed.
• With the fix, all four registrations (gemini.diff.accept,
  gemini.diff.cancel, onDidChangeWorkspaceFolders,
  onDidGrantWorkspaceTrust) are present and the suite reports 12 passed.

Pre-Merge Checklist

• Updated relevant documentation and README (if needed)
• Added/updated tests (if needed)
• Noted breaking changes (if any)
• Validated on required platforms/methods:
  • MacOS
    • npm run
    • npx
    • Docker
    • Podman
    • Seatbelt
  • Windows
    • npm run
    • npx
    • Docker
  • Linux
    • npm run
    • npx
    • Docker

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a bug in the VS Code companion extension where certain command and workspace event registrations were failing to be disposed of properly due to incorrect syntax. By removing unintended comma expressions, the extension now correctly tracks these Disposables, preventing memory leaks and command registration conflicts during extension reloads.

Highlights

• Fixed Disposable Leaks: Removed erroneous parentheses that created JavaScript comma expressions, ensuring all command and workspace event registrations are correctly pushed to context.subscriptions.
• Regression Testing: Updated the VS Code mock in the test suite to return tagged Disposables and added a new test case to verify that all expected registrations are successfully added to the subscription list.

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[github-actions]

📊 PR Size: size/M

• Lines changed: 50
• Additions: +39
• Deletions: -11
• Files changed: 2

[gemini-code-assist]

Code Review

This pull request cleans up redundant parentheses in the VS Code extension activation code and updates the test suite to verify that registered disposables are correctly added to the context subscriptions. Feedback on the changes highlights a resource leak in the tests, where calling activate(context) starts an Express server that is never cleaned up, and recommends adding a deactivate() call in afterEach to prevent hanging test processes.

[gemini-code-assist]

Resource Leak in Tests

Calling activate(context) starts an Express server on a random port via ideServer.start(context). Because deactivate() is never called in afterEach (or within the tests), these HTTP servers and their associated sockets are leaked for every test that executes activate(context). This can lead to port exhaustion, memory leaks, and hanging test processes, especially in CI or watch mode.

To resolve this, please import deactivate from ./extension.js and call it in afterEach to ensure proper cleanup:

import { activate, deactivate } from './extension.js';

// ...

afterEach(async () => {
  await deactivate();
  vi.restoreAllMocks();
});

[parveshsaini]

Added deactivate() to afterEach to tear down the IDE server, plus a dispose mock on the output channel so cleanup doesn't throw. All 12 tests still pass ✅