Code OSS Dev - Launch + Debug

You're working on VS Code itself and you want to:

1. Launch a Code OSS build from sources that is already signed in (Copilot, GitHub, etc.) so chat / agent flows work end-to-end.
2. Drive it with @playwright/cli over CDP (UI automation).
3. Optionally attach a debugger via dap-cli to set breakpoints in the renderer, extension host, or main process.
4. Run multiple instances at once without port conflicts.

This skill provides a launcher that clones an authenticated user-data-dir to a throwaway temp folder, picks free ports for every debug surface, and prints them as JSON so you can pick them up programmatically.

The clone is slim: workspace storage, browser caches, file history, cached VSIX backups, and old logs are excluded by default. Auth tokens themselves live in the OS keychain (shared automatically) plus small files inside User/globalStorage - both of which are preserved.

Prerequisites

• macOS or Linux. The launcher is a bash script and depends on rsync, curl, nohup, and Node on PATH. The example caller snippets below also use jq (parse the JSON output) and lsof (kill-by-port fallback) — install those if you plan to use them, but the launcher itself does not require them.
• A VS Code checkout with node_modules/ installed (npm install if missing — do not symlink from a sibling worktree; that breaks builds in subtle ways).
• A VS Code checkout with sources built. Run npm run compile once (one-shot) or npm run watch for incremental rebuilds. Both build the full client and all built-in extensions under extensions/. You must build the full product to run successfully, building just the client is not enough.
• An authenticated Code OSS profile to seed from. By default the launcher uses ~/.vscode-oss-dev, which is the user-data-dir the repo's launch.json configs use - if the user has ever signed in to Copilot in a dev build, this should work. Only pass --source-user-data-dir <path> (or set $CODE_OSS_DEV_AUTHED_USER_DATA_DIR) when you specifically want to seed from a different profile (e.g. your regular ~/Library/Application Support/Code install).
  • If Code OSS launches and needs a sign-in, don't give up! Use the questions tool to ask the user to sign in.
• @playwright/cli available (it's a devDependency in the vscode repo - npm install then use npx @playwright/cli).
• For debugger work: dap-cli on PATH. If debugger support would be useful but the dap-cli skill is not present, prompt the user to install it from https://github.com/roblourens/dap-cli.
• CSS selectors are internal implementation details. If a selector-based eval stops working, take a fresh snapshot, inspect the current DOM, and update the selector rather than assuming an old one still applies.

The launcher copies the source profile to a temp dir and never mutates the original. Each launch gets its own isolated --user-data-dir and --extensions-dir.

The launcher always sets files.simpleDialog.enable: true in the launched profile's User/settings.json. This is required for automation: VS Code's native OS file dialogs cannot be driven via @playwright/cli over CDP and are completely unreachable over SSH on headless macOS. The simple (quick-input) dialog can be navigated with press and clipboard paste. The override is per-launch and only affects throwaway profiles.

Launch

The launcher script lives next to this SKILL.md at scripts/launch.sh. Resolve it relative to wherever this skill file is installed - do not hardcode an absolute path.

# LAUNCH=<dir-of-this-SKILL.md>/scripts/launch.sh
"$LAUNCH"                                    # default: workbench
"$LAUNCH" --agents                           # Agents window
"$LAUNCH" -- <workspace-path>                # forward extra args to code.sh
"$LAUNCH" --source-user-data-dir <path>      # pick a specific authed profile

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