Editor Setup

Installs the editors, makes their CLI launchers work, and applies a small, defensible settings baseline. Default pair: VS Code (largest ecosystem) and Cursor (AI-first fork — imports VS Code's settings, so they stay in sync at install time); Zed (fast native) on request. Skip either half of the pair if the user wants only one.

When NOT to use

• Terminal emulators (Ghostty/iTerm2/Warp) → mac-dev-apps
• JetBrains IDEs → install jetbrains-toolbox cask via mac-dev-apps and manage IDEs inside it; Neovim config → out of scope
• Project linters/formatters/LSP issues → project work, not machine setup
• EDITOR/git editor variables → zsh-setup / git-ssh-identity

Safety rails

• Never replace an existing settings.json wholesale. Read it, merge keys, back up first (cp settings.json settings.json.bak). It lives at ~/Library/Application Support/Code/User/settings.json.
• Install only extensions the user confirms — extension bloat slows startup and each one is third-party code.

Workflow

1. Install

brew install --cask visual-studio-code cursor    # default pair; zed on request

2. CLI launchers

The casks link code and cursor into brew's bin — verify both with --version in a fresh shell. If missing (e.g. .dmg install): Command Palette (⇧⌘P) → "Shell Command: Install 'code' command in PATH" (same palette command inside Cursor); Zed installs zed via its own palette command.

3. Settings baseline (merge, don't replace)

Back up first (cp settings.json settings.json.bak.$(date +%Y%m%d%H%M%S)), then merge. The first three keys rewrite source files on save — great defaults, but confirm them with the user (surprise whole-file diffs on shared repos otherwise), and exempt Markdown where trailing spaces are hard line breaks:

// merge into ~/Library/Application Support/Code/User/settings.json
{
  "editor.formatOnSave": true,              // opt-in: rewrites files on save
  "files.trimTrailingWhitespace": true,     // opt-in
  "files.insertFinalNewline": true,         // opt-in
  "[markdown]": { "files.trimTrailingWhitespace": false },
  "files.trimFinalNewlines": true,
  "editor.renderWhitespace": "boundary",
  "terminal.integrated.defaultProfile.osx": "zsh",
  "git.autofetch": true,                    // note: background network fetches
  "workbench.startupEditor": "none",
  "editor.fontFamily": "'JetBrainsMono Nerd Font', Menlo, monospace" // if Nerd Font installed (zsh-setup)
}

Don't force one global formatter for every language — set formatters per language when a project needs them.

4. Minimal extension set (confirm each)

code --install-extension editorconfig.editorconfig
code --install-extension eamodio.gitlens            # or skip; taste
code --install-extension ms-vscode-remote.remote-ssh
code --install-extension ms-azuretools.vscode-docker     # if containers are used

Language extensions: install the official one for languages the user actually works in (ask), not a prophylactic pile. Track extensions in the Brewfile via vscode "publisher.ext" entries (brew bundle dump captures them when VS Code is installed).

5. Cross-machine sync

Settings Sync: manual sign-in (GitHub/Microsoft) via the account icon — syncs settings, keybindings, extensions. Alternative: keep settings.json in the dotfiles repo (→ dotfiles-setup) — pick one mechanism, not both.

6. Cursor / Zed specifics

• Cursor (installed above): offers to import VS Code settings + extensions on first launch — do that after step 3 so the baseline carries over; settings live at ~/Library/Application Support/Cursor/ User/settings.json; extensions via cursor --install-extension; AI features need its account sign-in (manual).
• Zed (brew install --cask zed): fastest of the three, leaner extension ecosystem; zed CLI via its palette; settings are JSON at ~/.config/zed/settings.json (different keys — don't copy VS Code's).

7. Verify

code --version (fresh shell); code --list-extensions matches the confirmed set; open a scratch JSON file, add stray whitespace, save — formatting applies (JSON has a built-in formatter, so this test needs no extension).

Output spec

Done means: editor installed, CLI launcher works in a new shell, baseline merged with backup of the previous settings, confirmed extensions installed, sync mechanism chosen (or consciously skipped).

Gotchas

• Two sync mechanisms (Settings Sync + dotfiles-tracked settings.json) fight each other — silent overwrites; pick one.
• code works in the install terminal but not new ones → the palette "Install code command" writes to a path not in PATH on some setups; brew-cask installs avoid this.
• settings.json is JSON-with-comments — plain jq round-trips strip comments; edit textually when comments exist.
• Cursor and VS Code coexist fine but fight over file-type default-open associations; that's a Finder setting, not an editor bug.
• Electron editors auto-update themselves (cask auto_updates) — plain brew upgrade skips them by design (see mac-maintenance).