add auto-upgrade settings, split into formulae and casks

Two independent toggles, both off by default. When a scheduled fetch
finds outdated packages, runAutoUpgrade runs "upgrade --formula" and/or
"upgrade --cask" (with --greedy if that setting is on), then refetches.

The refetch passes allowAutoUpgrade: false — packages can legitimately
stay outdated after an upgrade (pinned formulae, greedy casks brew
declines), and without the guard that would trigger upgrade → fetch →
upgrade forever. Manual Upgrade All's final fetch gets the same guard.

The casks checkbox carries a warning note in the settings window: a
cask upgrade can close and replace the running app without warning.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

BrewBar/BrewBarApp.swift

@@ -213,7 +213,8 @@ class AppDelegate: NSObject, NSApplicationDelegate {
 
         runBrew("update") { _ in
             self.runBrew("upgrade") { _ in
-                self.fetchOutdated()
+                // everything was just upgraded; don't chain an auto-upgrade
+                self.fetchOutdated(allowAutoUpgrade: false)
             }
         }
     }
@@ -242,7 +243,10 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         return alert.runModal() == .alertFirstButtonReturn
     }
 
-    func fetchOutdated() {
+    /// allowAutoUpgrade guards against an upgrade loop: packages can stay
+    /// outdated after an upgrade (pinned formulae, greedy casks brew declines),
+    /// so the fetch that follows an auto-upgrade must not trigger another one.
+    func fetchOutdated(allowAutoUpgrade: Bool = true) {
         setMenuBarIcon("brewbar-updating")
 
         // --greedy also lists casks that self-update (brew skips them by default)
@@ -253,6 +257,13 @@ class AppDelegate: NSObject, NSApplicationDelegate {
 
             self.cachedOutdated = lines
 
+            if allowAutoUpgrade, !lines.isEmpty,
+               Settings.autoUpgradeFormulae || Settings.autoUpgradeCasks
+            {
+                self.runAutoUpgrade()
+                return
+            }
+
             self.updateOutdatedMenu(with: lines)
             self.updateStatus(count: lines.count)
             if lines.isEmpty {
@@ -263,6 +274,29 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         }
     }
 
+    func runAutoUpgrade() {
+        statusMenuItem.title = "Auto-upgrading..."
+
+        let upgradeCasksThenRefresh = {
+            if Settings.autoUpgradeCasks {
+                let command = Settings.includeGreedyCasks ? "upgrade --cask --greedy" : "upgrade --cask"
+                self.runBrew(command) { _ in
+                    self.fetchOutdated(allowAutoUpgrade: false)
+                }
+            } else {
+                self.fetchOutdated(allowAutoUpgrade: false)
+            }
+        }
+
+        if Settings.autoUpgradeFormulae {
+            runBrew("upgrade --formula") { _ in
+                upgradeCasksThenRefresh()
+            }
+        } else {
+            upgradeCasksThenRefresh()
+        }
+    }
+
     func updateOutdatedMenu(with lines: [String]) {
         outdatedSubmenu.removeAllItems()
         outdatedItem.isHidden = lines.isEmpty

BrewBar/SettingsWindowController.swift

@@ -16,6 +16,8 @@ class SettingsWindowController: NSWindowController {
     var customMinutesField: NSTextField!
     var launchAtLoginCheckbox: NSButton!
     var greedyCheckbox: NSButton!
+    var autoUpgradeFormulaeCheckbox: NSButton!
+    var autoUpgradeCasksCheckbox: NSButton!
 
     convenience init(appDelegate: AppDelegate) {
         let window = NSWindow(
@@ -81,11 +83,40 @@ class SettingsWindowController: NSWindowController {
             action: #selector(toggleGreedy(_:))
         )
 
+        autoUpgradeFormulaeCheckbox = NSButton(
+            checkboxWithTitle: "Automatically upgrade formulae (command-line tools)",
+            target: self,
+            action: #selector(toggleAutoUpgradeFormulae(_:))
+        )
+
+        autoUpgradeCasksCheckbox = NSButton(
+            checkboxWithTitle: "Automatically upgrade casks (apps)",
+            target: self,
+            action: #selector(toggleAutoUpgradeCasks(_:))
+        )
+
+        let caskWarning = NSTextField(
+            wrappingLabelWithString: "⚠️ Upgrading a cask can close and replace the app while it is running (e.g. your browser), without warning."
+        )
+        caskWarning.font = .systemFont(ofSize: NSFont.smallSystemFontSize)
+        caskWarning.textColor = .secondaryLabelColor
+        caskWarning.preferredMaxLayoutWidth = 320
+
+        // indent the note so it reads as belonging to the checkbox above
+        let spacer = NSView()
+        spacer.widthAnchor.constraint(equalToConstant: 18).isActive = true
+        let caskWarningRow = NSStackView(views: [spacer, caskWarning])
+        caskWarningRow.orientation = .horizontal
+
         let stack = NSStackView(views: [
             frequencyRow,
             customRow,
             greedyCheckbox,
             separator(),
+            autoUpgradeFormulaeCheckbox,
+            autoUpgradeCasksCheckbox,
+            caskWarningRow,
+            separator(),
             launchAtLoginCheckbox,
         ])
         stack.orientation = .vertical
@@ -122,6 +153,8 @@ class SettingsWindowController: NSWindowController {
         // this in System Settings > Login Items while we weren't looking
         launchAtLoginCheckbox.state = SMAppService.mainApp.status == .enabled ? .on : .off
         greedyCheckbox.state = Settings.includeGreedyCasks ? .on : .off
+        autoUpgradeFormulaeCheckbox.state = Settings.autoUpgradeFormulae ? .on : .off
+        autoUpgradeCasksCheckbox.state = Settings.autoUpgradeCasks ? .on : .off
     }
 
     func separator() -> NSBox {
@@ -159,6 +192,14 @@ class SettingsWindowController: NSWindowController {
         appDelegate?.fetchOutdated() // the list contents just changed meaning
     }
 
+    @objc func toggleAutoUpgradeFormulae(_ sender: NSButton) {
+        Settings.autoUpgradeFormulae = sender.state == .on
+    }
+
+    @objc func toggleAutoUpgradeCasks(_ sender: NSButton) {
+        Settings.autoUpgradeCasks = sender.state == .on
+    }
+
     @objc func toggleLaunchAtLogin(_ sender: NSButton) {
         do {
             if sender.state == .on {