fix(custom-sidebar): render Menu nodes so context-menu submenus appear

Packages/macOS/CmuxSwiftRenderUI/Sources/CmuxSwiftRenderUI/Runtime/SceneNodeView.swift

@@ -155,6 +155,10 @@ private struct SceneNodeContent: View {
             }
         case "contextMenu":
             children
+        case "menu":
+            // Inside a context menu this becomes a submenu; elsewhere, a
+            // menu button.
+            Menu(node.string("text") ?? "") { children }
         case "textfield":
             SceneTextFieldView(node: node, sink: sink)
         case "reorderable":

Packages/macOS/CmuxSwiftRenderUI/Tests/CmuxSwiftRenderUITests/SceneNodeViewRenderingTests.swift

@@ -0,0 +1,62 @@
+import AppKit
+@testable import CmuxSwiftRenderUI
+import SwiftUI
+import Testing
+
+/// Opens a scene row's context menu through the real host view, the same
+/// AppKit path a right-click takes, so menu items the host fails to render
+/// show up as missing entries.
+@MainActor
+struct SceneNodeViewRenderingTests {
+    private func contextMenu(ofRoot runtime: SidebarJSRuntime) throws -> NSMenu {
+        let rootId = try #require(runtime.store.rootId)
+        let host = NSHostingView(
+            rootView: SceneNodeView(nodeId: rootId)
+                .environment(\.sceneStore, runtime.store)
+        )
+        let window = NSWindow(
+            contentRect: NSRect(x: 0, y: 0, width: 300, height: 200),
+            styleMask: [.titled],
+            backing: .buffered,
+            defer: false
+        )
+        window.contentView = host
+        host.layoutSubtreeIfNeeded()
+        let center = NSPoint(x: host.bounds.midX, y: host.bounds.midY)
+        let event = try #require(NSEvent.mouseEvent(
+            with: .rightMouseDown,
+            location: host.convert(center, to: nil),
+            modifierFlags: [],
+            timestamp: 0,
+            windowNumber: window.windowNumber,
+            context: nil,
+            eventNumber: 0,
+            clickCount: 1,
+            pressure: 1
+        ))
+        return try #require(host.menu(for: event))
+    }
+
+    /// https://github.com/manaflow-ai/cmux/issues/14662: a `Menu` inside
+    /// `.contextMenu` rendered nothing, so the submenu vanished from the
+    /// context menu while its sibling buttons still showed.
+    @Test func contextMenuSubmenuRenders() throws {
+        let runtime = SidebarJSRuntime()
+        runtime.start(source: """
+        sidebar(() =>
+          Text("row").contextMenu([
+            Button("Open chat", () => {}),
+            Divider(),
+            Menu("Move to project", [Button("fun", () => {}), Button("Landing", () => {})]),
+          ])
+        )
+        """)
+        let menu = try contextMenu(ofRoot: runtime)
+
+        #expect(menu.items.first?.title == "Open chat")
+        #expect(menu.items.contains { $0.isSeparatorItem })
+        let submenuItem = try #require(menu.items.first { $0.title == "Move to project" })
+        let submenu = try #require(submenuItem.submenu)
+        #expect(submenu.items.map(\.title) == ["fun", "Landing"])
+    }
+}

docs/custom-sidebars.md

@@ -189,7 +189,10 @@ Rules of the runtime:
 - Right-click menus: `.contextMenu([Button("Pin", fn), Divider(),
   Menu("Move", [...]), Button("Close", fn).destructive()])` on any view. Menu
   items are ordinary Button/Menu/Divider nodes, so labels and actions can be
-  live bindings (`Button(() => w().pinned ? "Unpin" : "Pin", ...)`). Useful
+  live bindings (`Button(() => w().pinned ? "Unpin" : "Pin", ...)`). The menu
+  opens only over the view it is attached to, so put it on the row's outer
+  HStack when right-clicking anywhere on the row, including the empty space a
+  Spacer fills, should open it. Useful
   verbs: `workspace.action` (pin/unpin, mark_read/mark_unread,
   move_up/move_down/move_top, close_others, set/clear color and description),
   `workspace.close`, `workspace.move_to_window`, `workspace.group.action`