Add comments/docs and make method name clearer

macos/Sources/Features/Terminal/TerminalWindow.swift

@@ -34,14 +34,17 @@ class TerminalWindow: NSWindow {
     // The tab bar controller ID from macOS
     static private let TabBarController = NSUserInterfaceItemIdentifier("_tabBarController")
 
+    // Look through the titlebar's view hierarchy and hide any of the internal
+    // views used to create a separator between the title/toolbar and unselected
+    // tabs in the tab bar.
     override func updateConstraintsIfNeeded() {
         super.updateConstraintsIfNeeded()
 
         guard let titlebarContainer = contentView?.superview?.subviews.first(where: {
             $0.className == "NSTitlebarContainerView"
         }) else { return }
 
-        for v in titlebarContainer.subviews(withClassName: "NSTitlebarSeparatorView") {
+        for v in titlebarContainer.descendants(withClassName: "NSTitlebarSeparatorView") {
             v.isHidden = true
         }
     }

macos/Sources/Helpers/NSView+Extension.swift

@@ -1,16 +1,16 @@
 import AppKit
 
 extension NSView {
-
-    func subviews(withClassName name: String) -> [NSView] {
+    /// Recursively finds and returns descendant views that have the given class name.
+    func descendants(withClassName name: String) -> [NSView] {
         var result = [NSView]()
 
         for subview in subviews {
             if String(describing: type(of: subview)) == name {
                 result.append(subview)
             }
 
-            result += subview.subviews(withClassName: name)
+            result += subview.descendants(withClassName: name)
         }
 
         return result