fix(webui): correct combobox navigation semantics

webui/src/components/settings/SettingsView.tsx

@@ -8955,14 +8955,14 @@ function TimezonePicker({
             />
           </div>
         </div>
-        <div
-          {...navigation.listProps}
-          aria-label={tx("settings.timezone.select", "Select timezone")}
-          className="mt-1 max-h-[18rem] overflow-y-auto pr-0.5 scrollbar-thin scrollbar-track-transparent"
-          data-testid="timezone-picker-list"
-        >
-          {filteredOptions.length ? (
-            filteredOptions.map((option) => {
+        {filteredOptions.length ? (
+          <div
+            {...navigation.listProps}
+            aria-label={tx("settings.timezone.select", "Select timezone")}
+            className="mt-1 max-h-[18rem] overflow-y-auto pr-0.5 scrollbar-thin scrollbar-track-transparent"
+            data-testid="timezone-picker-list"
+          >
+            {filteredOptions.map((option) => {
               const selected = option.name === value;
               return (
                 <ComboboxOption
@@ -8982,13 +8982,17 @@ function TimezonePicker({
                   </span>
                 </ComboboxOption>
               );
-            })
-          ) : (
-            <div className="px-3 py-5 text-center text-[12px] text-muted-foreground">
-              {tx("settings.timezone.empty", "No matching timezones.")}
-            </div>
-          )}
-        </div>
+            })}
+          </div>
+        ) : (
+          <div
+            role="status"
+            className="px-3 py-5 text-center text-[12px] text-muted-foreground"
+            data-testid="timezone-picker-list"
+          >
+            {tx("settings.timezone.empty", "No matching timezones.")}
+          </div>
+        )}
       </PopoverContent>
     </Popover>
   );

webui/src/components/ui/combobox.tsx

@@ -25,7 +25,10 @@ export function useComboboxNavigation({
   const [activeValue, setActiveValue] = React.useState<string | null>(null);
 
   React.useEffect(() => {
-    if (!open) return;
+    if (!open) {
+      setActiveValue(null);
+      return;
+    }
     setActiveValue((current) => {
       if (current && values.includes(current)) return current;
       if (selectedValue && values.includes(selectedValue)) return selectedValue;
@@ -54,23 +57,15 @@ export function useComboboxNavigation({
     if (event.nativeEvent.isComposing) return;
     switch (event.key) {
       case "ArrowDown":
-        event.preventDefault();
-        move(1);
-        break;
-      case "ArrowUp":
-        event.preventDefault();
-        move(-1);
-        break;
-      case "Home":
         if (values.length) {
           event.preventDefault();
-          setActiveValue(values[0]);
+          move(1);
         }
         break;
-      case "End":
+      case "ArrowUp":
         if (values.length) {
           event.preventDefault();
-          setActiveValue(values[values.length - 1]);
+          move(-1);
         }
         break;
       case "Enter":
@@ -86,12 +81,13 @@ export function useComboboxNavigation({
     }
   };
 
+  const expanded = open && values.length > 0;
   const inputProps = {
     role: "combobox" as const,
     "aria-autocomplete": "list" as const,
-    "aria-controls": listboxId,
-    "aria-expanded": open,
-    "aria-activedescendant": activeOptionId,
+    "aria-controls": expanded ? listboxId : undefined,
+    "aria-expanded": expanded,
+    "aria-activedescendant": expanded ? activeOptionId : undefined,
     onKeyDown: onInputKeyDown,
   };
 
@@ -105,7 +101,7 @@ export function useComboboxNavigation({
     return {
       id: `${listboxId}-option-${index}`,
       role: "option" as const,
-      "aria-selected": value === selectedValue,
+      "aria-selected": value === activeValue,
       "data-highlighted": value === activeValue ? "" : undefined,
       tabIndex: -1,
       onPointerMove: () => setActiveValue(value),
@@ -126,7 +122,7 @@ const ComboboxOption = React.forwardRef<
     className={cn(
       floatingItemClassName,
       floatingItemFocusClassName,
-      "w-full cursor-default text-left data-[highlighted]:bg-muted/85 data-[highlighted]:text-foreground aria-selected:bg-muted/80",
+      "w-full cursor-default text-left data-[highlighted]:bg-muted/85 data-[highlighted]:text-foreground",
       className,
     )}
     {...props}

webui/src/tests/combobox.test.tsx

@@ -1,4 +1,4 @@
-import { fireEvent, render, screen } from "@testing-library/react";
+import { createEvent, fireEvent, render, screen } from "@testing-library/react";
 import { useState } from "react";
 import { describe, expect, it } from "vitest";
 
@@ -9,12 +9,12 @@ import {
 
 const OPTIONS = ["Alpha", "Beta", "Gamma"];
 
-function ComboboxHarness() {
+function ComboboxHarness({ options = OPTIONS }: { options?: readonly string[] }) {
   const [open, setOpen] = useState(true);
   const [selected, setSelected] = useState("Beta");
   const navigation = useComboboxNavigation({
     open,
-    values: OPTIONS,
+    values: options,
     selectedValue: selected,
     onSelect: setSelected,
     onClose: () => setOpen(false),
@@ -23,9 +23,12 @@ function ComboboxHarness() {
   return (
     <>
       <input aria-label="Options" {...navigation.inputProps} />
-      {open ? (
+      <button type="button" onClick={() => setOpen((current) => !current)}>
+        {open ? "Close options" : "Open options"}
+      </button>
+      {open && options.length ? (
         <div {...navigation.listProps} aria-label="Available options">
-          {OPTIONS.map((option) => (
+          {options.map((option) => (
             <ComboboxOption key={option} {...navigation.getOptionProps(option)}>
               {option}
             </ComboboxOption>
@@ -49,6 +52,14 @@ describe("combobox navigation", () => {
     );
 
     fireEvent.keyDown(input, { key: "ArrowDown" });
+    expect(screen.getByRole("option", { name: "Beta" })).toHaveAttribute(
+      "aria-selected",
+      "false",
+    );
+    expect(screen.getByRole("option", { name: "Gamma" })).toHaveAttribute(
+      "aria-selected",
+      "true",
+    );
     expect(input).toHaveAttribute(
       "aria-activedescendant",
       screen.getByRole("option", { name: "Gamma" }).id,
@@ -58,6 +69,44 @@ describe("combobox navigation", () => {
     expect(screen.getByRole("status", { name: "Selection" })).toHaveTextContent("Gamma");
   });
 
+  it("preserves native text editing keys", () => {
+    render(<ComboboxHarness />);
+
+    const input = screen.getByRole("combobox", { name: "Options" });
+    for (const key of ["Home", "End"]) {
+      const event = createEvent.keyDown(input, { key });
+      fireEvent(input, event);
+      expect(event.defaultPrevented).toBe(false);
+    }
+  });
+
+  it("restores the selected option after closing without a selection", () => {
+    render(<ComboboxHarness />);
+
+    const input = screen.getByRole("combobox", { name: "Options" });
+    fireEvent.keyDown(input, { key: "ArrowDown" });
+    fireEvent.keyDown(input, { key: "Escape" });
+    fireEvent.click(screen.getByRole("button", { name: "Open options" }));
+
+    const selectedOption = screen.getByRole("option", { name: "Beta" });
+    expect(input).toHaveAttribute("aria-activedescendant", selectedOption.id);
+    fireEvent.keyDown(input, { key: "Enter" });
+    expect(screen.getByRole("status", { name: "Selection" })).toHaveTextContent("Beta");
+  });
+
+  it("collapses the combobox when no options are available", () => {
+    render(<ComboboxHarness options={[]} />);
+
+    const input = screen.getByRole("combobox", { name: "Options" });
+    expect(input).toHaveAttribute("aria-expanded", "false");
+    expect(input).not.toHaveAttribute("aria-controls");
+    expect(input).not.toHaveAttribute("aria-activedescendant");
+
+    const event = createEvent.keyDown(input, { key: "ArrowDown" });
+    fireEvent(input, event);
+    expect(event.defaultPrevented).toBe(false);
+  });
+
   it("closes the listbox on Escape", () => {
     render(<ComboboxHarness />);