Settings: its rows in five groups

Settings had grown to 21 rows in one list. It opens on five groups (This
device, Display, GNSS and radio, Network, System); Enter opens one, Back
returns to the groups, and Back from the groups leaves Settings.

SettingsMenu holds the groups and which one is open (host-tested: every
setting is in exactly one group). The guide, the how-tos, the README,
the scripts' messages and the firmware's own name the new paths, such as
"Settings > System > Firmware".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0162FokPdvY2KsS4NBfwyWPk

test/test_settings_menu/test_settings_menu.cpp

@@ -12,10 +12,10 @@ struct Fixture {
     Settings settings{store, bus};
     SettingsMenu menu{settings};
     Fixture() { settings.load(); }
+    // Opens the group the row is in: the index is into that group.
     int row(SettingsMenu::Row r) {
-        for (int i = 0; i < menu.count(); i++)
-            if (menu.row(i) == r) return i;
-        return -1;
+        int i = -1;
+        return menu.reveal(r, i) ? i : -1;
     }
 };
 
@@ -28,6 +28,53 @@ void test_every_row_has_a_label() {
     for (int i = 0; i < f.menu.count(); i++) TEST_ASSERT_FALSE(f.menu.label(i).empty());
 }
 
+void test_the_groups_are_listed_first() {
+    Fixture f;
+    TEST_ASSERT_FALSE(f.menu.inGroup());
+    TEST_ASSERT_EQUAL(5, f.menu.count());
+    for (int i = 0; i < f.menu.count(); i++)
+        TEST_ASSERT_EQUAL(static_cast<int>(SettingsMenu::Kind::Group), static_cast<int>(f.menu.kind(i)));
+    TEST_ASSERT_EQUAL_STRING("This device", f.menu.label(0).c_str());
+    TEST_ASSERT_EQUAL_STRING("Display", f.menu.label(1).c_str());
+    TEST_ASSERT_FALSE(f.menu.close());  // nothing to close: Back leaves Settings
+}
+
+void test_a_group_opens_and_closes() {
+    Fixture f;
+    TEST_ASSERT_TRUE(f.menu.open(1));
+    TEST_ASSERT_TRUE(f.menu.inGroup());
+    TEST_ASSERT_EQUAL_STRING("Display", f.menu.title().c_str());
+    TEST_ASSERT_EQUAL(6, f.menu.count());
+    TEST_ASSERT_EQUAL_STRING("Brightness", f.menu.label(0).c_str());
+    TEST_ASSERT_EQUAL_STRING("Launcher", f.menu.label(5).c_str());
+    TEST_ASSERT_FALSE(f.menu.open(0));  // a row of a group isn't a group
+    TEST_ASSERT_TRUE(f.menu.close());
+    TEST_ASSERT_EQUAL(1, f.menu.groupIndex());  // where the selection goes back to
+    TEST_ASSERT_EQUAL(5, f.menu.count());
+    TEST_ASSERT_FALSE(f.menu.open(5));
+}
+
+void test_every_setting_is_in_one_group() {
+    Fixture f;
+    int total = 0;
+    for (int g = 0; g < 5; g++) {
+        TEST_ASSERT_TRUE(f.menu.open(g));
+        TEST_ASSERT_TRUE(f.menu.count() > 0 && f.menu.count() <= 8);  // a title and 8 rows fit the screen
+        for (int i = 0; i < f.menu.count(); i++) {
+            TEST_ASSERT_FALSE(f.menu.label(i).empty());
+            TEST_ASSERT_NOT_EQUAL(static_cast<int>(SettingsMenu::Kind::Group), static_cast<int>(f.menu.kind(i)));
+        }
+        total += f.menu.count();
+        f.menu.close();
+    }
+    TEST_ASSERT_EQUAL(21, total);
+    int i = -1;
+    TEST_ASSERT_TRUE(f.menu.reveal(SettingsMenu::Row::Vpn, i));
+    TEST_ASSERT_EQUAL_STRING("Network", f.menu.title().c_str());
+    TEST_ASSERT_EQUAL_STRING("VPN", f.menu.label(i).c_str());
+    TEST_ASSERT_FALSE(f.menu.reveal(SettingsMenu::Row::GroupDisplay, i));
+}
+
 void test_values_are_human_readable() {
     Fixture f;
     TEST_ASSERT_EQUAL_STRING("60%", f.menu.value(f.row(SettingsMenu::Row::Brightness)).c_str());
@@ -183,6 +230,9 @@ void test_gnss_and_coordinate_rows_toggle() {
 int main() {
     UNITY_BEGIN();
     RUN_TEST(test_every_row_has_a_label);
+    RUN_TEST(test_the_groups_are_listed_first);
+    RUN_TEST(test_a_group_opens_and_closes);
+    RUN_TEST(test_every_setting_is_in_one_group);
     RUN_TEST(test_values_are_human_readable);
     RUN_TEST(test_toggle_rows_flip_on_select);
     RUN_TEST(test_the_launcher_is_a_grid_or_a_list);