settings test [nfc]: Pull out checkRadioButtonAppearsChecked helper

Author: chrisbobbe

test/widgets/settings_test.dart

@@ -26,11 +26,26 @@ void main() {
     await tester.pump();
   }
 
-  group('ThemeSetting', () {
-    Finder findRadioListTileWithTitle(String title) => find.ancestor(
-      of: find.text(title),
-      matching: find.byType(RadioListTile<ThemeSetting?>));
+  Finder findRadioListTileWithTitle<T>(String title) => find.ancestor(
+    of: find.text(title),
+    matching: find.byType(RadioListTile<T>));
+
+  void checkRadioButtonAppearsChecked<T>(WidgetTester tester, String title, bool expectedIsChecked) {
+    check(tester.semantics.find(findRadioListTileWithTitle<T>(title)))
+      // `.legacyMatcher()` wrapper just because flutter_checks's
+      //   `matchesSemantics` doesn't yet have a `hasSelectedState` param
+      .legacyMatcher(matchesSemantics(
+        label: title,
+        isFocusable: true,
+        hasEnabledState: true, isEnabled: true,
+        isInMutuallyExclusiveGroup: true,
+        hasCheckedState: true, isChecked: expectedIsChecked,
+        hasSelectedState: true,
+        hasTapAction: true,
+        hasFocusAction: true));
+  }
 
+  group('ThemeSetting', () {
     void checkThemeSetting(WidgetTester tester, {
       required ThemeSetting? expectedThemeSetting,
     }) {
@@ -40,19 +55,7 @@ void main() {
         ThemeSetting.dark => 'Dark',
       };
       for (final title in ['System', 'Light', 'Dark']) {
-        final expectedIsChecked = title == expectedCheckedTitle;
-        check(tester.semantics.find(findRadioListTileWithTitle(title)))
-          // `.legacyMatcher()` wrapper just because flutter_checks's
-          //   `matchesSemantics` doesn't yet have a `hasSelectedState` param
-          .legacyMatcher(matchesSemantics(
-            label: title,
-            isFocusable: true,
-            hasEnabledState: true, isEnabled: true,
-            isInMutuallyExclusiveGroup: true,
-            hasCheckedState: true, isChecked: expectedIsChecked,
-            hasSelectedState: true,
-            hasTapAction: true,
-            hasFocusAction: true));
+        checkRadioButtonAppearsChecked<ThemeSetting?>(tester, title, title == expectedCheckedTitle);
       }
       check(testBinding.globalStore)
         .settings.themeSetting.equals(expectedThemeSetting);
@@ -67,13 +70,13 @@ void main() {
       check(Theme.of(element)).brightness.equals(Brightness.light);
       checkThemeSetting(tester, expectedThemeSetting: ThemeSetting.light);
 
-      await tester.tap(findRadioListTileWithTitle('Dark'));
+      await tester.tap(findRadioListTileWithTitle<ThemeSetting?>('Dark'));
       await tester.pump();
       await tester.pump(Duration(milliseconds: 250)); // wait for transition
       check(Theme.of(element)).brightness.equals(Brightness.dark);
       checkThemeSetting(tester, expectedThemeSetting: ThemeSetting.dark);
 
-      await tester.tap(findRadioListTileWithTitle('System'));
+      await tester.tap(findRadioListTileWithTitle<ThemeSetting?>('System'));
       await tester.pump();
       await tester.pump(Duration(milliseconds: 250)); // wait for transition
       check(Theme.of(element)).brightness.equals(Brightness.light);