halkyon_app: data locations as precise as a country or a state

An operator's DATA_LOCATION and BACKUP_LOCATION may name a subdivision
(ISO 3166-2, US-CA, DE-BY) besides the EU or a country. The app adds
"(EU)" to a member country and the country to a subdivision ("Germany
(EU)", "California, United States", "Bavaria, Germany (EU)"), in
English and German, and shows the most specific flag there is: a
subdivision's own where the flag package has one, else its country's.
Subdivision names come from Unicode CLDR 48.2 (tool/subdivision_names.py),
bundled with their licence, which the app registers.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

packages/halkyon_app/test/instance/widget/instance_flag_test.dart

@@ -0,0 +1,37 @@
+import 'package:flag/flag.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/halkyon_app.dart';
+import 'package:material_ui/material_ui.dart';
+
+void main() {
+  test("a place shows the most specific flag there is: a subdivision's own, "
+      "else its country's, and the European Union's", () {
+    expect(flagCodeOf('EU'), 'eu');
+    expect(flagCodeOf('DE'), 'de');
+    expect(flagCodeOf('CH'), 'ch');
+    expect(flagCodeOf('DE-BY'), 'de');
+    expect(flagCodeOf('US-CA'), 'us');
+    expect(flagCodeOf('GB-SCT'), 'gb_sct');
+    expect(flagCodeOf('ES-CT'), 'es_ct');
+    expect(flagCodeOf('DE-ZZ'), 'de');
+  });
+
+  test('a place without a flag shows none', () {
+    expect(flagCodeOf('QQ'), isNull);
+    expect(flagCodeOf('QQ-AB'), isNull);
+  });
+
+  testWidgets("a state shows its country's flag, a place without one "
+      'nothing', (tester) async {
+    await tester.pumpWidget(
+      const Directionality(
+        textDirection: TextDirection.ltr,
+        child: Row(
+          children: [InstanceFlag('US-CA'), InstanceFlag('QQ-AB')],
+        ),
+      ),
+    );
+
+    expect(find.byType(Flag), findsOne);
+  });
+}

packages/halkyon_app/test/instance/widget/instance_location_words_test.dart

@@ -6,7 +6,15 @@ import 'package:halkyon_app/l10n/halkyon_app_localizations_en.dart';
 void main() {
   final en = HalkyonAppLocalizationsEn();
   final de = HalkyonAppLocalizationsDe();
-  const names = {'CH': 'Switzerland', 'DE': 'Germany'};
+  const names = {
+    'CH': 'Switzerland',
+    'DE': 'Germany',
+    'GB': 'United Kingdom',
+    'US': 'United States',
+    'DE-BY': 'Bavaria',
+    'GB-SCT': 'Scotland',
+    'US-CA': 'California',
+  };
   String? words(InstanceLocations locations) =>
       instanceLocationWords(en, locations, names);
 
@@ -15,6 +23,10 @@ void main() {
       words(const InstanceLocations(data: 'EU', backups: 'EU')),
       'Data and backups: European Union',
     );
+    expect(
+      words(const InstanceLocations(data: 'DE-BY', backups: 'DE-BY')),
+      'Data and backups: Bavaria, Germany (EU)',
+    );
   });
 
   test('data and backups apart are named a line each', () {
@@ -24,6 +36,28 @@ void main() {
     );
   });
 
+  test('a member of the European Union says so after its name; another '
+      'country is named alone', () {
+    expect(words(const InstanceLocations(data: 'DE')), 'Data: Germany (EU)');
+    expect(words(const InstanceLocations(data: 'CH')), 'Data: Switzerland');
+  });
+
+  test('a subdivision is named with its country, a member of the European '
+      'Union saying so', () {
+    expect(
+      words(const InstanceLocations(data: 'DE-BY')),
+      'Data: Bavaria, Germany (EU)',
+    );
+    expect(
+      words(const InstanceLocations(data: 'US-CA')),
+      'Data: California, United States',
+    );
+    expect(
+      words(const InstanceLocations(data: 'GB-SCT')),
+      'Data: Scotland, United Kingdom',
+    );
+  });
+
   test('an instance keeping no backups says so', () {
     expect(
       words(
@@ -37,7 +71,6 @@ void main() {
   });
 
   test('what the instance leaves unsaid is left out', () {
-    expect(words(const InstanceLocations(data: 'DE')), 'Data: Germany');
     expect(
       words(const InstanceLocations(backups: 'CH')),
       'Backups: Switzerland',
@@ -45,8 +78,12 @@ void main() {
     expect(words(const InstanceLocations()), isNull);
   });
 
-  test('a country without a name here goes by its code', () {
+  test('a country or subdivision without a name here goes by its code', () {
     expect(words(const InstanceLocations(data: 'XK')), 'Data: XK');
+    expect(
+      words(const InstanceLocations(data: 'DE-ZZ')),
+      'Data: DE-ZZ, Germany (EU)',
+    );
   });
 
   test('in German too, without the articles some countries take', () {
@@ -58,5 +95,21 @@ void main() {
       ),
       'Daten: Europäische Union\nSicherungen: Schweiz',
     );
+    expect(
+      instanceLocationWords(
+        de,
+        const InstanceLocations(data: 'DE-BY', backups: 'FI'),
+        const {'DE': 'Deutschland', 'DE-BY': 'Bayern', 'FI': 'Finnland'},
+      ),
+      'Daten: Bayern, Deutschland (EU)\nSicherungen: Finnland (EU)',
+    );
+    expect(
+      instanceLocationWords(
+        de,
+        const InstanceLocations(data: 'US-CA', backups: 'US-CA'),
+        const {'US': 'Vereinigte Staaten', 'US-CA': 'Kalifornien'},
+      ),
+      'Daten und Sicherungen: Kalifornien, Vereinigte Staaten',
+    );
   });
 }