Commit f4a55f8

@@ -3,24 +3,30 @@ import 'package:flutter/material.dart';
 /// Selects the correct language name for a specific language code.
 ///
 /// Does not account for dialects.
-String? getDisplayLanguage(Locale l) => switch(l.toLanguageTag()) {
+String getDisplayLanguage(Locale l) => switch(l.toLanguageTag()) {
   'en' => 'English',
   'en-US' => 'English (US)',
   'de' => 'Deutsch',
-  'fr' => 'française',
+  'fr' => 'Française',
   'it' => 'Italiano',
   'nb' => 'Norsk bokmål',
   'pt' => 'Português',
-  'pt-BR' => 'português (Brasil)',
-  'ru' => 'русский',
+  'pt-BR' => 'Português (Brasil)',
+  'ru' => 'Русский',
   'tr' => 'Türkçe',
   'zh' => '中文 (简体)',
   'zh-Hant' => '中文（繁體)',
   // Websites with names for expanding when new languages get added:
   // - https://chronoplexsoftware.com/localisation/help/languagecodes.htm
   // - https://localizely.com/locale-code/zh-Hans/
+  //
+  // Names should be modified so they start with an upper case letter.
+  //
   (_) => (){
-    assert(false, l.toString());
+    debugPrint('Unlocalized language tag: $l');
+    debugPrintStack();
+    assert(false, 'Should only be called for localized strings and all '
+        'localized strings are tested.');
     return l.languageCode;
   }()
 };

@@ -0,0 +1,41 @@
+import 'package:blood_pressure_app/model/iso_lang_names.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('getDisplayLanguage', () {
+    test('should have unique names for all languages provided in localizations', () {
+      final allNames = <String>[];
+      for (final locale in AppLocalizations.supportedLocales) {
+        final name = getDisplayLanguage(locale);
+        expect(allNames, isNot(contains(name)));
+        allNames.add(name);
+      }
+    });
+    test('should start all names in upper case', () {
+      for (final locale in AppLocalizations.supportedLocales) {
+        final firstChar = getDisplayLanguage(locale)[0];
+        expect(firstChar, equals(firstChar.toUpperCase()));
+      }
+    });
+    test('should not store names where no localization present', () {
+      final tmp = debugPrint;
+      int printCounts = 0;
+      debugPrint = (String? s, {int? wrapWidth}) {
+        printCounts += 1;
+      };
+      for (final c1 in 'abcdefghijklmnopqrstuvwxyz'.characters) {
+        for (final c2 in 'abcdefghijklmnopqrstuvwxyz'.characters) {
+          if (AppLocalizations.supportedLocales.where(
+              (e) => e.toLanguageTag() == '$c1$c2',).isNotEmpty) continue;
+          expect(() => getDisplayLanguage(Locale('$c1$c2')),
+              throwsAssertionError,);
+          expect(printCounts, greaterThan(1));
+          printCounts = 0;
+        }
+      }
+      debugPrint = tmp;
+    });
+  });
+}