test: textstyles test coverage

packages/app_ui/lib/app_ui.dart

@@ -4,6 +4,7 @@ library app_ui;
 import 'package:app_ui/src/generated/assets.gen.dart';
 
 export 'src/theme/vertex_theme.dart';
+export 'src/typography/vertex_text_styles.dart';
 export 'src/widgets/widgets.dart';
 
 /// Global reference to actual app_ui icons.

packages/app_ui/test/src/theme/vertex_theme_test.dart

@@ -0,0 +1,11 @@
+import 'package:app_ui/app_ui.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('VertexTheme themeData', () {
+    test('is defined for standard', () {
+      expect(VertexTheme.standard, isA<ThemeData>());
+    });
+  });
+}

packages/app_ui/test/src/typography/vertex_text_styles_test.dart

@@ -0,0 +1,13 @@
+import 'package:app_ui/app_ui.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('VertexTextStyles', () {
+    test('is defined for both display, body, and label', () {
+      expect(VertexTextStyles.display, isA<TextStyle>());
+      expect(VertexTextStyles.body, isA<TextStyle>());
+      expect(VertexTextStyles.label, isA<TextStyle>());
+    });
+  });
+}