nextcloud: Add some more core tests

packages/nextcloud/test/core.dart

@@ -1,3 +1,4 @@
+import 'package:crypto/crypto.dart';
 import 'package:nextcloud/nextcloud.dart';
 import 'package:test/test.dart';
 
@@ -98,5 +99,33 @@ Future run(final DockerImage image) async {
       expect(response.ocs.data[2].subline, '');
       expect(response.ocs.data[2].shareWithDisplayNameUnique, '');
     });
+
+    test('Get preview', () async {
+      final response = await client.core.getPreview(file: 'Nextcloud.png');
+      expect(sha1.convert(response).toString(), '168c31b76ae4e8bdc5f8edd4c896f40e9d4afe1e');
+    });
+
+    test('Get avatar', () async {
+      final response = await client.core.getAvatar(userId: 'admin', size: 32);
+      expect(sha1.convert(response).toString(), '618830d6512203281de64cc738e8a7b0cc3d1f47');
+    });
+
+    test('Get dark avatar', () async {
+      final response = await client.core.getDarkAvatar(userId: 'admin', size: 32);
+      expect(sha1.convert(response).toString(), 'e7294d71b817d05940574061008c80a7d7a04b87');
+    });
+
+    test('Delete app password', () async {
+      client = await getTestClient(
+        container,
+        useAppPassword: true,
+      );
+
+      await client.core.deleteAppPassword();
+      expect(
+        () => client.core.getCapabilities(),
+        throwsA(predicate((final e) => (e! as NextcloudApiException).statusCode == 401)),
+      );
+    });
   });
 }