feat: Add response delay generator to mock_server

lib/features/document_search/view/document_search_page.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 
 import 'package:collection/collection.dart';
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:paperless_mobile/core/navigation/push_routes.dart';
@@ -75,6 +76,17 @@ class _DocumentSearchPageState extends State<DocumentSearchPage> {
             },
           ).padded(),
         ],
+        bottom: PreferredSize(
+          preferredSize: Size.fromHeight(1),
+          child: BlocBuilder<DocumentSearchCubit, DocumentSearchState>(
+            builder: (context, state) {
+              if (state.isLoading) {
+                return const LinearProgressIndicator();
+              }
+              return const SizedBox.shrink();
+            },
+          ),
+        ),
       ),
       body: Column(
         children: [
@@ -117,24 +129,17 @@ class _DocumentSearchPageState extends State<DocumentSearchPage> {
             childCount: historyMatches.length,
           ),
         ),
-        if (state.isLoading)
-          const SliverToBoxAdapter(
-            child: Center(
-              child: CircularProgressIndicator(),
-            ),
-          )
-        else
-          SliverList(
-            delegate: SliverChildBuilderDelegate(
-              (context, index) => ListTile(
-                title: Text(suggestions[index]),
-                leading: const Icon(Icons.search),
-                onTap: () => _selectSuggestion(suggestions[index]),
-                trailing: _buildInsertSuggestionButton(suggestions[index]),
-              ),
-              childCount: suggestions.length,
+        SliverList(
+          delegate: SliverChildBuilderDelegate(
+            (context, index) => ListTile(
+              title: Text(suggestions[index]),
+              leading: const Icon(Icons.search),
+              onTap: () => _selectSuggestion(suggestions[index]),
+              trailing: _buildInsertSuggestionButton(suggestions[index]),
             ),
+            childCount: suggestions.length,
           ),
+        ),
       ],
     );
   }

lib/main.dart

@@ -75,7 +75,14 @@ Future<void> _initHive() async {
 
 void main() async {
   if (kDebugMode) {
-    await LocalMockApiServer().start();
+    // URL: http://localhost:3131
+    // Login: admin:test
+    await LocalMockApiServer(
+      RandomDelayGenerator(
+        const Duration(milliseconds: 100),
+        const Duration(milliseconds: 800),
+      ),
+    ).start();
   }
   await _initHive();
   final widgetsBinding = WidgetsFlutterBinding.ensureInitialized();

packages/mock_server/lib/mock_server.dart

@@ -1,10 +1,13 @@
 library mock_server;
 
+export 'response_delay_generator.dart';
+
 import 'dart:convert';
 import 'dart:math';
 import 'package:http/http.dart' as http;
 
 import 'package:logging/logging.dart';
+import 'package:mock_server/response_delay_generator.dart';
 
 import 'package:shelf/shelf.dart';
 
@@ -23,27 +26,29 @@ class LocalMockApiServer {
 
   static get baseUrl => 'http://$host:$port/';
 
+  final DelayGenerator _delayGenerator;
+
   late shelf_router.Router app;
   Future<Map<String, dynamic>> loadFixture(String name) async {
     var fixture = await rootBundle.loadString('packages/mock_server/fixtures/$name.json');
     return json.decode(fixture);
   }
 
-  LocalMockApiServer() {
+  LocalMockApiServer([this._delayGenerator = const ZeroDelayGenerator()]) {
     app = shelf_router.Router();
 
     Map<String, dynamic> createdTags = {};
 
     app.get('/api/', (Request req) async {
       log.info('Responding to /api');
-      return JsonMockResponse.ok({});
+      return JsonMockResponse.ok({}, _delayGenerator.nextDelay());
     });
 
     app.post('/api/token/', (Request req) async {
       log.info('Responding to /api/token/');
       var body = await req.bodyJsonMap();
       if (body?['username'] == 'admin' && body?['password'] == 'test') {
-        return JsonMockResponse.ok({'token': 'testToken'});
+        return JsonMockResponse.ok({'token': 'testToken'}, _delayGenerator.nextDelay());
       } else {
         return Response.unauthorized('Unauthorized');
       }
@@ -52,37 +57,37 @@ class LocalMockApiServer {
     app.get('/api/ui_settings/', (Request req) async {
       log.info('Responding to /api/ui_settings/');
       var data = await loadFixture('ui_settings');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/users/<userId>/', (Request req, String userId) async {
       log.info('Responding to /api/users/<userId>/');
       var data = await loadFixture('user-1');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/users/', (Request req, String userId) async {
       log.info('Responding to /api/users/');
       var data = await loadFixture('users');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/groups/', (Request req, String userId) async {
       log.info('Responding to /api/groups/');
       var data = await loadFixture('groups');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/correspondents/', (Request req) async {
       log.info('Responding to /api/correspondents/');
       var data = await loadFixture('correspondents');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/document_types/', (Request req) async {
       log.info('Responding to /api/document_types/');
       var data = await loadFixture('doc_types');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/tags/', (Request req) async {
@@ -91,7 +96,7 @@ class LocalMockApiServer {
         var data = await loadFixture("tags");
         createdTags = data;
       }
-      return JsonMockResponse.ok(createdTags);
+      return JsonMockResponse.ok(createdTags, _delayGenerator.nextDelay());
     });
 
     app.post('/api/tags/', (Request req) async {
@@ -156,25 +161,25 @@ class LocalMockApiServer {
     app.get('/api/storage_paths/', (Request req) async {
       log.info('Responding to /api/storage_paths/');
       var data = await loadFixture('storage_paths');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/storage_paths/', (Request req) async {
       log.info('Responding to /api/storage_paths/');
       var data = await loadFixture('storage_paths');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/saved_views/', (Request req) async {
       log.info('Responding to /api/saved_views/');
       var data = await loadFixture('saved_views');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/documents/', (Request req) async {
       log.info('Responding to /api/documents/');
       var data = await loadFixture('documents');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/documents/<docId>/thumb/', (Request req, String docId) async {
@@ -194,39 +199,39 @@ class LocalMockApiServer {
     app.get('/api/documents/<docId>/metadata/', (Request req, String docId) async {
       log.info('Responding to /api/documents/<docId>/metadata/');
       var data = await loadFixture('metadata');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     //This is not yet used in the app
     app.get('/api/documents/<docId>/suggestions/', (Request req, String docId) async {
       log.info('Responding to /api/documents/<docId>/suggestions/');
       var data = await loadFixture('suggestions');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     //This is not yet used in the app
     app.get('/api/documents/<docId>/notes/', (Request req, String docId) async {
       log.info('Responding to /api/documents/<docId>/notes/');
       var data = await loadFixture('notes');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/tasks/', (Request req) async {
       log.info('Responding to /api/tasks/');
       var data = await loadFixture('tasks');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/statistics/', (Request req) async {
       log.info('Responding to /api/statistics/');
       var data = await loadFixture('statistics');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
 
     app.get('/api/statistics/', (Request req) async {
       log.info('Responding to /api/statistics/');
       var data = await loadFixture('statistics');
-      return JsonMockResponse.ok(data);
+      return JsonMockResponse.ok(data, _delayGenerator.nextDelay());
     });
   }
 
@@ -264,8 +269,8 @@ extension on Request {
 }
 
 extension JsonMockResponse on Response {
-  static ok<T>(T json, {int delay = 800}) async {
-    await Future.delayed(Duration(milliseconds: delay)); // Emulate lag
+  static ok<T>(T json, Duration delay) async {
+    await Future.delayed(delay); // Emulate lag
 
     return Response.ok(
       jsonEncode(json),

packages/mock_server/lib/response_delay_generator.dart

@@ -0,0 +1,46 @@
+import 'dart:math';
+
+abstract interface class DelayGenerator {
+  Duration nextDelay();
+}
+
+class RandomDelayGenerator implements DelayGenerator {
+  /// Minimum allowed response delay
+  final Duration minDelay;
+
+  /// Maximum allowed response delay
+  final Duration maxDelay;
+
+  final Random _random = Random();
+  RandomDelayGenerator(this.minDelay, this.maxDelay);
+
+  @override
+  Duration nextDelay() {
+    return Duration(
+      milliseconds: minDelay.inMilliseconds +
+          _random.nextInt(
+            maxDelay.inMilliseconds - minDelay.inMilliseconds,
+          ),
+    );
+  }
+}
+
+class ConstantDelayGenerator implements DelayGenerator {
+  final Duration delay;
+
+  const ConstantDelayGenerator(this.delay);
+
+  @override
+  Duration nextDelay() {
+    return delay;
+  }
+}
+
+class ZeroDelayGenerator implements DelayGenerator {
+  const ZeroDelayGenerator();
+
+  @override
+  Duration nextDelay() {
+    return Duration.zero;
+  }
+}