feat: Automatically cache storable files on upload

lib/src/client.dart

@@ -19,6 +19,7 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:core';
+import 'dart:typed_data';
 
 import 'package:http/http.dart' as http;
 
@@ -520,6 +521,20 @@ class Client extends MatrixApi {
     return archiveList;
   }
 
+  /// Uploads a file and automatically caches it in the database, if it is small enough
+  /// and returns the mxc url as a string.
+  @override
+  Future<String> upload(Uint8List file, String fileName,
+      {String contentType}) async {
+    final mxc = await super.upload(file, fileName, contentType: contentType);
+    final storeable = database != null && file.length <= database.maxFileSize;
+    if (storeable) {
+      await database.storeFile(
+          mxc, file, DateTime.now().millisecondsSinceEpoch);
+    }
+    return mxc;
+  }
+
   /// Uploads a new user avatar for this user.
   Future<void> setAvatar(MatrixFile file) async {
     final uploadResp = await upload(file.bytes, file.name);

test/client_test.dart

@@ -31,6 +31,7 @@ import 'package:test/test.dart';
 
 import 'fake_matrix_api.dart';
 import 'fake_database.dart';
+import 'fake_client.dart';
 
 void main() {
   Client matrix;
@@ -444,6 +445,13 @@ void main() {
       await matrix.ignoreUser('@charley2:stupid.abc');
       await matrix.unignoreUser('@charley:stupid.abc');
     });
+    test('upload', () async {
+      final client = await getClient();
+      final response = await client.upload(Uint8List(0), 'file.jpeg');
+      expect(response, 'mxc://example.com/AQwafuaFswefuhsfAFAgsw');
+      expect(await client.database.getFile(response) != null, true);
+      await client.dispose(closeDatabase: true);
+    });
 
     test('dispose', () async {
       await matrix.dispose(closeDatabase: true);