refactor(app,learn): people's files on the device shared in halkyon_app

ADR 0043's recommendation, for Todo's attachments: what Learn had for its
files on the device moves into halkyon_app, unchanged but for its names,
and Learn uses it from there.

- FileCache, DirectoryFileCache (Learn's AssetFileCache): the files by
  their SHA-256 in a folder of the person's, and which wait to be
  uploaded.
- FileServerGateway, ServerpodFileServerGateway (Learn's
  AssetServerGateway): halkyon_base's files endpoint, taking the module's
  caller rather than Learn's client; FileLimitReached, FileRoom.
- Their fakes in halkyon_app's testing: MemoryFileCache,
  FakeFileServerGateway, sha256Of.
- SealedFile: the format every app seals a file in (HLKF, version 1),
  sealing with halkyon_app's ContentCipher; Learn's Privacy seals and
  opens its files with it, for the same context as before, so every file
  sealed so far opens as it did.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/learn/halkyon_learn_flutter/lib/src/core/asset/data/asset_file_cache.dart

@@ -1,101 +0,0 @@
-import 'dart:io';
-import 'dart:typed_data';
-
-import 'package:path/path.dart' as p;
-
-/// The files on this device, by their SHA-256, and which of them wait to be
-/// uploaded.
-abstract interface class AssetFileCache() {
-  /// The file with [sha256]; null if this device hasn't got it.
-  Future<Uint8List?> read(String sha256);
-
-  /// Keeps [bytes], whose SHA-256 is [sha256].
-  Future<void> write(String sha256, Uint8List bytes);
-
-  /// Where the file with [sha256] is, or would be.
-  String pathOf(String sha256);
-
-  /// The files that wait to be uploaded.
-  Future<Set<String>> pendingUploads();
-
-  /// Notes that the file with [sha256] waits to be uploaded.
-  Future<void> markPending(String sha256);
-
-  /// Notes that the file with [sha256] doesn't wait any more.
-  Future<void> clearPending(String sha256);
-}
-
-/// [AssetFileCache] in a folder of the person's: each file named by its hash,
-/// and an empty file of the same name in `uploads/` for each that waits.
-///
-/// A hash is part of a path here, and rows synced from elsewhere carry them,
-/// so anything but 64 lowercase hex digits is refused.
-class DirectoryAssetFileCache(final Directory _folder)
-    implements AssetFileCache {
-  Directory get _uploads => Directory(p.join(_folder.path, 'uploads'));
-
-  @override
-  Future<Uint8List?> read(String sha256) async {
-    try {
-      return await File(pathOf(sha256)).readAsBytes();
-    } on PathNotFoundException {
-      return null;
-    }
-  }
-
-  @override
-  Future<void> write(String sha256, Uint8List bytes) async {
-    final file = File(pathOf(sha256));
-    if (file.existsSync()) {
-      return;
-    }
-    await _folder.create(recursive: true);
-    // Written aside and renamed, so no half-written file ever has the name.
-    final partial = File('${file.path}.partial');
-    await partial.writeAsBytes(bytes, flush: true);
-    await partial.rename(file.path);
-  }
-
-  @override
-  String pathOf(String sha256) => p.join(_folder.path, checkedSha256(sha256));
-
-  @override
-  Future<Set<String>> pendingUploads() async {
-    if (!_uploads.existsSync()) {
-      return {};
-    }
-    return {
-      await for (final entry in _uploads.list())
-        if (entry is File && isSha256(p.basename(entry.path)))
-          p.basename(entry.path),
-    };
-  }
-
-  @override
-  Future<void> markPending(String sha256) async {
-    await _uploads.create(recursive: true);
-    await File(
-      p.join(_uploads.path, checkedSha256(sha256)),
-    ).writeAsBytes(const []);
-  }
-
-  @override
-  Future<void> clearPending(String sha256) async {
-    try {
-      await File(p.join(_uploads.path, checkedSha256(sha256))).delete();
-    } on PathNotFoundException {
-      // Not waiting.
-    }
-  }
-}
-
-/// Whether [value] is a SHA-256 as files are named by: 64 lowercase hex
-/// digits.
-bool isSha256(String value) => _sha256.hasMatch(value);
-
-/// [value], if it [isSha256]; throws an [ArgumentError] otherwise.
-String checkedSha256(String value) => isSha256(value)
-    ? value
-    : throw ArgumentError.value(value, 'sha256', 'is no SHA-256 in hex');
-
-final _sha256 = RegExp(r'^[0-9a-f]{64}$');

apps/learn/halkyon_learn_flutter/lib/src/core/asset/data/asset_repository.dart

@@ -3,13 +3,13 @@ import 'dart:developer';
 import 'dart:typed_data';
 
 import 'package:crypto/crypto.dart';
+import 'package:halkyon_app/halkyon_app.dart'
+    show FileCache, FileLimitReached, FileRoom, FileServerGateway, isSha256;
 import 'package:halkyon_core/halkyon_core.dart'
     show CoalescingRunner, SerialQueue;
-import 'package:halkyon_learn_flutter/src/core/asset/data/asset_file_cache.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_gateway.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_payload.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_sealing.dart';
-import 'package:halkyon_learn_flutter/src/core/asset/data/asset_server_gateway.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/model/stored_file.dart';
 import 'package:halkyon_learn_flutter/src/core/privacy/data/tree_files.dart';
 
@@ -33,8 +33,8 @@ import 'package:halkyon_learn_flutter/src/core/privacy/data/tree_files.dart';
 /// trees, is a file per key.
 class AssetRepository(
   final AssetGateway _rows,
-  final AssetServerGateway _server,
-  final AssetFileCache _files,
+  final FileServerGateway _server,
+  final FileCache _files,
   final AssetSealing _sealing, {
   Stream<void> uploadTriggers = const Stream.empty(),
 

apps/learn/halkyon_learn_flutter/lib/src/core/asset/data/asset_server_gateway.dart

@@ -1,45 +0,0 @@
-import 'dart:typed_data';
-
-/// How much room the person's files take on the server, and may take, in
-/// bytes.
-typedef FileRoom = ({int usedBytes, int limitBytes});
-
-/// The server keeps no more of the person's files: they would take more
-/// room than the person may use, or the instance has left ([instanceFull]).
-class const FileLimitReached({
-  /// Whether the instance is full, rather than the person's own room.
-  required final bool instanceFull,
-
-  /// What the person may keep, in bytes.
-  required final int limitBytes,
-}) implements Exception {
-  @override
-  String toString() =>
-      'FileLimitReached(instanceFull: $instanceFull, limit: $limitBytes)';
-}
-
-/// The server's copy of the person's files.
-abstract interface class AssetServerGateway() {
-  /// How to upload the file with [sha256] of [byteSize] bytes; null when the
-  /// server has it already. Throws [FileLimitReached] when it doesn't fit.
-  Future<String?> startUpload(
-    String sha256,
-    int byteSize, {
-    bool encrypted = false,
-  });
-
-  /// Uploads [bytes] as [description] says; whether that worked.
-  Future<bool> upload(String description, Uint8List bytes);
-
-  /// Completes the upload of the file with [sha256]; whether the server keeps
-  /// it, which it does only if its content has that hash. Throws
-  /// [FileLimitReached] when it no longer fits.
-  Future<bool> finishUpload(String sha256, {bool encrypted = false});
-
-  /// How much room the person's files take, and may take.
-  Future<FileRoom> room();
-
-  /// The file of the asset [id]; null when the server has none for this
-  /// person (not uploaded yet, or not theirs).
-  Future<Uint8List?> download(String id);
-}

apps/learn/halkyon_learn_flutter/lib/src/core/asset/data/serverpod_asset_server_gateway.dart

@@ -1,69 +0,0 @@
-import 'dart:typed_data';
-
-import 'package:halkyon_base_client/halkyon_base_client.dart' as base;
-import 'package:halkyon_learn_client/halkyon_learn_client.dart' as protocol;
-import 'package:halkyon_learn_flutter/src/core/asset/data/asset_server_gateway.dart';
-
-/// [AssetServerGateway] on halkyon_base's `files` endpoint (Halkyon's ADR
-/// 0043), uploading through Serverpod's own upload route. Learn's own
-/// `asset` endpoint stays for released apps alone (D7).
-class ServerpodAssetServerGateway(final protocol.Client _client)
-    implements AssetServerGateway {
-  @override
-  Future<String?> startUpload(
-    String sha256,
-    int byteSize, {
-    bool encrypted = false,
-  }) => _refusing(
-    () => _client.modules.base.files.startUpload(
-      sha256,
-      byteSize,
-      encrypted: encrypted,
-    ),
-  );
-
-  @override
-  Future<bool> upload(String description, Uint8List bytes) =>
-      protocol.FileUploader(description)
-          .uploadByteData(ByteData.sublistView(bytes));
-
-  @override
-  Future<bool> finishUpload(String sha256, {bool encrypted = false}) =>
-      _refusing(
-        () => _client.modules.base.files.finishUpload(
-          sha256,
-          encrypted: encrypted,
-        ),
-      );
-
-  @override
-  Future<FileRoom> room() async {
-    final usage = await _client.modules.base.files.usage();
-    return (usedBytes: usage.usedBytes, limitBytes: usage.limitBytes);
-  }
-
-  /// [call], its refusal for want of room as a [FileLimitReached].
-  Future<T> _refusing<T>(Future<T> Function() call) async {
-    try {
-      return await call();
-    } on base.FileLimitExceededException catch (error) {
-      throw FileLimitReached(
-        instanceFull: error.instanceFull,
-        limitBytes: error.limitBytes,
-      );
-    }
-  }
-
-  @override
-  Future<Uint8List?> download(String id) async {
-    try {
-      return Uint8List.sublistView(
-        await _client.modules.base.files.download(
-          protocol.UuidValue.withValidation(id),
-        ),
-      );
-    } on base.StoredFileNotFoundException {
-      return null;
-    }
-  }
-}

apps/learn/halkyon_learn_flutter/lib/src/core/dependencies/dependencies.dart

@@ -5,9 +5,7 @@ import 'package:flutter/widgets.dart';
 import 'package:halkyon_app/halkyon_app.dart';
 import 'package:halkyon_learn_client/halkyon_learn_client.dart'
     show Client, PublishRefusal, PublishRefusedException, UuidValue;
-import 'package:halkyon_learn_flutter/src/core/asset/data/asset_file_cache.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
-import 'package:halkyon_learn_flutter/src/core/asset/data/serverpod_asset_server_gateway.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/sound_player.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/sync_asset_gateway.dart';
 import 'package:halkyon_learn_flutter/src/core/dependencies/person_dependencies.dart';
@@ -541,8 +539,8 @@ Future<PersonDependencies> _openPersonData(
   )..start(sync.synced);
   final assets = AssetRepository(
     SyncAssetGateway(db, sync, privacy),
-    ServerpodAssetServerGateway(client),
-    DirectoryAssetFileCache(Directory(p.join(folder.path, 'files'))),
+    ServerpodFileServerGateway(client.modules.base),
+    DirectoryFileCache(Directory(p.join(folder.path, 'files'))),
     privacy,
     uploadTriggers: sync.synced,
     filesAllowed: () => sync.filesAllowed,

apps/learn/halkyon_learn_flutter/lib/src/core/privacy/data/privacy.dart

@@ -2365,63 +2365,21 @@ class Privacy(
       ? utf8.decode(Uint8List.sublistView(envelope.payload))
       : base64Encode(Uint8List.sublistView(envelope.payload));
 
-  /// What a sealed file starts with, and its format's version.
-  static final _fileMagic = utf8.encode('HLKF');
-  static const _fileVersion = 1;
-
   @override
   Uint8List sealFile(
     Uint8List plain, {
     required String keyId,
     required String assetId,
-  }) {
-    final sealed = keys.cipher.seal(
-      plain,
-      keyId: keyId,
-      context: _fileContext(assetId),
-    );
-    final id = utf8.encode(keyId);
-    return Uint8List.fromList([
-      ..._fileMagic,
-      _fileVersion,
-      id.length,
-      ...id,
-      ...sealed.nonce,
-      ...sealed.payload,
-    ]);
-  }
+  }) => SealedFile.seal(
+    keys.cipher,
+    plain,
+    keyId: keyId,
+    context: _fileContext(assetId),
+  );
 
   @override
-  Uint8List? openFile(Uint8List sealed, {required String assetId}) {
-    final header = _fileMagic.length + 2;
-    if (sealed.length < header ||
-        !_startsWith(sealed, _fileMagic) ||
-        sealed[_fileMagic.length] != _fileVersion) {
-      return null;
-    }
-    final idLength = sealed[_fileMagic.length + 1];
-    const nonceLength = 24;
-    if (sealed.length < header + idLength + nonceLength) {
-      return null;
-    }
-    final String keyId;
-    try {
-      keyId = utf8.decode(
-        Uint8List.sublistView(sealed, header, header + idLength),
-      );
-    } on FormatException {
-      return null;
-    }
-    final nonceAt = header + idLength;
-    return keys.cipher.unseal(
-      SealedPayload(
-        keyId: keyId,
-        nonce: Uint8List.sublistView(sealed, nonceAt, nonceAt + nonceLength),
-        payload: Uint8List.sublistView(sealed, nonceAt + nonceLength),
-      ),
-      context: _fileContext(assetId),
-    );
-  }
+  Uint8List? openFile(Uint8List sealed, {required String assetId}) =>
+      SealedFile.open(keys.cipher, sealed, context: _fileContext(assetId));
 
   static List<int> _fileContext(String assetId) =>
       utf8.encode('asset|$assetId|file');

apps/learn/halkyon_learn_flutter/test/core/asset/bloc/sound_bloc_test.dart

@@ -2,26 +2,26 @@ import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/testing.dart'
+    show FakeFileServerGateway, MemoryFileCache, sha256Of;
 import 'package:halkyon_learn_flutter/src/core/asset/bloc/sound_bloc.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
 
 import '../../../support/fake_asset_gateway.dart';
 import '../../../support/fake_asset_sealing.dart';
-import '../../../support/fake_asset_server_gateway.dart';
 import '../../../support/fake_sound_player.dart';
-import '../../../support/memory_asset_file_cache.dart';
 
 void main() {
-  late MemoryAssetFileCache files;
+  late MemoryFileCache files;
   late AssetRepository assets;
   late FakeSoundPlayer player;
   late String sound;
 
   setUp(() async {
-    files = MemoryAssetFileCache();
+    files = MemoryFileCache();
     assets = AssetRepository(
       FakeAssetGateway(),
-      FakeAssetServerGateway(),
+      FakeFileServerGateway(),
       files,
       FakeAssetSealing(),
     );

apps/learn/halkyon_learn_flutter/test/core/asset/data/asset_repository_test.dart

@@ -3,19 +3,19 @@ import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/testing.dart'
+    show FakeFileServerGateway, MemoryFileCache, sha256Of;
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_payload.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/model/stored_file.dart';
 
 import '../../../support/fake_asset_gateway.dart';
 import '../../../support/fake_asset_sealing.dart';
-import '../../../support/fake_asset_server_gateway.dart';
-import '../../../support/memory_asset_file_cache.dart';
 
 void main() {
   late FakeAssetGateway rows;
-  late FakeAssetServerGateway server;
-  late MemoryAssetFileCache cache;
+  late FakeFileServerGateway server;
+  late MemoryFileCache cache;
   late StreamController<void> triggers;
   late AssetRepository repository;
 
@@ -26,8 +26,8 @@ void main() {
 
   setUp(() {
     rows = FakeAssetGateway();
-    server = FakeAssetServerGateway();
-    cache = MemoryAssetFileCache();
+    server = FakeFileServerGateway();
+    cache = MemoryFileCache();
     triggers = StreamController<void>.broadcast();
     filesAllowed = true;
     repository = AssetRepository(

apps/learn/halkyon_learn_flutter/test/core/asset/data/directory_asset_file_cache_test.dart

@@ -1,62 +0,0 @@
-import 'dart:io';
-import 'dart:typed_data';
-
-import 'package:flutter_test/flutter_test.dart';
-import 'package:halkyon_learn_flutter/src/core/asset/data/asset_file_cache.dart';
-import 'package:path/path.dart' as p;
-
-void main() {
-  late Directory folder;
-  late DirectoryAssetFileCache cache;
-  final hash = 'a' * 64;
-  final other = 'b' * 64;
-
-  setUp(() async {
-    folder = await Directory.systemTemp.createTemp('files');
-    cache = DirectoryAssetFileCache(Directory(p.join(folder.path, 'files')));
-  });
-  tearDown(() => folder.delete(recursive: true));
-
-  test('keeps a file by its hash, and has none it was not given', () async {
-    expect(await cache.read(hash), isNull);
-
-    await cache.write(hash, Uint8List.fromList([1, 2, 3]));
-
-    expect(await cache.read(hash), [1, 2, 3]);
-    expect(File(cache.pathOf(hash)).readAsBytesSync(), [1, 2, 3]);
-    expect(
-      Directory(p.join(folder.path, 'files')).listSync().map((e) => e.path),
-      [cache.pathOf(hash)],
-      reason: 'nothing half-written is left beside it',
-    );
-  });
-
-  test('keeps the file it has when given it again', () async {
-    await cache.write(hash, Uint8List.fromList([1]));
-    await cache.write(hash, Uint8List.fromList([2]));
-
-    expect(await cache.read(hash), [1]);
-  });
-
-  test('notes which files wait to be uploaded', () async {
-    expect(await cache.pendingUploads(), isEmpty);
-
-    await cache.markPending(hash);
-    await cache.markPending(other);
-    await cache.clearPending(hash);
-    await cache.clearPending('c' * 64);
-
-    expect(await cache.pendingUploads(), {other});
-  });
-
-  test('refuses anything but a SHA-256 in a path', () async {
-    for (final forged in ['../sync.sqlite', 'A' * 64, '${'a' * 63}/', '']) {
-      expect(() => cache.pathOf(forged), throwsArgumentError);
-      await expectLater(cache.markPending(forged), throwsArgumentError);
-      await expectLater(
-        cache.write(forged, Uint8List.fromList([1])),
-        throwsArgumentError,
-      );
-    }
-  });
-}

apps/learn/halkyon_learn_flutter/test/core/asset/data/sealed_files_test.dart

@@ -2,19 +2,19 @@ import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/testing.dart'
+    show FakeFileServerGateway, MemoryFileCache, sha256Of;
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_payload.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
 
 import '../../../support/fake_asset_gateway.dart';
 import '../../../support/fake_asset_sealing.dart';
-import '../../../support/fake_asset_server_gateway.dart';
-import '../../../support/memory_asset_file_cache.dart';
 
 /// A private studyset's files (ADR 0019, D5): sealed with its tree's key for
 /// their row before they are hashed, uploaded and kept.
 void main() {
   late FakeAssetGateway rows;
-  late FakeAssetServerGateway server;
+  late FakeFileServerGateway server;
   late FakeAssetSealing sealing;
   late AssetRepository device;
   final image = Uint8List.fromList(utf8.encode('a private picture'));
@@ -26,7 +26,7 @@ void main() {
     final repository = AssetRepository(
       rows,
       server,
-      MemoryAssetFileCache(),
+      MemoryFileCache(),
       keys,
     );
     addTearDown(repository.dispose);
@@ -35,7 +35,7 @@ void main() {
 
   setUp(() {
     rows = FakeAssetGateway();
-    server = FakeAssetServerGateway();
+    server = FakeFileServerGateway();
     sealing = FakeAssetSealing(keys: {'diary': 'key-diary'});
     device = deviceWith(sealing);
   });

apps/learn/halkyon_learn_flutter/test/core/editor/editor_blocks_test.dart

@@ -15,7 +15,6 @@ import 'package:material_ui/material_ui.dart';
 import '../../support/fake_asset_gateway.dart';
 import '../../support/fake_note_gateway.dart';
 import '../../support/fake_studyset_gateway.dart';
-import '../../support/memory_asset_file_cache.dart';
 import '../../support/pump_app.dart';
 import '../../support/test_dependencies.dart';
 
@@ -44,7 +43,7 @@ void main() {
         noteGateway: FakeNoteGateway(),
         files: files,
         assetGateway: assets,
-        assetFiles: MemoryAssetFileCache(),
+        assetFiles: MemoryFileCache(),
       ),
       location: RoutePaths.newNote('japanese'),
     );

apps/learn/halkyon_learn_flutter/test/core/editor/file_blocks_test.dart

@@ -3,6 +3,8 @@ import 'dart:typed_data';
 
 import 'package:appflowy_editor/appflowy_editor.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/testing.dart'
+    show FakeFileServerGateway, MemoryFileCache, sha256Of;
 import 'package:halkyon_editor/halkyon_editor.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_payload.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
@@ -17,11 +19,9 @@ import 'package:material_ui/material_ui.dart';
 
 import '../../support/fake_asset_gateway.dart';
 import '../../support/fake_asset_sealing.dart';
-import '../../support/fake_asset_server_gateway.dart';
 import '../../support/fake_card_gateway.dart';
 import '../../support/fake_sound_player.dart';
 import '../../support/fake_studyset_gateway.dart';
-import '../../support/memory_asset_file_cache.dart';
 import '../../support/pump_app.dart';
 import '../../support/test_dependencies.dart';
 
@@ -29,7 +29,7 @@ void main() {
   late FakeCardGateway cardGateway;
   late CardRepository cards;
   late FakeAssetGateway assetGateway;
-  late MemoryAssetFileCache files;
+  late MemoryFileCache files;
   late AssetRepository assets;
   late FakeSoundPlayer sounds;
 
@@ -37,10 +37,10 @@ void main() {
     cardGateway = FakeCardGateway();
     cards = CardRepository(cardGateway);
     assetGateway = FakeAssetGateway();
-    files = MemoryAssetFileCache();
+    files = MemoryFileCache();
     assets = AssetRepository(
       assetGateway,
-      FakeAssetServerGateway(),
+      FakeFileServerGateway(),
       files,
       FakeAssetSealing(),
     );

apps/learn/halkyon_learn_flutter/test/feature/anki/data/anki_importer_test.dart

@@ -1,6 +1,8 @@
 import 'dart:io';
 
 import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/testing.dart'
+    show FakeFileServerGateway, MemoryFileCache;
 import 'package:halkyon_editor/halkyon_editor.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
 import 'package:halkyon_learn_flutter/src/core/work/work_progress.dart';
@@ -22,7 +24,6 @@ import 'package:halkyon_learn_flutter/src/feature/tag/data/tag_repository.dart';
 
 import '../../../support/fake_asset_gateway.dart';
 import '../../../support/fake_asset_sealing.dart';
-import '../../../support/fake_asset_server_gateway.dart';
 import '../../../support/fake_card_gateway.dart';
 import '../../../support/fake_learning_path_gateway.dart';
 import '../../../support/fake_note_gateway.dart';
@@ -30,7 +31,6 @@ import '../../../support/fake_pdf_source_gateway.dart';
 import '../../../support/fake_review_gateway.dart';
 import '../../../support/fake_studyset_gateway.dart';
 import '../../../support/fake_tag_gateway.dart';
-import '../../../support/memory_asset_file_cache.dart';
 import 'anki_package_test.dart' show fixture;
 
 void main() {
@@ -55,8 +55,8 @@ void main() {
     assetRows = FakeAssetGateway();
     assets = AssetRepository(
       assetRows,
-      FakeAssetServerGateway(),
-      MemoryAssetFileCache(),
+      FakeFileServerGateway(),
+      MemoryFileCache(),
       FakeAssetSealing(),
     );
     importer = AnkiImporter(

apps/learn/halkyon_learn_flutter/test/feature/anki/widget/anki_import_sheet_test.dart

@@ -15,7 +15,6 @@ import 'package:halkyon_learn_flutter/src/feature/studyset/data/studyset_reposit
 import 'package:halkyon_learn_flutter/src/feature/studyset/model/studyset_content.dart';
 import 'package:material_ui/material_ui.dart';
 
-import '../../../support/fake_asset_server_gateway.dart';
 import '../../../support/fake_card_gateway.dart';
 import '../../../support/fake_note_gateway.dart';
 import '../../../support/fake_studyset_gateway.dart';
@@ -26,13 +25,13 @@ import '../data/anki_package_test.dart' show fixture;
 void main() {
   late FakeCardGateway cardGateway;
   late FakeFilePicker files;
-  late FakeAssetServerGateway server;
+  late FakeFileServerGateway server;
   late FakeNoteGateway noteGateway;
 
   setUp(() {
     cardGateway = FakeCardGateway();
     files = FakeFilePicker();
-    server = FakeAssetServerGateway();
+    server = FakeFileServerGateway();
     noteGateway = FakeNoteGateway();
   });
 

apps/learn/halkyon_learn_flutter/test/feature/archive/archive_export_test.dart

@@ -3,6 +3,8 @@ import 'dart:typed_data';
 
 import 'package:clock/clock.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/testing.dart'
+    show FakeFileServerGateway, MemoryFileCache;
 import 'package:halkyon_editor/halkyon_editor.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/model/stored_file.dart';
@@ -40,7 +42,6 @@ import 'package:halkyon_ui/halkyon_ui.dart';
 
 import '../../support/fake_asset_gateway.dart';
 import '../../support/fake_asset_sealing.dart';
-import '../../support/fake_asset_server_gateway.dart';
 import '../../support/fake_card_gateway.dart';
 import '../../support/fake_device_dictionaries.dart';
 import '../../support/fake_dictionary_gateway.dart';
@@ -51,7 +52,6 @@ import '../../support/fake_pdf_source_gateway.dart';
 import '../../support/fake_review_gateway.dart';
 import '../../support/fake_studyset_gateway.dart';
 import '../../support/fake_tag_gateway.dart';
-import '../../support/memory_asset_file_cache.dart';
 
 /// One person's repositories, on fake gateways of their own.
 final class _Person() {
@@ -63,8 +63,8 @@ final class _Person() {
   final reviews = ReviewRepository(FakeReviewGateway());
   final assets = AssetRepository(
     FakeAssetGateway(),
-    FakeAssetServerGateway(),
-    MemoryAssetFileCache(),
+    FakeFileServerGateway(),
+    MemoryFileCache(),
     FakeAssetSealing(),
   );
   late final tags = TagRepository(

apps/learn/halkyon_learn_flutter/test/feature/archive/archive_test.dart

@@ -4,6 +4,8 @@ import 'dart:typed_data';
 import 'package:archive/archive.dart';
 import 'package:crypto/crypto.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/testing.dart'
+    show FakeFileServerGateway, MemoryFileCache;
 import 'package:halkyon_editor/halkyon_editor.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
 import 'package:halkyon_learn_flutter/src/core/work/work_progress.dart';
@@ -33,7 +35,6 @@ import 'package:halkyon_learn_flutter/src/feature/tag/data/tag_repository.dart';
 
 import '../../support/fake_asset_gateway.dart';
 import '../../support/fake_asset_sealing.dart';
-import '../../support/fake_asset_server_gateway.dart';
 import '../../support/fake_card_gateway.dart';
 import '../../support/fake_device_dictionaries.dart';
 import '../../support/fake_dictionary_gateway.dart';
@@ -44,7 +45,6 @@ import '../../support/fake_pdf_source_gateway.dart';
 import '../../support/fake_review_gateway.dart';
 import '../../support/fake_studyset_gateway.dart';
 import '../../support/fake_tag_gateway.dart';
-import '../../support/memory_asset_file_cache.dart';
 
 /// The JSON a synced [payload] holds.
 Map<String, Object?> json(ByteData payload) =>
@@ -280,8 +280,8 @@ void main() {
       assetRows = FakeAssetGateway();
       assets = AssetRepository(
         assetRows,
-        FakeAssetServerGateway(),
-        MemoryAssetFileCache(),
+        FakeFileServerGateway(),
+        MemoryFileCache(),
         FakeAssetSealing(),
       );
       pdfs = PdfSourceRepository(FakePdfSourceGateway(), assets);

apps/learn/halkyon_learn_flutter/test/feature/assistant/card_proposals_sheet_test.dart

@@ -20,13 +20,11 @@ import 'package:material_ui/material_ui.dart' hide Card;
 
 import '../../support/fake_asset_gateway.dart';
 import '../../support/fake_asset_sealing.dart';
-import '../../support/fake_asset_server_gateway.dart';
 import '../../support/fake_card_gateway.dart';
 import '../../support/fake_note_gateway.dart';
 import '../../support/fake_pdf_engine.dart';
 import '../../support/fake_pdf_source_gateway.dart';
 import '../../support/fake_studyset_gateway.dart';
-import '../../support/memory_asset_file_cache.dart';
 import '../../support/pump_app.dart';
 import '../../support/test_dependencies.dart';
 
@@ -74,7 +72,7 @@ void main() {
   late FakeNoteGateway noteGateway;
   late FakePdfSourceGateway pdfGateway;
   late FakeAssetGateway assetGateway;
-  late MemoryAssetFileCache files;
+  late MemoryFileCache files;
   late FakePdfEngine engine;
 
   setUp(() {
@@ -95,7 +93,7 @@ void main() {
     noteGateway = FakeNoteGateway();
     pdfGateway = FakePdfSourceGateway();
     assetGateway = FakeAssetGateway();
-    files = MemoryAssetFileCache();
+    files = MemoryFileCache();
     engine = FakePdfEngine();
   });
 
@@ -240,7 +238,7 @@ void main() {
       'selected, tied to the page', (tester) async {
     final assets = AssetRepository(
       assetGateway,
-      FakeAssetServerGateway(),
+      FakeFileServerGateway(),
       files,
       FakeAssetSealing(),
     );

apps/learn/halkyon_learn_flutter/test/feature/assistant/conversation_test.dart

@@ -29,14 +29,12 @@ import 'package:material_ui/material_ui.dart';
 
 import '../../support/fake_asset_gateway.dart';
 import '../../support/fake_asset_sealing.dart';
-import '../../support/fake_asset_server_gateway.dart';
 import '../../support/fake_card_gateway.dart';
 import '../../support/fake_conversation_gateway.dart';
 import '../../support/fake_grammar_gateway.dart';
 import '../../support/fake_photo_picker.dart';
 import '../../support/fake_settings_gateway.dart';
 import '../../support/fake_studyset_gateway.dart';
-import '../../support/memory_asset_file_cache.dart';
 import '../../support/memory_device_settings_store.dart';
 import '../../support/pump_app.dart';
 import '../../support/test_dependencies.dart';
@@ -123,7 +121,7 @@ void main() {
   late MemoryDeviceSettingsStore store;
   late List<Uri> searched;
   late FakeAssetGateway assetGateway;
-  late MemoryAssetFileCache assetFiles;
+  late MemoryFileCache assetFiles;
   late FakeGrammarGateway grammar;
 
   setUp(() {
@@ -150,7 +148,7 @@ void main() {
     speech = FakeSpeechInput();
     searched = [];
     assetGateway = FakeAssetGateway();
-    assetFiles = MemoryAssetFileCache();
+    assetFiles = MemoryFileCache();
     grammar = FakeGrammarGateway(
       found: {
         '私はりんごは食べる': const [
@@ -1469,7 +1467,7 @@ void main() {
     Future<String> picturedCard() async {
       final assets = AssetRepository(
         assetGateway,
-        FakeAssetServerGateway(),
+        FakeFileServerGateway(),
         assetFiles,
         FakeAssetSealing(),
       );

apps/learn/halkyon_learn_flutter/test/feature/assistant/data/assistant_files_test.dart

@@ -3,15 +3,15 @@ import 'dart:typed_data';
 import 'dart:ui' show Rect;
 
 import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/testing.dart'
+    show FakeFileServerGateway, MemoryFileCache;
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
 import 'package:halkyon_learn_flutter/src/feature/assistant/data/assistant_files.dart';
 import 'package:halkyon_learn_flutter/src/feature/pdf_source/model/pdf_source.dart';
 
 import '../../../support/fake_asset_gateway.dart';
 import '../../../support/fake_asset_sealing.dart';
-import '../../../support/fake_asset_server_gateway.dart';
 import '../../../support/fake_pdf_engine.dart';
-import '../../../support/memory_asset_file_cache.dart';
 
 // What a model is sent of the person's files (ADR 0021, D12): images every
 // provider reads, none larger than the smallest limit, and a PDF's pages
@@ -25,8 +25,8 @@ void main() {
   setUp(() {
     assets = AssetRepository(
       FakeAssetGateway(),
-      FakeAssetServerGateway(),
-      MemoryAssetFileCache(),
+      FakeFileServerGateway(),
+      MemoryFileCache(),
       FakeAssetSealing(),
     );
     engine = FakePdfEngine();

apps/learn/halkyon_learn_flutter/test/feature/explore/copy_update_banner_test.dart

@@ -2,6 +2,8 @@ import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_app/testing.dart'
+    show FakeFileServerGateway, MemoryFileCache;
 import 'package:halkyon_editor/halkyon_editor.dart';
 import 'package:halkyon_learn_flutter/src/core/asset/data/asset_repository.dart';
 import 'package:halkyon_learn_flutter/src/core/content/published_ref.dart';
@@ -24,7 +26,6 @@ import 'package:material_ui/material_ui.dart' hide Card;
 
 import '../../support/fake_asset_gateway.dart';
 import '../../support/fake_asset_sealing.dart';
-import '../../support/fake_asset_server_gateway.dart';
 import '../../support/fake_card_gateway.dart';
 import '../../support/fake_explore_gateway.dart';
 import '../../support/fake_learning_path_gateway.dart';
@@ -32,7 +33,6 @@ import '../../support/fake_note_gateway.dart';
 import '../../support/fake_pdf_source_gateway.dart';
 import '../../support/fake_studyset_gateway.dart';
 import '../../support/fake_tag_gateway.dart';
-import '../../support/memory_asset_file_cache.dart';
 import '../../support/pump_app.dart';
 import '../../support/test_dependencies.dart';
 
@@ -95,8 +95,8 @@ void main() {
     final paths = LearningPathRepository(FakeLearningPathGateway());
     final assets = AssetRepository(
       FakeAssetGateway(),
-      FakeAssetServerGateway(),
-      MemoryAssetFileCache(),
+      FakeFileServerGateway(),
+      MemoryFileCache(),
       FakeAssetSealing(),
     );
     // The person added release 1 to their library before.