refactor: move status cache to a separate file

scripts/flutter_symbol_collector/bin/flutter_symbol_collector.dart

@@ -5,13 +5,13 @@ import 'package:github/github.dart';
 import 'package:logging/logging.dart';
 
 const githubToken = String.fromEnvironment('GITHUB_TOKEN');
-final source = FlutterSymbolSource(
-    githubAuth: githubToken.isEmpty
-        ? Authentication.anonymous()
-        : Authentication.withToken(githubToken));
+final githubAuth = githubToken.isEmpty
+    ? Authentication.anonymous()
+    : Authentication.withToken(githubToken);
+final source = FlutterSymbolSource(githubAuth: githubAuth);
 final fs = LocalFileSystem();
 final tempDir = fs.currentDirectory.childDirectory('.temp');
-final successDir = fs.currentDirectory.childDirectory('.successful');
+final stateCache = DirectoryStatusCache(fs.currentDirectory.childDirectory('.successful'));
 late final SymbolCollectorCli collector;
 
 void main(List<String> arguments) async {
@@ -26,7 +26,6 @@ void main(List<String> arguments) async {
   final argVersion = args['version'] as String;
 
   collector = await SymbolCollectorCli.setup(tempDir);
-  successDir.createSync(recursive: true);
 
   // If a specific version was given, run just for this version.
   if (argVersion.isNotEmpty &&
@@ -62,25 +61,22 @@ Future<void> processFlutterVerion(FlutterVersion version) async {
 
   final archives = await source.listSymbolArchives(version);
   final dir = tempDir.childDirectory(version.tagName);
-  final sdir = successDir.childDirectory(version.tagName.toLowerCase());
   for (final archive in archives) {
-    // Later, we'll write create an empty file to mark this as successful.
-    final sFile = sdir.childFile(archive.path.toLowerCase());
-    if (sFile.existsSync()) {
+    final status = await stateCache.getStatus(archive);
+    if (status == SymbolArchiveStatus.success) {
       Logger.root
           .info('Skipping ${archive.path} - already processed successfully');
       continue;
     }
 
     final archiveDir = dir.childDirectory(archive.platform.operatingSystem);
-    if (!await source.downloadAndExtractTo(archiveDir, archive.path)) {
-      continue;
-    }
-    if (!await collector.upload(archiveDir, archive.platform, version)) {
-      continue;
+    if (await source.downloadAndExtractTo(archiveDir, archive.path)) {
+      if (await collector.upload(archiveDir, archive.platform, version)) {
+        await stateCache.setStatus(archive, SymbolArchiveStatus.success);
+        continue;
+      }
     }
-
-    sFile.createSync(recursive: true);
+    await stateCache.setStatus(archive, SymbolArchiveStatus.error);
   }
 
   if (bool.hasEnvironment('CI')) {

scripts/flutter_symbol_collector/lib/flutter_symbol_collector.dart

@@ -1,3 +1,4 @@
 export 'src/flutter_symbol_source.dart';
 export 'src/flutter_version.dart';
 export 'src/symbol_collector_cli.dart';
+export 'src/status_cache.dart';

scripts/flutter_symbol_collector/lib/src/status_cache.dart

@@ -0,0 +1,56 @@
+import 'package:file/file.dart';
+import 'package:github/github.dart' as github;
+import 'package:logging/logging.dart';
+
+import 'symbol_archive.dart';
+
+enum SymbolArchiveStatus {
+  /// The archive has been successfully processed.
+  success,
+
+  /// The archive has been processed but there was an error.
+  error,
+
+  /// The archive hasn't been processed yet
+  pending,
+}
+
+/// Stores and retrieves information about symbol processing status.
+abstract class SymbolArchiveStatusCache {
+  Future<void> setStatus(SymbolArchive archive, SymbolArchiveStatus status);
+  Future<SymbolArchiveStatus> getStatus(SymbolArchive archive);
+}
+
+/// Stores information about symbol processing status in a local directory.
+class DirectoryStatusCache implements SymbolArchiveStatusCache {
+  final Directory _dir;
+
+  DirectoryStatusCache(this._dir) {
+    _dir.createSync(recursive: true);
+  }
+
+  File _statusFile(SymbolArchive archive) =>
+      _dir.childFile(archive.path.toLowerCase());
+
+  @override
+  Future<SymbolArchiveStatus> getStatus(SymbolArchive archive) async {
+    final file = _statusFile(archive);
+    if (!await file.exists()) {
+      return SymbolArchiveStatus.pending;
+    }
+    return file.readAsString().then((value) {
+      switch (value) {
+        case 'success':
+          return SymbolArchiveStatus.success;
+        case 'error':
+          return SymbolArchiveStatus.error;
+        default:
+          throw StateError('Unknown status: $value');
+      }
+    });
+  }
+
+  @override
+  Future<void> setStatus(SymbolArchive archive, SymbolArchiveStatus status) =>
+      _statusFile(archive).writeAsString(status.toString());
+}