[native_assets_builder] Use package:files FileSystem abstraction (#1825)

The main motivation for this change is to make `package:native_assets_builder` cleanly usable in flutter tools. Right now flutter tools operates on a `FileSystem` and checks whether `.dart_tool/package_config.json` exists using that `FileSystem` but then reads the file with this packagag's code which uses `dart:io`.

This inconsistency causes issues in flutter tools. Using `package:file` should solve this and would also
allow injecting mocks. To be fully mockable the implementation would also need to make process invocations
mockable via `package:process`. That's a future task.

See also #90

Author: mkustermann

pkgs/native_assets_builder/CHANGELOG.md

@@ -4,6 +4,8 @@
 - Various fixes to caching.
 - **Breaking change** `BuildConfig.targetOS` is now only provided if
   `buildAssetTypes` contains the code asset.
+- **Breaking change** `NativeAssetsBuildRunner` and `PackageLayout` now take a
+  `FileSystem` from `package:file/file.dart`s.
 
 ## 0.9.0
 

pkgs/native_assets_builder/lib/src/build_runner/build_planner.dart

@@ -3,7 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:convert';
-import 'dart:io';
+import 'dart:io' show Process;
 
 import 'package:graphs/graphs.dart' as graphs;
 import 'package:logging/logging.dart';

pkgs/native_assets_builder/lib/src/build_runner/build_runner.dart

@@ -4,8 +4,9 @@
 
 import 'dart:async';
 import 'dart:convert';
-import 'dart:io';
+import 'dart:io' show Platform;
 
+import 'package:file/file.dart';
 import 'package:logging/logging.dart';
 import 'package:native_assets_cli/native_assets_cli_internal.dart';
 import 'package:package_config/package_config.dart';
@@ -63,15 +64,18 @@ typedef ApplicationAssetValidator = Future<ValidationErrors> Function(
 /// [BuildConfig] and [LinkConfig]! For more info see:
 /// https://github.com/dart-lang/native/issues/1319
 class NativeAssetsBuildRunner {
+  final FileSystem _fileSystem;
   final Logger logger;
   final Uri dartExecutable;
   final Duration singleHookTimeout;
 
   NativeAssetsBuildRunner({
     required this.logger,
     required this.dartExecutable,
+    required FileSystem fileSystem,
     Duration? singleHookTimeout,
-  }) : singleHookTimeout = singleHookTimeout ?? const Duration(minutes: 5);
+  })  : _fileSystem = fileSystem,
+        singleHookTimeout = singleHookTimeout ?? const Duration(minutes: 5);
 
   /// [workingDirectory] is expected to contain `.dart_tool`.
   ///
@@ -98,7 +102,8 @@ class NativeAssetsBuildRunner {
     required List<String> buildAssetTypes,
     required bool linkingEnabled,
   }) async {
-    packageLayout ??= await PackageLayout.fromRootPackageRoot(workingDirectory);
+    packageLayout ??=
+        await PackageLayout.fromRootPackageRoot(_fileSystem, workingDirectory);
 
     final (buildPlan, packageGraph) = await _makePlan(
       hook: Hook.build,
@@ -203,7 +208,8 @@ class NativeAssetsBuildRunner {
     required List<String> buildAssetTypes,
     required BuildResult buildResult,
   }) async {
-    packageLayout ??= await PackageLayout.fromRootPackageRoot(workingDirectory);
+    packageLayout ??=
+        await PackageLayout.fromRootPackageRoot(_fileSystem, workingDirectory);
 
     final (buildPlan, packageGraph) = await _makePlan(
       hook: Hook.link,
@@ -231,9 +237,9 @@ class NativeAssetsBuildRunner {
 
       File? resourcesFile;
       if (resourceIdentifiers != null) {
-        resourcesFile = File.fromUri(buildDirUri.resolve('resources.json'));
+        resourcesFile = _fileSystem.file(buildDirUri.resolve('resources.json'));
         await resourcesFile.create();
-        await File.fromUri(resourceIdentifiers).copy(resourcesFile.path);
+        await _fileSystem.file(resourceIdentifiers).copy(resourcesFile.path);
       }
       configBuilder.setupLinkRunConfig(
         outputDirectory: outDirUri,
@@ -291,14 +297,14 @@ class NativeAssetsBuildRunner {
     final buildDirUri =
         packageLayout.dartToolNativeAssetsBuilder.resolve('$buildDirName/');
     final outDirUri = buildDirUri.resolve('out/');
-    final outDir = Directory.fromUri(outDirUri);
+    final outDir = _fileSystem.directory(outDirUri);
     if (!await outDir.exists()) {
       // TODO(https://dartbug.com/50565): Purge old or unused folders.
       await outDir.create(recursive: true);
     }
     final outDirSharedUri = packageLayout.dartToolNativeAssetsBuilder
         .resolve('shared/${package.name}/$hook/');
-    final outDirShared = Directory.fromUri(outDirSharedUri);
+    final outDirShared = _fileSystem.directory(outDirSharedUri);
     if (!await outDirShared.exists()) {
       // TODO(https://dartbug.com/50565): Purge old or unused folders.
       await outDirShared.create(recursive: true);
@@ -318,9 +324,10 @@ class NativeAssetsBuildRunner {
     final environment = _filteredEnvironment(_environmentVariablesFilter);
     final outDir = config.outputDirectory;
     return await runUnderDirectoriesLock(
+      _fileSystem,
       [
-        Directory.fromUri(config.outputDirectoryShared.parent),
-        Directory.fromUri(config.outputDirectory.parent),
+        _fileSystem.directory(config.outputDirectoryShared).parent.uri,
+        _fileSystem.directory(config.outputDirectory).parent.uri,
       ],
       timeout: singleHookTimeout,
       logger: logger,
@@ -338,15 +345,13 @@ class NativeAssetsBuildRunner {
         final (hookKernelFile, hookHashes) = hookCompileResult;
 
         final buildOutputFile =
-            File.fromUri(config.outputDirectory.resolve(hook.outputName));
-        final dependenciesHashFile = File.fromUri(
-          config.outputDirectory
-              .resolve('../dependencies.dependencies_hash_file.json'),
-        );
+            _fileSystem.file(config.outputDirectory.resolve(hook.outputName));
+        final dependenciesHashFile = config.outputDirectory
+            .resolve('../dependencies.dependencies_hash_file.json');
         final dependenciesHashes =
-            DependenciesHashFile(file: dependenciesHashFile);
+            DependenciesHashFile(_fileSystem, fileUri: dependenciesHashFile);
         final lastModifiedCutoffTime = DateTime.now();
-        if (buildOutputFile.existsSync() && dependenciesHashFile.existsSync()) {
+        if (buildOutputFile.existsSync() && await dependenciesHashes.exists()) {
           late final HookOutput output;
           try {
             output = _readHookOutputFromUri(hook, buildOutputFile);
@@ -391,8 +396,8 @@ ${e.message}
           environment,
         );
         if (result == null) {
-          if (await dependenciesHashFile.exists()) {
-            await dependenciesHashFile.delete();
+          if (await dependenciesHashes.exists()) {
+            await dependenciesHashes.delete();
           }
           return null;
         } else {
@@ -446,9 +451,9 @@ ${e.message}
     final configFileContents =
         const JsonEncoder.withIndent(' ').convert(config.json);
     logger.info('config.json contents: $configFileContents');
-    await File.fromUri(configFile).writeAsString(configFileContents);
+    await _fileSystem.file(configFile).writeAsString(configFileContents);
     final hookOutputUri = config.outputDirectory.resolve(hook.outputName);
-    final hookOutputFile = File.fromUri(hookOutputUri);
+    final hookOutputFile = _fileSystem.file(hookOutputUri);
     if (await hookOutputFile.exists()) {
       // Ensure we'll never read outdated build results.
       await hookOutputFile.delete();
@@ -461,6 +466,7 @@ ${e.message}
       if (resources != null) resources.toFilePath(),
     ];
     final result = await runProcess(
+      filesystem: _fileSystem,
       workingDirectory: workingDirectory,
       executable: dartExecutable,
       arguments: arguments,
@@ -472,7 +478,8 @@ ${e.message}
     var deleteOutputIfExists = false;
     try {
       if (result.exitCode != 0) {
-        final printWorkingDir = workingDirectory != Directory.current.uri;
+        final printWorkingDir =
+            workingDirectory != _fileSystem.currentDirectory.uri;
         final commandString = [
           if (printWorkingDir) '(cd ${workingDirectory.toFilePath()};',
           dartExecutable.toFilePath(),
@@ -558,19 +565,19 @@ ${e.message}
   ) async {
     // Don't invalidate cache with environment changes.
     final environmentForCaching = <String, String>{};
-    final kernelFile = File.fromUri(
+    final kernelFile = _fileSystem.file(
       outputDirectory.resolve('../hook.dill'),
     );
-    final depFile = File.fromUri(
+    final depFile = _fileSystem.file(
       outputDirectory.resolve('../hook.dill.d'),
     );
-    final dependenciesHashFile = File.fromUri(
-      outputDirectory.resolve('../hook.dependencies_hash_file.json'),
-    );
-    final dependenciesHashes = DependenciesHashFile(file: dependenciesHashFile);
+    final dependenciesHashFile =
+        outputDirectory.resolve('../hook.dependencies_hash_file.json');
+    final dependenciesHashes =
+        DependenciesHashFile(_fileSystem, fileUri: dependenciesHashFile);
     final lastModifiedCutoffTime = DateTime.now();
     var mustCompile = false;
-    if (!await dependenciesHashFile.exists()) {
+    if (!await dependenciesHashes.exists()) {
       mustCompile = true;
     } else {
       final outdatedDependency = await dependenciesHashes
@@ -633,6 +640,7 @@ ${e.message}
       scriptUri.toFilePath(),
     ];
     final compileResult = await runProcess(
+      filesystem: _fileSystem,
       workingDirectory: workingDirectory,
       executable: dartExecutable,
       arguments: compileArguments,
@@ -641,7 +649,8 @@ ${e.message}
     );
     var success = true;
     if (compileResult.exitCode != 0) {
-      final printWorkingDir = workingDirectory != Directory.current.uri;
+      final printWorkingDir =
+          workingDirectory != _fileSystem.currentDirectory.uri;
       final commandString = [
         if (printWorkingDir) '(cd ${workingDirectory.toFilePath()};',
         dartExecutable.toFilePath(),
@@ -780,10 +789,6 @@ ${compileResult.stdout}
   }
 }
 
-extension on Uri {
-  Uri get parent => File(toFilePath()).parent.uri;
-}
-
 /// Parses depfile contents.
 ///
 /// Format: `path/to/my.dill: path/to/my.dart, path/to/more.dart`

pkgs/native_assets_builder/lib/src/dependencies_hash_file/dependencies_hash_file.dart

@@ -3,25 +3,32 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:convert';
-import 'dart:io';
+import 'dart:io' show Platform;
 import 'dart:typed_data';
 
 import 'package:crypto/crypto.dart';
+import 'package:file/file.dart';
 
 import '../utils/file.dart';
 import '../utils/uri.dart';
 
 class DependenciesHashFile {
-  DependenciesHashFile({
-    required this.file,
+  DependenciesHashFile(
+    this._fileSystem, {
+    required this.fileUri,
   });
 
-  final File file;
+  final FileSystem _fileSystem;
+  final Uri fileUri;
   FileSystemHashes _hashes = FileSystemHashes();
 
   List<Uri> get fileSystemEntities => _hashes.files.map((e) => e.path).toList();
 
+  Future<bool> exists() async => await _fileSystem.file(fileUri).exists();
+  Future<void> delete() async => await _fileSystem.file(fileUri).delete();
+
   Future<void> _readFile() async {
+    final file = _fileSystem.file(fileUri);
     if (!await file.exists()) {
       _hashes = FileSystemHashes();
       return;
@@ -51,7 +58,7 @@ class DependenciesHashFile {
     Uri? modifiedAfterTimeStamp;
     for (final uri in fileSystemEntities) {
       int hash;
-      if ((await uri.fileSystemEntity.lastModified())
+      if ((await _fileSystem.fileSystemEntity(uri).lastModified(_fileSystem))
           .isAfter(fileSystemValidBeforeLastModified)) {
         hash = _hashLastModifiedAfterCutoff;
         modifiedAfterTimeStamp = uri;
@@ -72,7 +79,8 @@ class DependenciesHashFile {
     return modifiedAfterTimeStamp;
   }
 
-  Future<void> _persist() => file.writeAsString(json.encode(_hashes.toJson()));
+  Future<void> _persist() =>
+      _fileSystem.file(fileUri).writeAsString(json.encode(_hashes.toJson()));
 
   /// Reads the file with hashes and reports if there is an outdated file,
   /// directory or environment variable.
@@ -124,15 +132,15 @@ class DependenciesHashFile {
   }
 
   Future<int> _hashFile(Uri uri) async {
-    final file = File.fromUri(uri);
+    final file = _fileSystem.file(uri);
     if (!await file.exists()) {
       return _hashNotExists;
     }
     return _md5int64(await file.readAsBytes());
   }
 
   Future<int> _hashDirectory(Uri uri) async {
-    final directory = Directory.fromUri(uri);
+    final directory = _fileSystem.directory(uri);
     if (!await directory.exists()) {
       return _hashNotExists;
     }

pkgs/native_assets_builder/lib/src/locking/locking.dart

@@ -3,12 +3,14 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:io';
+import 'dart:io' show Platform, pid;
+import 'package:file/file.dart';
 
 import 'package:logging/logging.dart';
 
 Future<T> runUnderDirectoriesLock<T>(
-  List<Directory> directories,
+  FileSystem fileSystem,
+  List<Uri> directories,
   Future<T> Function() callback, {
   Duration? timeout,
   Logger? logger,
@@ -17,8 +19,10 @@ Future<T> runUnderDirectoriesLock<T>(
     return await callback();
   }
   return await runUnderDirectoryLock(
+    fileSystem,
     directories.first,
     () => runUnderDirectoriesLock<T>(
+      fileSystem,
       directories.skip(1).toList(),
       callback,
       timeout: timeout,
@@ -41,13 +45,14 @@ Future<T> runUnderDirectoriesLock<T>(
 /// If provided, the [logger] streams information on the the locking status, and
 /// also streams error messages.
 Future<T> runUnderDirectoryLock<T>(
-  Directory directory,
+  FileSystem fileSystem,
+  Uri directory,
   Future<T> Function() callback, {
   Duration? timeout,
   Logger? logger,
 }) async {
   const lockFileName = '.lock';
-  final lockFile = _fileInDir(directory, lockFileName);
+  final lockFile = _fileInDir(fileSystem.directory(directory), lockFileName);
   return _runUnderFileLock(
     lockFile,
     callback,
@@ -60,7 +65,7 @@ File _fileInDir(Directory path, String filename) {
   final dirPath = path.path;
   var separator = Platform.pathSeparator;
   if (dirPath.endsWith(separator)) separator = '';
-  return File('$dirPath$separator$filename');
+  return path.fileSystem.file('$dirPath$separator$filename');
 }
 
 /// Run [callback] with this Dart process having exclusive access to [file].