use IOOverrides to allow inject file system, write test, find bug (#40066)

packages/flutter_tools/lib/src/base/io.dart

@@ -26,7 +26,8 @@
 /// increase the API surface that we have to test in Flutter tools, and the APIs
 /// in `dart:io` can sometimes be hard to use in tests.
 import 'dart:async';
-import 'dart:io' as io show exit, IOSink, Process, ProcessInfo, ProcessSignal, stderr, stdin, Stdout, stdout;
+import 'dart:io' as io show exit, IOSink, Process, ProcessInfo, ProcessSignal,
+    stderr, stdin, Stdout, stdout;
 
 import 'package:meta/meta.dart';
 
@@ -38,10 +39,10 @@ export 'dart:io'
     show
         BytesBuilder,
         CompressionOptions,
-        // Directory         NO! Use `file_system.dart`
+        // Directory,         NO! Use `file_system.dart`
         exitCode,
-        // File              NO! Use `file_system.dart`
-        // FileSystemEntity  NO! Use `file_system.dart`
+        // File,              NO! Use `file_system.dart`
+        // FileSystemEntity,  NO! Use `file_system.dart`
         gzip,
         HandshakeException,
         HttpClient,

packages/flutter_tools/lib/src/build_runner/web_compilation_delegate.dart

@@ -125,20 +125,20 @@ class MultirootFileBasedAssetReader extends core.FileBasedAssetReader {
   @override
   Stream<AssetId> findAssets(Glob glob, {String package}) async* {
     if (package == null || packageGraph.root.name == package) {
+      final String generatedRoot = fs.path.join(
+        generatedDirectory.path, packageGraph.root.name
+      );
       await for (io.FileSystemEntity entity in glob.list(followLinks: true, root: packageGraph.root.path)) {
-        if (entity is io.File && _isNotHidden(entity)) {
+        if (entity is io.File && _isNotHidden(entity) && !fs.path.isWithin(generatedRoot, entity.path)) {
           yield _fileToAssetId(entity, packageGraph.root);
         }
       }
-      final String generatedRoot = fs.path.join(
-        generatedDirectory.path, packageGraph.root.name,
-      );
       if (!fs.isDirectorySync(generatedRoot)) {
         return;
       }
       await for (io.FileSystemEntity entity in glob.list(followLinks: true, root: generatedRoot)) {
         if (entity is io.File && _isNotHidden(entity)) {
-          yield _fileToAssetId(entity, packageGraph.root, generatedRoot);
+          yield _fileToAssetId(entity, packageGraph.root, fs.path.relative(generatedRoot), true);
         }
       }
       return;
@@ -161,9 +161,14 @@ class MultirootFileBasedAssetReader extends core.FileBasedAssetReader {
   }
 
   /// Creates an [AssetId] for [file], which is a part of [packageNode].
-  AssetId _fileToAssetId(io.File file, core.PackageNode packageNode, [String root]) {
+  AssetId _fileToAssetId(io.File file, core.PackageNode packageNode, [String root, bool generated = false]) {
     final String filePath = path.normalize(file.absolute.path);
-    final String relativePath = path.relative(filePath, from: root ?? packageNode.path);
+    String relativePath;
+    if (generated) {
+      relativePath = filePath.substring(root.length + 2);
+    } else {
+      relativePath = path.relative(filePath, from: packageNode.path);
+    }
     return AssetId(packageNode.name, relativePath);
   }
 }

packages/flutter_tools/test/general.shard/base/io_test.dart

@@ -5,16 +5,56 @@
 import 'dart:async';
 import 'dart:io' as io;
 
+import 'package:file/memory.dart';
 import 'package:flutter_tools/src/base/io.dart';
 import 'package:mockito/mockito.dart';
 
 import '../../src/common.dart';
 import '../../src/context.dart';
+import '../../src/io.dart';
 
 void main() {
-  group('ProcessSignal', () {
+  test('IOOverrides can inject a memory file system', () async {
+    final MemoryFileSystem memoryFileSystem = MemoryFileSystem();
+    final FlutterIOOverrides flutterIOOverrides = FlutterIOOverrides(fileSystem: memoryFileSystem);
+    await io.IOOverrides.runWithIOOverrides(() async {
+      // statics delegate correctly.
+      expect(io.FileSystemEntity.isWatchSupported, memoryFileSystem.isWatchSupported);
+      expect(io.Directory.systemTemp.path, memoryFileSystem.systemTempDirectory.path);
 
-    testUsingContext('signals are properly delegated', () async {
+      // can create and write to files/directories sync.
+      final io.File file = io.File('abc');
+      file.writeAsStringSync('def');
+      final io.Directory directory = io.Directory('foobar');
+      directory.createSync();
+
+      expect(memoryFileSystem.file('abc').existsSync(), true);
+      expect(memoryFileSystem.file('abc').readAsStringSync(), 'def');
+      expect(memoryFileSystem.directory('foobar').existsSync(), true);
+
+      // can create and write to files/directories async.
+      final io.File fileB = io.File('xyz');
+      await fileB.writeAsString('def');
+      final io.Directory directoryB = io.Directory('barfoo');
+      await directoryB.create();
+
+      expect(memoryFileSystem.file('xyz').existsSync(), true);
+      expect(memoryFileSystem.file('xyz').readAsStringSync(), 'def');
+      expect(memoryFileSystem.directory('barfoo').existsSync(), true);
+
+      // Links
+      final io.Link linkA = io.Link('hhh');
+      final io.Link linkB = io.Link('ggg');
+      io.File('jjj').createSync();
+      io.File('lll').createSync();
+      await linkA.create('jjj');
+      linkB.createSync('lll');
+
+      expect(await memoryFileSystem.link('hhh').resolveSymbolicLinks(), await linkA.resolveSymbolicLinks());
+      expect(memoryFileSystem.link('ggg').resolveSymbolicLinksSync(), linkB.resolveSymbolicLinksSync());
+    }, flutterIOOverrides);
+  });
+  testUsingContext('ProcessSignal signals are properly delegated', () async {
     final MockIoProcessSignal mockSignal = MockIoProcessSignal();
     final ProcessSignal signalUnderTest = ProcessSignal(mockSignal);
     final StreamController<io.ProcessSignal> controller = StreamController<io.ProcessSignal>();
@@ -25,10 +65,9 @@ void main() {
     expect(signalUnderTest, await signalUnderTest.watch().first);
   });
 
-    testUsingContext('toString() works', () async {
+  testUsingContext('ProcessSignal toString() works', () async {
     expect(io.ProcessSignal.sigint.toString(), ProcessSignal.SIGINT.toString());
   });
-  });
 }
 
 class MockIoProcessSignal extends Mock implements io.ProcessSignal {}

packages/flutter_tools/test/general.shard/build_runner/multiroot_asset_reader_test.dart

@@ -3,13 +3,16 @@
 // found in the LICENSE file.
 
 import 'dart:convert';
+import 'dart:io';
 
 import 'package:build/build.dart';
 import 'package:build_runner_core/build_runner_core.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/build_runner/web_compilation_delegate.dart';
+import 'package:glob/glob.dart';
 
 import '../../src/common.dart';
+import '../../src/io.dart';
 import '../../src/testbed.dart';
 
 void main() {
@@ -34,17 +37,30 @@ void main() {
     });
 
     test('Can find assets from the generated directory', () => testbed.run(() async {
+      await IOOverrides.runWithIOOverrides(() async {
         final MultirootFileBasedAssetReader reader = MultirootFileBasedAssetReader(
           packageGraph,
-        fs.directory(fs.path.join('.dart_tool', 'build', 'generated')),
+          fs.directory(fs.path.join('.dart_tool', 'build', 'generated'))
         );
-
-      // Note: we can't read from the regular directory because the default
-      // asset reader uses the regular file system.
         expect(await reader.canRead(AssetId('foobar', 'lib/bar.dart')), true);
+        expect(await reader.canRead(AssetId('foobar', 'lib/main.dart')), true);
+
         expect(await reader.readAsString(AssetId('foobar', 'lib/bar.dart')), 'bar');
+        expect(await reader.readAsString(AssetId('foobar', 'lib/main.dart')), 'main');
+
         expect(await reader.readAsBytes(AssetId('foobar', 'lib/bar.dart')), utf8.encode('bar'));
-    }));
+        expect(await reader.readAsBytes(AssetId('foobar', 'lib/main.dart')), utf8.encode('main'));
+
+        expect(await reader.findAssets(Glob('**')).toList(), unorderedEquals(<AssetId>[
+          AssetId('foobar', 'pubspec.yaml'),
+          AssetId('foobar', 'lib/bar.dart'),
+          AssetId('foobar', 'lib/main.dart'),
+        ]));
+      }, FlutterIOOverrides(fileSystem: fs));
+     // Some component of either dart:io or build_runner normalizes file uris
+     // into file paths for windows. This doesn't seem to work with IOOverrides
+     // leaving all filepaths on windows with forward slashes.
+    }), skip: Platform.isWindows);
   });
 }
 

packages/flutter_tools/test/src/io.dart

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:io' as io show IOOverrides, Directory, File, Link;
+
+import 'package:flutter_tools/src/base/file_system.dart';
+
+/// An [IOOverrides] that can delegate to [FileSystem] implementation if provided.
+///
+/// Does not override any of the socket facilities.
+///
+/// Do not provide a [LocalFileSystem] as a delegate. Since internally this calls
+/// out to `dart:io` classes, it will result in a stack overflow error as the
+/// IOOverrides and LocalFileSystem call eachother endlessly.
+///
+/// The only safe delegate types are those that do not call out to `dart:io`,
+/// like the [MemoryFileSystem].
+class FlutterIOOverrides extends io.IOOverrides {
+  FlutterIOOverrides({ FileSystem fileSystem })
+    : _fileSystemDelegate = fileSystem;
+
+  final FileSystem _fileSystemDelegate;
+
+  @override
+  io.Directory createDirectory(String path) {
+    if (_fileSystemDelegate == null) {
+      return super.createDirectory(path);
+    }
+    return _fileSystemDelegate.directory(path);
+  }
+
+  @override
+  io.File createFile(String path) {
+    if (_fileSystemDelegate == null) {
+      return super.createFile(path);
+    }
+    return _fileSystemDelegate.file(path);
+  }
+
+  @override
+  io.Link createLink(String path) {
+    if (_fileSystemDelegate == null) {
+      return super.createLink(path);
+    }
+    return _fileSystemDelegate.link(path);
+  }
+
+  @override
+  Stream<FileSystemEvent> fsWatch(String path, int events, bool recursive) {
+    if (_fileSystemDelegate == null) {
+      return super.fsWatch(path, events, recursive);
+    }
+    return _fileSystemDelegate.file(path).watch(events: events, recursive: recursive);
+  }
+
+  @override
+  bool fsWatchIsSupported() {
+    if (_fileSystemDelegate == null) {
+      return super.fsWatchIsSupported();
+    }
+    return _fileSystemDelegate.isWatchSupported;
+  }
+
+  @override
+  Future<FileSystemEntityType> fseGetType(String path, bool followLinks) {
+    if (_fileSystemDelegate == null) {
+      return super.fseGetType(path, followLinks);
+    }
+    return _fileSystemDelegate.type(path, followLinks: followLinks ?? true);
+  }
+
+  @override
+  FileSystemEntityType fseGetTypeSync(String path, bool followLinks) {
+    if (_fileSystemDelegate == null) {
+      return super.fseGetTypeSync(path, followLinks);
+    }
+    return _fileSystemDelegate.typeSync(path, followLinks: followLinks ?? true);
+  }
+
+  @override
+  Future<bool> fseIdentical(String path1, String path2) {
+    if (_fileSystemDelegate == null) {
+      return super.fseIdentical(path1, path2);
+    }
+    return _fileSystemDelegate.identical(path1, path2);
+  }
+
+  @override
+  bool fseIdenticalSync(String path1, String path2) {
+    if (_fileSystemDelegate == null) {
+      return super.fseIdenticalSync(path1, path2);
+    }
+    return _fileSystemDelegate.identicalSync(path1, path2);
+  }
+
+  @override
+  io.Directory getCurrentDirectory() {
+    if (_fileSystemDelegate == null) {
+      return super.getCurrentDirectory();
+    }
+    return _fileSystemDelegate.currentDirectory;
+  }
+
+  @override
+  io.Directory getSystemTempDirectory() {
+    if (_fileSystemDelegate == null) {
+      return super.getSystemTempDirectory();
+    }
+    return _fileSystemDelegate.systemTempDirectory;
+  }
+
+  @override
+  void setCurrentDirectory(String path) {
+    if (_fileSystemDelegate == null) {
+      return super.setCurrentDirectory(path);
+    }
+    _fileSystemDelegate.currentDirectory = path;
+  }
+
+  @override
+  Future<FileStat> stat(String path) {
+    if (_fileSystemDelegate == null) {
+      return super.stat(path);
+    }
+    return _fileSystemDelegate.stat(path);
+  }
+
+  @override
+  FileStat statSync(String path) {
+    if (_fileSystemDelegate == null) {
+      return super.statSync(path);
+    }
+    return _fileSystemDelegate.statSync(path);
+  }
+}