Reland: [flutter_tools] File system utilities

packages/flutter_tools/lib/runner.dart

@@ -17,7 +17,6 @@ import 'src/base/io.dart';
 import 'src/base/logger.dart';
 import 'src/base/process.dart';
 import 'src/base/terminal.dart';
-import 'src/base/utils.dart';
 import 'src/context_runner.dart';
 import 'src/doctor.dart';
 import 'src/globals.dart' as globals;
@@ -191,7 +190,7 @@ FileSystem crashFileSystem = const LocalFileSystem();
 
 /// Saves the crash report to a local file.
 Future<File> _createLocalCrashReport(List<String> args, dynamic error, StackTrace stackTrace, String doctorText) async {
-  File crashFile = getUniqueFile(crashFileSystem.currentDirectory, 'flutter', 'log');
+  File crashFile = fsUtils.getUniqueFile(crashFileSystem.currentDirectory, 'flutter', 'log');
 
   final StringBuffer buffer = StringBuffer();
 
@@ -211,7 +210,7 @@ Future<File> _createLocalCrashReport(List<String> args, dynamic error, StackTrac
     crashFile.writeAsStringSync(buffer.toString());
   } on FileSystemException catch (_) {
     // Fallback to the system temporary directory.
-    crashFile = getUniqueFile(crashFileSystem.systemTempDirectory, 'flutter', 'log');
+    crashFile = fsUtils.getUniqueFile(crashFileSystem.systemTempDirectory, 'flutter', 'log');
     try {
       crashFile.writeAsStringSync(buffer.toString());
     } on FileSystemException catch (e) {

packages/flutter_tools/lib/src/android/gradle_utils.dart

@@ -98,7 +98,7 @@ class GradleUtils {
 
   /// Injects the Gradle wrapper files if any of these files don't exist in [directory].
   void injectGradleWrapperIfNeeded(Directory directory) {
-    copyDirectorySync(
+    fsUtils.copyDirectorySync(
       globals.cache.getArtifactDirectory('gradle_wrapper'),
       directory,
       shouldCopyFile: (File sourceFile, File destinationFile) {
@@ -267,10 +267,10 @@ void updateLocalProperties({
   }
 
   if (androidSdk != null) {
-    changeIfNecessary('sdk.dir', escapePath(androidSdk.directory));
+    changeIfNecessary('sdk.dir', fsUtils.escapePath(androidSdk.directory));
   }
 
-  changeIfNecessary('flutter.sdk', escapePath(Cache.flutterRoot));
+  changeIfNecessary('flutter.sdk', fsUtils.escapePath(Cache.flutterRoot));
   if (buildInfo != null) {
     changeIfNecessary('flutter.buildMode', buildInfo.modeName);
     final String buildName = validatedBuildNameForPlatform(
@@ -296,7 +296,7 @@ void updateLocalProperties({
 void writeLocalProperties(File properties) {
   final SettingsFile settings = SettingsFile();
   if (androidSdk != null) {
-    settings.values['sdk.dir'] = escapePath(androidSdk.directory);
+    settings.values['sdk.dir'] = fsUtils.escapePath(androidSdk.directory);
   }
   settings.writeContents(properties);
 }

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

@@ -11,7 +11,10 @@ import 'utils.dart';
 class Config {
   Config([File configFile, Logger localLogger]) {
     final Logger loggerInstance = localLogger ?? globals.logger;
-    _configFile = configFile ?? globals.fs.file(globals.fs.path.join(userHomePath(), '.flutter_settings'));
+    _configFile = configFile ?? globals.fs.file(globals.fs.path.join(
+      fsUtils.userHomePath,
+      '.flutter_settings',
+    ));
     if (_configFile.existsSync()) {
       try {
         _values = castStringKeyedMap(json.decode(_configFile.readAsStringSync()));

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

@@ -4,108 +4,149 @@
 
 import 'package:file/file.dart';
 import 'package:meta/meta.dart';
+import 'package:platform/platform.dart';
 
 import '../globals.dart' as globals;
 import 'common.dart' show throwToolExit;
+import 'context.dart';
 
 export 'package:file/file.dart';
 export 'package:file/local.dart';
 
-/// Create the ancestor directories of a file path if they do not already exist.
-void ensureDirectoryExists(String filePath) {
-  final String dirPath = globals.fs.path.dirname(filePath);
-  if (globals.fs.isDirectorySync(dirPath)) {
-    return;
-  }
-  try {
-    globals.fs.directory(dirPath).createSync(recursive: true);
-  } on FileSystemException catch (e) {
-    throwToolExit('Failed to create directory "$dirPath": ${e.osError.message}');
-  }
+/// Exception indicating that a file that was expected to exist was not found.
+class FileNotFoundException implements IOException {
+  const FileNotFoundException(this.path);
+
+  final String path;
+
+  @override
+  String toString() => 'File not found: $path';
 }
 
-/// Creates `destDir` if needed, then recursively copies `srcDir` to `destDir`,
-/// invoking [onFileCopied], if specified, for each source/destination file pair.
-///
-/// Skips files if [shouldCopyFile] returns `false`.
-void copyDirectorySync(
-  Directory srcDir,
-  Directory destDir, {
-  bool shouldCopyFile(File srcFile, File destFile),
-  void onFileCopied(File srcFile, File destFile),
-}) {
-  if (!srcDir.existsSync()) {
-    throw Exception('Source directory "${srcDir.path}" does not exist, nothing to copy');
-  }
+final FileSystemUtils _defaultFileSystemUtils = FileSystemUtils(
+  fileSystem: globals.fs,
+  platform: globals.platform,
+);
+
+FileSystemUtils get fsUtils => context.get<FileSystemUtils>() ?? _defaultFileSystemUtils;
+
+/// Various convenience file system methods.
+class FileSystemUtils {
+  FileSystemUtils({
+    @required FileSystem fileSystem,
+    @required Platform platform,
+  }) : _fileSystem = fileSystem,
+       _platform = platform;
+
+  final FileSystem _fileSystem;
+
+  final Platform _platform;
 
-  if (!destDir.existsSync()) {
-    destDir.createSync(recursive: true);
+  /// Create the ancestor directories of a file path if they do not already exist.
+  void ensureDirectoryExists(String filePath) {
+    final String dirPath = _fileSystem.path.dirname(filePath);
+    if (_fileSystem.isDirectorySync(dirPath)) {
+      return;
+    }
+    try {
+      _fileSystem.directory(dirPath).createSync(recursive: true);
+    } on FileSystemException catch (e) {
+      throwToolExit('Failed to create directory "$dirPath": ${e.osError.message}');
+    }
   }
 
-  for (final FileSystemEntity entity in srcDir.listSync()) {
-    final String newPath = destDir.fileSystem.path.join(destDir.path, entity.basename);
-    if (entity is File) {
-      final File newFile = destDir.fileSystem.file(newPath);
-      if (shouldCopyFile != null && !shouldCopyFile(entity, newFile)) {
-        continue;
+  /// Creates `destDir` if needed, then recursively copies `srcDir` to
+  /// `destDir`, invoking [onFileCopied], if specified, for each
+  /// source/destination file pair.
+  ///
+  /// Skips files if [shouldCopyFile] returns `false`.
+  void copyDirectorySync(
+    Directory srcDir,
+    Directory destDir, {
+    bool shouldCopyFile(File srcFile, File destFile),
+    void onFileCopied(File srcFile, File destFile),
+  }) {
+    if (!srcDir.existsSync()) {
+      throw Exception('Source directory "${srcDir.path}" does not exist, nothing to copy');
+    }
+
+    if (!destDir.existsSync()) {
+      destDir.createSync(recursive: true);
+    }
+
+    for (final FileSystemEntity entity in srcDir.listSync()) {
+      final String newPath = destDir.fileSystem.path.join(destDir.path, entity.basename);
+      if (entity is File) {
+        final File newFile = destDir.fileSystem.file(newPath);
+        if (shouldCopyFile != null && !shouldCopyFile(entity, newFile)) {
+          continue;
+        }
+        newFile.writeAsBytesSync(entity.readAsBytesSync());
+        onFileCopied?.call(entity, newFile);
+      } else if (entity is Directory) {
+        copyDirectorySync(
+          entity,
+          destDir.fileSystem.directory(newPath),
+          shouldCopyFile: shouldCopyFile,
+          onFileCopied: onFileCopied,
+        );
+      } else {
+        throw Exception('${entity.path} is neither File nor Directory');
       }
-      newFile.writeAsBytesSync(entity.readAsBytesSync());
-      onFileCopied?.call(entity, newFile);
-    } else if (entity is Directory) {
-      copyDirectorySync(
-        entity,
-        destDir.fileSystem.directory(newPath),
-        shouldCopyFile: shouldCopyFile,
-        onFileCopied: onFileCopied,
-      );
-    } else {
-      throw Exception('${entity.path} is neither File nor Directory');
     }
   }
-}
 
-/// Canonicalizes [path].
-///
-/// This function implements the behavior of `canonicalize` from
-/// `package:path`. However, unlike the original, it does not change the ASCII
-/// case of the path. Changing the case can break hot reload in some situations,
-/// for an example see: https://github.com/flutter/flutter/issues/9539.
-String canonicalizePath(String path) => globals.fs.path.normalize(globals.fs.path.absolute(path));
-
-/// Escapes [path].
-///
-/// On Windows it replaces all '\' with '\\'. On other platforms, it returns the
-/// path unchanged.
-String escapePath(String path) => globals.platform.isWindows ? path.replaceAll('\\', '\\\\') : path;
-
-/// Returns true if the file system [entity] has not been modified since the
-/// latest modification to [referenceFile].
-///
-/// Returns true, if [entity] does not exist.
-///
-/// Returns false, if [entity] exists, but [referenceFile] does not.
-bool isOlderThanReference({ @required FileSystemEntity entity, @required File referenceFile }) {
-  if (!entity.existsSync()) {
-    return true;
+  /// Appends a number to a filename in order to make it unique under a
+  /// directory.
+  File getUniqueFile(Directory dir, String baseName, String ext) {
+    final FileSystem fs = dir.fileSystem;
+    int i = 1;
+
+    while (true) {
+      final String name = '${baseName}_${i.toString().padLeft(2, '0')}.$ext';
+      final File file = fs.file(_fileSystem.path.join(dir.path, name));
+      if (!file.existsSync()) {
+        return file;
+      }
+      i++;
+    }
   }
-  return referenceFile.existsSync()
-      && referenceFile.statSync().modified.isAfter(entity.statSync().modified);
-}
 
-/// Exception indicating that a file that was expected to exist was not found.
-class FileNotFoundException implements IOException {
-  const FileNotFoundException(this.path);
+  /// Return a relative path if [fullPath] is contained by the cwd, else return an
+  /// absolute path.
+  String getDisplayPath(String fullPath) {
+    final String cwd = _fileSystem.currentDirectory.path + _fileSystem.path.separator;
+    return fullPath.startsWith(cwd) ? fullPath.substring(cwd.length) : fullPath;
+  }
 
-  final String path;
+  /// Escapes [path].
+  ///
+  /// On Windows it replaces all '\' with '\\'. On other platforms, it returns the
+  /// path unchanged.
+  String escapePath(String path) => _platform.isWindows ? path.replaceAll('\\', '\\\\') : path;
 
-  @override
-  String toString() => 'File not found: $path';
-}
+  /// Returns true if the file system [entity] has not been modified since the
+  /// latest modification to [referenceFile].
+  ///
+  /// Returns true, if [entity] does not exist.
+  ///
+  /// Returns false, if [entity] exists, but [referenceFile] does not.
+  bool isOlderThanReference({
+    @required FileSystemEntity entity,
+    @required File referenceFile,
+  }) {
+    if (!entity.existsSync()) {
+      return true;
+    }
+    return referenceFile.existsSync()
+        && referenceFile.statSync().modified.isAfter(entity.statSync().modified);
+  }
 
-/// Reads the process environment to find the current user's home directory.
-///
-/// If the searched environment variables are not set, '.' is returned instead.
-String userHomePath() {
-  final String envKey = globals.platform.operatingSystem == 'windows' ? 'APPDATA' : 'HOME';
-  return globals.platform.environment[envKey] ?? '.';
+  /// Reads the process environment to find the current user's home directory.
+  ///
+  /// If the searched environment variables are not set, '.' is returned instead.
+  String get userHomePath {
+    final String envKey = _platform.operatingSystem == 'windows' ? 'APPDATA' : 'HOME';
+    return _platform.environment[envKey] ?? '.';
+  }
 }

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

@@ -33,6 +33,7 @@ import 'dart:io' as io
     InternetAddressType,
     IOSink,
     NetworkInterface,
+    pid,
     Process,
     ProcessInfo,
     ProcessSignal,
@@ -252,6 +253,14 @@ Stream<List<int>> get stdin => globals.stdio.stdin;
 io.IOSink get stderr => globals.stdio.stderr;
 bool get stdinHasTerminal => globals.stdio.stdinHasTerminal;
 
+// TODO(zra): Move pid and writePidFile into `ProcessInfo`.
+void writePidFile(String pidFile) {
+  if (pidFile != null) {
+    // Write our pid to the file.
+    globals.fs.file(pidFile).writeAsStringSync(io.pid.toString());
+  }
+}
+
 /// An overridable version of io.ProcessInfo.
 abstract class ProcessInfo {
   factory ProcessInfo() => _DefaultProcessInfo();

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

@@ -9,9 +9,7 @@ import 'package:intl/intl.dart';
 import 'package:meta/meta.dart';
 
 import '../convert.dart';
-import '../globals.dart' as globals;
 import 'file_system.dart';
-import 'io.dart' as io;
 import 'terminal.dart';
 
 /// Convert `foo_bar` to `fooBar`.
@@ -51,29 +49,10 @@ String getEnumName(dynamic enumItem) {
   return index == -1 ? name : name.substring(index + 1);
 }
 
-File getUniqueFile(Directory dir, String baseName, String ext) {
-  final FileSystem fs = dir.fileSystem;
-  int i = 1;
-
-  while (true) {
-    final String name = '${baseName}_${i.toString().padLeft(2, '0')}.$ext';
-    final File file = fs.file(globals.fs.path.join(dir.path, name));
-    if (!file.existsSync()) {
-      return file;
-    }
-    i++;
-  }
-}
-
 String toPrettyJson(Object jsonable) {
   return const JsonEncoder.withIndent('  ').convert(jsonable) + '\n';
 }
 
-/// Return a String - with units - for the size in MB of the given number of bytes.
-String getSizeAsMB(int bytesLength) {
-  return '${(bytesLength / (1024 * 1024)).toStringAsFixed(1)}MB';
-}
-
 final NumberFormat kSecondsFormat = NumberFormat('0.0');
 final NumberFormat kMillisecondsFormat = NumberFormat.decimalPattern();
 
@@ -86,11 +65,9 @@ String getElapsedAsMilliseconds(Duration duration) {
   return '${kMillisecondsFormat.format(duration.inMilliseconds)}ms';
 }
 
-/// Return a relative path if [fullPath] is contained by the cwd, else return an
-/// absolute path.
-String getDisplayPath(String fullPath) {
-  final String cwd = globals.fs.currentDirectory.path + globals.fs.path.separator;
-  return fullPath.startsWith(cwd) ? fullPath.substring(cwd.length) : fullPath;
+/// Return a String - with units - for the size in MB of the given number of bytes.
+String getSizeAsMB(int bytesLength) {
+  return '${(bytesLength / (1024 * 1024)).toStringAsFixed(1)}MB';
 }
 
 /// A class to maintain a list of items, fire events when items are added or
@@ -315,13 +292,6 @@ String wrapText(String text, { int columnWidth, int hangingIndent, int indent, b
   return result.join('\n');
 }
 
-void writePidFile(String pidFile) {
-  if (pidFile != null) {
-    // Write our pid to the file.
-    globals.fs.file(pidFile).writeAsStringSync(io.pid.toString());
-  }
-}
-
 // Used to represent a run of ANSI control sequences next to a visible
 // character.
 class _AnsiRun {