Add writeAsStringSync (issue 27109)

pkg/analyzer/lib/file_system/memory_file_system.dart

Index: pkg/analyzer/lib/file_system/memory_file_system.dart
diff --git a/pkg/analyzer/lib/file_system/memory_file_system.dart b/pkg/analyzer/lib/file_system/memory_file_system.dart
index dbc41d14b75d257e351f63763872e6f8a569687e..51d635bed2900e42359453db08c8e1887cfda938 100644
--- a/pkg/analyzer/lib/file_system/memory_file_system.dart
+++ b/pkg/analyzer/lib/file_system/memory_file_system.dart
@@ -23,7 +23,6 @@ class MemoryResourceProvider implements ResourceProvider {
   final Map<String, _MemoryResource> _pathToResource =
       new HashMap<String, _MemoryResource>();
   final Map<String, String> _pathToContent = new HashMap<String, String>();
-  final Map<String, List<int>> _pathToBytes = new HashMap<String, List<int>>();
   final Map<String, int> _pathToTimestamp = new HashMap<String, int>();
   final Map<String, List<StreamController<WatchEvent>>> _pathToWatchers =
       new HashMap<String, List<StreamController<WatchEvent>>>();
@@ -135,7 +134,7 @@ class MemoryResourceProvider implements ResourceProvider {
   File newFileWithBytes(String path, List<int> bytes, [int stamp]) {
     path = pathContext.normalize(path);
     _MemoryFile file = _newFile(path);
-    _pathToBytes[path] = bytes;
+    _pathToContent[path] = new String.fromCharCodes(bytes);
     _pathToTimestamp[path] = stamp ?? nextStamp++;
     _notifyWatchers(path, ChangeType.ADD);
     return file;
@@ -180,7 +179,6 @@ class MemoryResourceProvider implements ResourceProvider {
     _MemoryFile newFile = _newFile(newPath);
     _pathToResource.remove(path);
     _pathToContent[newPath] = _pathToContent.remove(path);
-    _pathToBytes[newPath] = _pathToBytes.remove(path);
     _pathToTimestamp[newPath] = _pathToTimestamp.remove(path);
     if (existingNewResource != null) {
       _notifyWatchers(newPath, ChangeType.REMOVE);
@@ -245,10 +243,10 @@ class MemoryResourceProvider implements ResourceProvider {
     });
   }
 
-  void _setFileBytes(_MemoryFile file, List<int> bytes) {
+  void _setFileContent(_MemoryFile file, String content) {
     String path = file.path;
     _pathToResource[path] = file;
-    _pathToBytes[path] = bytes;
+    _pathToContent[path] = content;
     _pathToTimestamp[path] = nextStamp++;
     _notifyWatchers(path, ChangeType.MODIFY);
   }
@@ -316,6 +314,11 @@ class _MemoryDummyLink extends _MemoryResource implements File {
   void writeAsBytesSync(List<int> bytes) {
     throw new FileSystemException(path, 'File could not be written');
   }
+
+  @override
+  void writeAsStringSync(String content) {
+    throw new FileSystemException(path, 'File could not be written');
+  }
 }
 
 /**
@@ -355,11 +358,11 @@ class _MemoryFile extends _MemoryResource implements File {
 
   @override
   List<int> readAsBytesSync() {
-    List<int> bytes = _provider._pathToBytes[path];
-    if (bytes == null) {
-      throw new FileSystemException(path, 'File "$path" is not binary.');
+    String content = _provider._pathToContent[path];
+    if (content == null) {
+      throw new FileSystemException(path, 'File "$path" does not exist.');
     }
-    return bytes;
+    return content.codeUnits;
   }
 
   @override
@@ -381,7 +384,12 @@ class _MemoryFile extends _MemoryResource implements File {
 
   @override
   void writeAsBytesSync(List<int> bytes) {
-    _provider._setFileBytes(this, bytes);
+    _provider._setFileContent(this, new String.fromCharCodes(bytes));
+  }
+
+  @override
+  void writeAsStringSync(String content) {
+    _provider._setFileContent(this, content);
   }
 }