Add more API fuzzing and fix the issues encountered.

runtime/bin/file_impl.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class _FileInputStream extends _BaseDataInputStream implements InputStream {
   _FileInputStream(String name) {
     var file = new File(name);
     _data = [];
     _position = 0;
     var chained = file.open(FileMode.READ).chain((openedFile) {
@@ skipping 632 matching lines @@
     var read = opened.readListSync(result, 0, length);
     if (read != length) {
       throw new FileIOException("Failed to read file");
     }
     opened.closeSync();
     return result;
   }
 
   Future<String> readAsText([Encoding encoding = Encoding.UTF_8]) {
     _ensureFileService();
-    var decoder = _StringDecoders.decoder(encoding);
     return readAsBytes().transform((bytes) {
+      var decoder = _StringDecoders.decoder(encoding);
       decoder.write(bytes);
       return decoder.decoded;
     });
   }
 
   String readAsTextSync([Encoding encoding = Encoding.UTF_8]) {
     var decoder = _StringDecoders.decoder(encoding);
     List<int> bytes = readAsBytesSync();
     decoder.write(bytes);
     return decoder.decoded;
@@ skipping 11 matching lines @@
     var data = decoder.decoded;
     if (data != null) {
       result.add(data);
     }
     return result;
   }
 
   Future<List<String>> readAsLines([Encoding encoding = Encoding.UTF_8]) {
     _ensureFileService();
     Completer<List<String>> completer = new Completer<List<String>>();
-    var decoder = _StringDecoders.decoder(encoding);
     return readAsBytes().transform((bytes) {
+      var decoder = _StringDecoders.decoder(encoding);
       decoder.write(bytes);
       return _getDecodedLines(decoder);
     });
   }
 
   List<String> readAsLinesSync([Encoding encoding = Encoding.UTF_8]) {
     var decoder = _StringDecoders.decoder(encoding);
     List<int> bytes = readAsBytesSync();
     decoder.write(bytes);
     return _getDecodedLines(decoder);
@@ skipping 11 matching lines @@
 
   SendPort _fileService;
 }
 
 
 class _RandomAccessFile extends _FileBase implements RandomAccessFile {
   _RandomAccessFile(int this._id, String this._name);
 
   Future<RandomAccessFile> close() {
     Completer<RandomAccessFile> completer = new Completer<RandomAccessFile>();
-    if (_id == 0) {
-      // Complete asynchronously so the user has a chance to setup
-      // handlers without getting exceptions when registering the
-      // then handler.
-      new Timer(0, (t) {
-        completer.completeException(
-            new FileIOException("Cannot close file '$_name'"));
-      });
-      return completer.future;
-    }
+    if (_isClosed) return _completeWithClosedException(completer);
     _ensureFileService();
     List request = new List(2);
     request[0] = _FileUtils.kCloseRequest;
     request[1] = _id;
     // Set the id_ to 0 (NULL) to ensure the no more async requests
     // can be issues for this file.
     _id = 0;
     _fileService.call(request).then((result) {
       if (result != -1) {
         _id = result;
@@ skipping 10 matching lines @@
     var id = _FileUtils.close(_id);
     if (id == -1) {
       throw new FileIOException("Cannot close file '$_name'");
     }
     _id = id;
   }
 
   Future<int> readByte() {
     _ensureFileService();
     Completer<int> completer = new Completer<int>();
+    if (_isClosed) return _completeWithClosedException(completer);
     List request = new List(2);
     request[0] = _FileUtils.kReadByteRequest;
     request[1] = _id;
     _fileService.call(request).then((response) {
       if (_isErrorResponse(response)) {
         var e = _exceptionFromResponse(response,
                                        "readByte failed for file '$_name'");
         completer.completeException(e);
       } else {
         completer.complete(response);
@@ skipping 17 matching lines @@
     if (buffer is !List || offset is !int || bytes is !int) {
       // Complete asynchronously so the user has a chance to setup
       // handlers without getting exceptions when registering the
       // then handler.
       new Timer(0, (t) {
         completer.completeException(new FileIOException(
             "Invalid arguments to readList for file '$_name'"));
       });
       return completer.future;
     };
+    if (_isClosed) return _completeWithClosedException(completer);
     List request = new List(3);
     request[0] = _FileUtils.kReadListRequest;
     request[1] = _id;
     request[2] = bytes;
     _fileService.call(request).then((response) {
       if (_isErrorResponse(response)) {
         var e = _exceptionFromResponse(response,
                                        "readList failed for file '$_name'");
         completer.completeException(e);
       } else {
@@ skipping 32 matching lines @@
     if (value is !int) {
       // Complete asynchronously so the user has a chance to setup
       // handlers without getting exceptions when registering the
       // then handler.
       new Timer(0, (t) {
           completer.completeException(new FileIOException(
               "Invalid argument to writeByte for file '$_name'"));
       });
       return completer.future;
     }
+    if (_isClosed) return _completeWithClosedException(completer);
     List request = new List(3);
     request[0] = _FileUtils.kWriteByteRequest;
     request[1] = _id;
     request[2] = value;
     _fileService.call(request).then((response) {
       if (_isErrorResponse(response)) {
         var e = _exceptionFromResponse(response,
                                        "writeByte failed for file '$_name'");
         completer.completeException(e);
       } else {
@@ skipping 23 matching lines @@
     if (buffer is !List || offset is !int || bytes is !int) {
       // Complete asynchronously so the user has a chance to setup
       // handlers without getting exceptions when registering the
       // then handler.
       new Timer(0, (t) {
           completer.completeException(new FileIOException(
           "Invalid arguments to writeList for file '$_name'"));
       });
       return completer.future;
     }
+    if (_isClosed) return _completeWithClosedException(completer);
 
     List result =
         _FileUtils.ensureFastAndSerializableBuffer(buffer, offset, bytes);
     List outBuffer = result[0];
     int outOffset = result[1];
 
     List request = new List(5);
     request[0] = _FileUtils.kWriteListRequest;
     request[1] = _id;
     request[2] = outBuffer;
@@ skipping 27 matching lines @@
     if (result is OSError) {
       throw new FileIOException("writeList failed for file '$_name'", result);
     }
     return result;
   }
 
   Future<RandomAccessFile> writeString(String string,
                                        [Encoding encoding = Encoding.UTF_8]) {
     _ensureFileService();
     Completer<RandomAccessFile> completer = new Completer<RandomAccessFile>();
+    if (_isClosed) return _completeWithClosedException(completer);
     List request = new List(3);
     request[0] = _FileUtils.kWriteStringRequest;
     request[1] = _id;
     request[2] = string;
     _fileService.call(request).then((response) {
       if (_isErrorResponse(response)) {
         var e = _exceptionFromResponse(response,
                                        "writeString failed for file '$_name'");
         completer.completeException(e);
       } else {
         completer.complete(this);
       }
     });
     return completer.future;
   }
 
   int writeStringSync(String string, [Encoding encoding = Encoding.UTF_8]) {
     _checkNotClosed();
     var result = _FileUtils.checkedWriteString(_id, string);
     if (result is OSError) {
       throw new FileIOException("writeString failed for file '$_name'", result);
     }
     return result;
   }
 
   Future<int> position() {
     _ensureFileService();
     Completer<int> completer = new Completer<int>();
+    if (_isClosed) return _completeWithClosedException(completer);
     List request = new List(2);
     request[0] = _FileUtils.kPositionRequest;
     request[1] = _id;
     _fileService.call(request).then((response) {
       if (_isErrorResponse(response)) {
         var e = _exceptionFromResponse(response,
                                        "position failed for file '$_name'");
         completer.completeException(e);
       } else {
         completer.complete(response);
       }
     });
     return completer.future;
   }
 
   int positionSync() {
     _checkNotClosed();
     var result = _FileUtils.position(_id);
     if (result is OSError) {
       throw new FileIOException("position failed for file '$_name'", result);
     }
     return result;
   }
 
   Future<RandomAccessFile> setPosition(int position) {
     _ensureFileService();
     Completer<RandomAccessFile> completer = new Completer<RandomAccessFile>();
+    if (_isClosed) return _completeWithClosedException(completer);
     List request = new List(3);
     request[0] = _FileUtils.kSetPositionRequest;
     request[1] = _id;
     request[2] = position;
     _fileService.call(request).then((response) {
       if (_isErrorResponse(response)) {
         var e = _exceptionFromResponse(response,
                                        "setPosition failed for file '$_name'");
         completer.completeException(e);
       } else {
         completer.complete(this);
       }
     });
     return completer.future;
   }
 
   void setPositionSync(int position) {
     _checkNotClosed();
     var result = _FileUtils.setPosition(_id, position);
     if (result is OSError) {
       throw new FileIOException("setPosition failed for file '$_name'", result);
     }
   }
 
   Future<RandomAccessFile> truncate(int length) {
     _ensureFileService();
     Completer<RandomAccessFile> completer = new Completer<RandomAccessFile>();
+    if (_isClosed) return _completeWithClosedException(completer);
     List request = new List(3);
     request[0] = _FileUtils.kTruncateRequest;
     request[1] = _id;
     request[2] = length;
     _fileService.call(request).then((response) {
       if (_isErrorResponse(response)) {
         var e = _exceptionFromResponse(response,
                                        "truncate failed for file '$_name'");
         completer.completeException(e);
       } else {
         completer.complete(this);
       }
     });
     return completer.future;
   }
 
   void truncateSync(int length) {
     _checkNotClosed();
     var result = _FileUtils.truncate(_id, length);
     if (result is OSError) {
       throw new FileIOException("truncate failed for file '$_name'", result);
     }
   }
 
   Future<int> length() {
     _ensureFileService();
     Completer<int> completer = new Completer<int>();
+    if (_isClosed) return _completeWithClosedException(completer);
     List request = new List(2);
     request[0] = _FileUtils.kLengthRequest;
     request[1] = _id;
     _fileService.call(request).then((response) {
       if (_isErrorResponse(response)) {
         var e = _exceptionFromResponse(response,
                                        "length failed for file '$_name'");
         completer.completeException(e);
       } else {
         completer.complete(response);
       }
     });
     return completer.future;
   }
 
   int lengthSync() {
     _checkNotClosed();
     var result = _FileUtils.length(_id);
     if (result is OSError) {
       throw new FileIOException("length failed for file '$_name'", result);
     }
     return result;
   }
 
   Future<RandomAccessFile> flush() {
     _ensureFileService();
     Completer<RandomAccessFile> completer = new Completer<RandomAccessFile>();
+    if (_isClosed) return _completeWithClosedException(completer);
     List request = new List(2);
     request[0] = _FileUtils.kFlushRequest;
     request[1] = _id;
     _fileService.call(request).then((response) {
       if (_isErrorResponse(response)) {
         var e = _exceptionFromResponse(response,
                                        "flush failed for file '$_name'");
         completer.completeException(e);
       } else {
         completer.complete(this);
@@ skipping 11 matching lines @@
   }
 
   String get name() => _name;
 
   void _ensureFileService() {
     if (_fileService == null) {
       _fileService = _FileUtils.newServicePort();
     }
   }
 
+  bool get _isClosed() => _id == 0;
+
   void _checkNotClosed() {
-    if (_id == 0) {
+    if (_isClosed) {
       throw new FileIOException("File closed '$_name'");
     }
   }
 
+  Future _completeWithClosedException(Completer completer) {
+    new Timer(0, (t) {
+      completer.completeException(
+          new FileIOException("File closed '$_name'"));
+    });
+    return completer.future;
+  }
+
   final String _name;
   int _id;
 
   SendPort _fileService;
 }