Change dart:io to use Future for one-shot operations.

tests/standalone/io/file_error_test.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.
 //
 // Dart test program for testing error handling in file I/O.
 
 #import("dart:io");
 #import("dart:isolate");
 
 Directory tempDir() {
-  var d = new Directory('');
-  d.createTempSync();
-  return d;
+  return new Directory('').createTempSync();
 }
 
 
 bool checkNonExistentFileException(e, str) {
   Expect.isTrue(e is FileIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf(str) != -1);
   if (Platform.operatingSystem == "linux") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
   } else if (Platform.operatingSystem == "macos") {
@@ skipping 31 matching lines @@
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
   var file = new File("${temp.path}/nonExistentFile");
 
   // Non-existing file should throw exception.
   Expect.throws(() => file.openSync(),
                 (e) => checkOpenNonExistentFileException(e));
 
-  file.open(FileMode.READ, (raf) => Expect.fail("Unreachable code"));
-  file.onError = (e) {
+  var openFuture = file.open(FileMode.READ);
+  openFuture.then((raf) => Expect.fail("Unreachable code"));
+  openFuture.handleException((e) {
     checkOpenNonExistentFileException(e);
     p.toSendPort().send(null);
-  };
+    return true;
+  });
 }
 
 
 void testDeleteNonExistent() {
   Directory temp = tempDir();
   ReceivePort p = new ReceivePort();
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
   var file = new File("${temp.path}/nonExistentFile");
 
   // Non-existing file should throw exception.
   Expect.throws(() => file.deleteSync(),
                 (e) => checkDeleteNonExistentFileException(e));
 
-  file.delete(() => Expect.fail("Unreachable code"));
-  file.onError = (e) {
+  var delete = file.delete();
+  delete.then((ignore) => Expect.fail("Unreachable code"));
+  delete.handleException((e) {
     checkDeleteNonExistentFileException(e);
     p.toSendPort().send(null);
-  };
+    return true;
+  });
 }
 
 
 void testLengthNonExistent() {
   Directory temp = tempDir();
   ReceivePort p = new ReceivePort();
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
   var file = new File("${temp.path}/nonExistentFile");
 
   // Non-existing file should throw exception.
   Expect.throws(() => file.lengthSync(),
                 (e) => checkLengthNonExistentFileException(e));
 
-  file.length((len) => Expect.fail("Unreachable code"));
-  file.onError = (e) {
+  var lenFuture = file.length();
+  lenFuture.then((len) => Expect.fail("Unreachable code"));
+  lenFuture.handleException((e) {
     checkLengthNonExistentFileException(e);
     p.toSendPort().send(null);
-  };
+    return true;
+  });
 }
 
 
 bool checkCreateInNonExistentDirectoryException(e) {
   Expect.isTrue(e is FileIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf("Cannot create file") != -1);
   if (Platform.operatingSystem == "linux") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
@@ skipping 16 matching lines @@
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
   var file = new File("${temp.path}/nonExistentDirectory/newFile");
 
   // Create in non-existent directory should throw exception.
   Expect.throws(() => file.createSync(),
                 (e) => checkCreateInNonExistentDirectoryException(e));
 
-  file.create(() => Expect.fail("Unreachable code"));
-  file.onError = (e) {
+  var create = file.create();
+  create.then((ignore) => Expect.fail("Unreachable code"));
+  create.handleException((e) {
     checkCreateInNonExistentDirectoryException(e);
     p.toSendPort().send(null);
-  };
+    return true;
+  });
 }
 
 bool checkFullPathOnNonExistentDirectoryException(e) {
   Expect.isTrue(e is FileIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf("Cannot retrieve full path") != -1);
   if (Platform.operatingSystem == "linux") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
   } else if (Platform.operatingSystem == "macos") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
@@ skipping 14 matching lines @@
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
   var file = new File("${temp.path}/nonExistentDirectory");
 
   // Full path non-existent directory should throw exception.
   Expect.throws(() => file.fullPathSync(),
                 (e) => checkFullPathOnNonExistentDirectoryException(e));
 
-  file.fullPath((path) => Expect.fail("Unreachable code $path"));
-  file.onError = (e) {
+  var fullPathFuture = file.fullPath();
+  fullPathFuture.then((path) => Expect.fail("Unreachable code $path"));
+  fullPathFuture.handleException((e) {
     checkFullPathOnNonExistentDirectoryException(e);
     p.toSendPort().send(null);
-  };
+    return true;
+  });
 }
 
 bool checkDirectoryInNonExistentDirectoryException(e) {
   Expect.isTrue(e is FileIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(
       e.toString().indexOf("Cannot retrieve directory for file") != -1);
   if (Platform.operatingSystem == "linux") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
   } else if (Platform.operatingSystem == "macos") {
@@ skipping 15 matching lines @@
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
   var file = new File("${temp.path}/nonExistentDirectory/newFile");
 
   // Create in non-existent directory should throw exception.
   Expect.throws(() => file.directorySync(),
                 (e) => checkDirectoryInNonExistentDirectoryException(e));
 
-  file.directory((directory) => Expect.fail("Unreachable code"));
-  file.onError = (e) {
+  var dirFuture = file.directory();
+  dirFuture.then((directory) => Expect.fail("Unreachable code"));
+  dirFuture.handleException((e) {
     checkDirectoryInNonExistentDirectoryException(e);
     p.toSendPort().send(null);
-  };
+    return true;
+  });
 }
 
 void testReadAsBytesNonExistent() {
   Directory temp = tempDir();
   ReceivePort p = new ReceivePort();
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
   var file = new File("${temp.path}/nonExistentFile3");
 
   // Non-existing file should throw exception.
   Expect.throws(() => file.readAsBytesSync(),
                 (e) => checkOpenNonExistentFileException(e));
 
-  file.readAsBytes((data) => Expect.fail("Unreachable code"));
-  file.onError = (e) {
+  var readAsBytesFuture = file.readAsBytes();
+  readAsBytesFuture.then((data) => Expect.fail("Unreachable code"));
+  readAsBytesFuture.handleException((e) {
     checkOpenNonExistentFileException(e);
     p.toSendPort().send(null);
-  };
+    return true;
+  });
 }
 
 void testReadAsTextNonExistent() {
   Directory temp = tempDir();
   ReceivePort p = new ReceivePort();
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
   var file = new File("${temp.path}/nonExistentFile4");
 
   // Non-existing file should throw exception.
   Expect.throws(() => file.readAsTextSync(),
                 (e) => checkOpenNonExistentFileException(e));
 
-  file.readAsText(Encoding.ASCII, (data) => Expect.fail("Unreachable code"));
-  file.onError = (e) {
+  var readAsTextFuture = file.readAsText(Encoding.ASCII);
+  readAsTextFuture.then((data) => Expect.fail("Unreachable code"));
+  readAsTextFuture.handleException((e) {
     checkOpenNonExistentFileException(e);
     p.toSendPort().send(null);
-  };
+    return true;
+  });
 }
 
 testReadAsLinesNonExistent() {
   Directory temp = tempDir();
   ReceivePort p = new ReceivePort();
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
   var file = new File("${temp.path}/nonExistentFile5");
 
   // Non-existing file should throw exception.
   Expect.throws(() => file.readAsLinesSync(),
                 (e) => checkOpenNonExistentFileException(e));
 
-  file.readAsLines(Encoding.ASCII, (data) => Expect.fail("Unreachable code"));
-  file.onError = (e) {
+  var readAsLinesFuture = file.readAsLines(Encoding.ASCII);
+  readAsLinesFuture.then((data) => Expect.fail("Unreachable code"));
+  readAsLinesFuture.handleException((e) {
     checkOpenNonExistentFileException(e);
     p.toSendPort().send(null);
-  };
+    return true;
+  });
 }
 
 bool checkWriteReadOnlyFileException(e) {
   Expect.isTrue(e is FileIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.osError.errorCode != OSError.noErrorCode);
   return true;
 }
 
 
 // Create a test file in a temporary directory. Setup a port to signal
 // when the temporary directory should be deleted. Pass the file and
 // the port to the callback argument.
 createTestFile(callback) {
   Directory temp = tempDir();
   ReceivePort p = new ReceivePort();
   p.receive((x, y) {
     p.close();
     temp.deleteRecursivelySync();
   });
 
   var file = new File("${temp.path}/test_file");
   file.createSync();
   callback(file, p.toSendPort());
 }
 
 
 testWriteByteToReadOnlyFile() {
   createTestFile((file, port) {
-      var openedFile = file.openSync(FileMode.READ);
+    var openedFile = file.openSync(FileMode.READ);
 
-      // Writing to read only file should throw an exception.
-      Expect.throws(() => openedFile.writeByteSync(0),
-                    (e) => checkWriteReadOnlyFileException(e));
+    // Writing to read only file should throw an exception.
+    Expect.throws(() => openedFile.writeByteSync(0),
+                  (e) => checkWriteReadOnlyFileException(e));
 
-      openedFile.writeByte(0);
-      openedFile.onError = (e) {
-        checkWriteReadOnlyFileException(e);
-        openedFile.close(() => port.send(null));
-    };
+    var writeByteFuture = openedFile.writeByte(0);
+    writeByteFuture.handleException((e) {
+      checkWriteReadOnlyFileException(e);
+      openedFile.close().then((ignore) => port.send(null));
+      return true;
+    });
   });
 }
 
 testWriteListToReadOnlyFile() {
   createTestFile((file, port) {
     var openedFile = file.openSync(FileMode.READ);
 
     List data = [0, 1, 2, 3];
     // Writing to read only file should throw an exception.
     Expect.throws(() => openedFile.writeListSync(data, 0, data.length),
                   (e) => checkWriteReadOnlyFileException(e));
 
-    openedFile.writeList(data, 0, data.length);
-    openedFile.onError = (e) {
+    var writeListFuture = openedFile.writeList(data, 0, data.length);
+    writeListFuture.handleException((e) {
       checkWriteReadOnlyFileException(e);
-      openedFile.close(() => port.send(null));
-    };
+      openedFile.close().then((ignore) => port.send(null));
+      return true;
+    });
   });
 }
 
 testTruncateReadOnlyFile() {
   createTestFile((file, port) {
     var openedFile = file.openSync(FileMode.WRITE);
     openedFile.writeByteSync(0);
     openedFile.closeSync();
     openedFile = file.openSync(FileMode.READ);
 
     // Truncating read only file should throw an exception.
     Expect.throws(() => openedFile.truncateSync(0),
                   (e) => checkWriteReadOnlyFileException(e));
 
-    openedFile.truncate(0, () => Expect.fail("Unreachable code"));
-    openedFile.onError = (e) {
+    var truncateFuture = openedFile.truncate(0);
+    truncateFuture.then((ignore) => Expect.fail("Unreachable code"));
+    truncateFuture.handleException((e) {
       checkWriteReadOnlyFileException(e);
-      openedFile.close(() => port.send(null));
-    };
+      openedFile.close().then((ignore) => port.send(null));
+      return true;
+    });
   });
 }
 
 bool checkFileClosedException(e) {
   Expect.isTrue(e is FileIOException);
   Expect.isTrue(e.toString().indexOf("File closed") != -1);
   Expect.isTrue(e.osError == null);
   return true;
 }
 
@@ skipping 18 matching lines @@
     Expect.throws(() => openedFile.setPositionSync(0),
                   (e) => checkFileClosedException(e));
     Expect.throws(() => openedFile.truncateSync(0),
                   (e) => checkFileClosedException(e));
     Expect.throws(() => openedFile.lengthSync(),
                   (e) => checkFileClosedException(e));
     Expect.throws(() => openedFile.flushSync(),
                   (e) => checkFileClosedException(e));
 
     var errorCount = 0;
-    openedFile.readByte((byte) => Expect.fail("Unreachable code"));
-    errorCount++;
-    openedFile.writeByte(0);
-    errorCount++;
-    openedFile.readList(
-        data, 0, data.length, (bytesRead) => Expect.fail("Unreachable code"));
-    errorCount++;
-    openedFile.writeList(data, 0, data.length);
-    errorCount++;
-    openedFile.writeString("Hello");
-    errorCount++;
-    openedFile.position((position) => Expect.fail("Unreachable code"));
-    errorCount++;
-    openedFile.setPosition(0, () => Expect.fail("Unreachable code"));
-    errorCount++;
-    openedFile.truncate(0, () => Expect.fail("Unreachable code"));
-    errorCount++;
-    openedFile.length((length) => Expect.fail("Unreachable code"));
-    errorCount++;
-    openedFile.flush(() => Expect.fail("Unreachable code"));
-    errorCount++;
 
-    openedFile.onError = (e) {
+    _errorHandler(e) {
       checkFileClosedException(e);
       if (--errorCount == 0) {
         port.send(null);
       }
-    };
+      return true;
+    }
+
+    var readByteFuture = openedFile.readByte();
+    readByteFuture.then((byte) => Expect.fail("Unreachable code"));
+    readByteFuture.handleException(_errorHandler);
+    errorCount++;
+    var writeByteFuture = openedFile.writeByte(0);
+    writeByteFuture.then((ignore) => Expect.fail("Unreachable code"));
+    writeByteFuture.handleException(_errorHandler);
+    errorCount++;
+    var readListFuture = openedFile.readList(data, 0, data.length);
+    readListFuture.then((bytesRead) => Expect.fail("Unreachable code"));
+    readListFuture.handleException(_errorHandler);
+    errorCount++;
+    var writeListFuture = openedFile.writeList(data, 0, data.length);
+    writeListFuture.then((ignore) => Expect.fail("Unreachable code"));
+    writeListFuture.handleException(_errorHandler);
+    errorCount++;
+    var writeStringFuture = openedFile.writeString("Hello");
+    writeStringFuture.then((ignore) => Expect.fail("Unreachable code"));
+    writeStringFuture.handleException(_errorHandler);
+    errorCount++;
+    var positionFuture = openedFile.position();
+    positionFuture.then((position) => Expect.fail("Unreachable code"));
+    positionFuture.handleException(_errorHandler);
+    errorCount++;
+    var setPositionFuture = openedFile.setPosition(0);
+    setPositionFuture.then((ignore) => Expect.fail("Unreachable code"));
+    setPositionFuture.handleException(_errorHandler);
+    errorCount++;
+    var truncateFuture = openedFile.truncate(0);
+    truncateFuture.then((ignore) => Expect.fail("Unreachable code"));
+    truncateFuture.handleException(_errorHandler);
+    errorCount++;
+    var lenFuture = openedFile.length();
+    lenFuture.then((length) => Expect.fail("Unreachable code"));
+    lenFuture.handleException(_errorHandler);
+    errorCount++;
+    var flushFuture = openedFile.flush();
+    flushFuture.then((ignore) => Expect.fail("Unreachable code"));
+    flushFuture.handleException(_errorHandler);
+    errorCount++;
   });
 }
 
 testRepeatedlyCloseFile() {
   createTestFile((file, port) {
     var openedFile = file.openSync();
-    openedFile.close(() {
-      openedFile.onError = (e) {
+    openedFile.close().then((ignore) {
+      var closeFuture = openedFile.close();
+      closeFuture.handleException((e) {
         Expect.isTrue(e is FileIOException);
         port.send(null);
-      };
-      openedFile.close(() => null);
+        return true;
+      });
+      closeFuture.then((ignore) => null);
     });
   });
 }
 
 main() {
   testOpenNonExistent();
   testDeleteNonExistent();
   testLengthNonExistent();
   testCreateInNonExistentDirectory();
   testFullPathOnNonExistentDirectory();
   testDirectoryInNonExistentDirectory();
   testReadAsBytesNonExistent();
   testReadAsTextNonExistent();
   testReadAsLinesNonExistent();
   testWriteByteToReadOnlyFile();
   testWriteListToReadOnlyFile();
   testTruncateReadOnlyFile();
   testOperateOnClosedFile();
   testRepeatedlyCloseFile();
 }