Revert "Rename blahHandler to onBlah throughout dart:io."

tests/standalone/src/FileTest.dart

Index: tests/standalone/src/FileTest.dart
diff --git a/tests/standalone/src/FileTest.dart b/tests/standalone/src/FileTest.dart
index 58a9a7b5f08fd83808c11f5dfaf3250403378eb7..f2ca38d7b2fd52092d1f997b69eeff070d422cbe 100644
--- a/tests/standalone/src/FileTest.dart
+++ b/tests/standalone/src/FileTest.dart
@@ -28,14 +28,15 @@ class FileTest {
 
   static void createTempDirectory(Function doNext) {
     tempDirectory = new Directory('');
-    tempDirectory.onError = (e) {
+    tempDirectory.errorHandler = (e) {
       Expect.fail("Failed creating temporary directory");
     };
-    tempDirectory.createTemp(doNext);
+    tempDirectory.createTempHandler = doNext;
+    tempDirectory.createTemp();
   }
 
   static void deleteTempDirectory() {
-    tempDirectory.deleteRecursivelySync();
+    tempDirectory.deleteSync(recursive: true);
   }
 
   // Test for file read functionality.
@@ -44,7 +45,7 @@ class FileTest {
     String filename = getFilename("bin/file_test.cc");
     File file = new File(filename);
     InputStream input = file.openInputStream();
-    input.onData = () {
+    input.dataHandler = () {
       List<int> buffer = new List<int>(42);
       int bytesRead = input.readInto(buffer, 0, 12);
       Expect.equals(12, bytesRead);
@@ -79,7 +80,7 @@ class FileTest {
     // Test reading all using readInto.
     file = new File(inFilename);
     input = file.openInputStream();
-    input.onData = () {
+    input.dataHandler = () {
       List<int> buffer1 = new List<int>(42);
       bytesRead = input.readInto(buffer1, 0, 42);
       Expect.equals(42, bytesRead);
@@ -88,7 +89,7 @@ class FileTest {
       // Test reading all using readInto and read.
       file = new File(inFilename);
       input = file.openInputStream();
-      input.onData = () {
+      input.dataHandler = () {
         bytesRead = input.readInto(buffer1, 0, 21);
         Expect.equals(21, bytesRead);
         buffer1 = input.read();
@@ -98,7 +99,7 @@ class FileTest {
         // Test reading all using read and readInto.
         file = new File(inFilename);
         input = file.openInputStream();
-        input.onData = () {
+        input.dataHandler = () {
           buffer1 = input.read(21);
           Expect.equals(21, buffer1.length);
           bytesRead = input.readInto(buffer1, 0, 21);
@@ -108,7 +109,7 @@ class FileTest {
           // Test reading all using read.
           file = new File(inFilename);
           input = file.openInputStream();
-          input.onData = () {
+          input.dataHandler = () {
             buffer1 = input.read();
             Expect.equals(42, buffer1.length);
             Expect.isTrue(input.closed);
@@ -119,14 +120,14 @@ class FileTest {
             OutputStream output = file.openOutputStream();
             bool writeDone = output.writeFrom(buffer1, 0, 42);
             Expect.equals(false, writeDone);
-            output.onNoPendingWrites = () {
+            output.noPendingWriteHandler = () {
               output.close();
-              output.onClosed = () {
+              output.closeHandler = () {
                 // Now read the contents of the file just written.
                 List<int> buffer2 = new List<int>(42);
                 file = new File(outFilename);
                 input = file.openInputStream();
-                input.onData = () {
+                input.dataHandler = () {
                   bytesRead = input.readInto(buffer2, 0, 42);
                   Expect.equals(42, bytesRead);
                   // Now compare the two buffers to check if they are identical.
@@ -134,7 +135,7 @@ class FileTest {
                     Expect.equals(buffer1[i],  buffer2[i]);
                   }
                 };
-                input.onClosed = () {
+                input.closeHandler = () {
                   // Delete the output file.
                   file.deleteSync();
                   Expect.isFalse(file.existsSync());
@@ -152,14 +153,14 @@ class FileTest {
     // Read a file and check part of it's contents.
     String filename = getFilename("bin/file_test.cc");
     File file = new File(filename);
-    file.onError = (s) {
+    file.errorHandler = (s) {
       Expect.fail("No errors expected : $s");
     };
-    file.open(FileMode.READ, (RandomAccessFile file) {
+    file.openHandler = (RandomAccessFile file) {
       List<int> buffer = new List<int>(10);
-      file.readList(buffer, 0, 5, (bytes_read) {
+      file.readListHandler = (bytes_read) {
         Expect.equals(5, bytes_read);
-        file.readList(buffer, 5, 5, (bytes_read) {
+        file.readListHandler = (bytes_read) {
           Expect.equals(5, bytes_read);
           Expect.equals(47, buffer[0]);  // represents '/' in the file.
           Expect.equals(47, buffer[1]);  // represents '/' in the file.
@@ -171,10 +172,13 @@ class FileTest {
           Expect.equals(114, buffer[7]);  // represents 'r' in the file.
           Expect.equals(105, buffer[8]);  // represents 'i' in the file.
           Expect.equals(103, buffer[9]);  // represents 'g' in the file.
-          file.close(() => null);
-        });
-      });
-    });
+          file.close();
+        };
+        file.readList(buffer, 5, 5);
+      };
+      file.readList(buffer, 0, 5);
+    };
+    file.open();
   }
 
   static void testReadSync() {
@@ -206,48 +210,47 @@ class FileTest {
     // Read a file.
     String inFilename = getFilename("tests/vm/data/fixed_length_file");
     final File file = new File(inFilename);
-    file.onError = (s) {
+    file.errorHandler = (s) {
       Expect.fail("No errors expected : $s");
     };
-    file.open(FileMode.READ, (RandomAccessFile openedFile) {
-      openedFile.onError = (s) {
+    file.openHandler = (RandomAccessFile openedFile) {
+      openedFile.errorHandler = (s) {
         Expect.fail("No errors expected : $s");
       };
       List<int> buffer1 = new List<int>(42);
-      openedFile.readList(buffer1, 0, 42, (bytes_read) {
+      openedFile.readListHandler = (bytes_read) {
         Expect.equals(42, bytes_read);
-        openedFile.close(() {
+        openedFile.closeHandler = () {
           // Write the contents of the file just read into another file.
           String outFilename = tempDirectory.path + "/out_read_write";
           final File file2 = new File(outFilename);
-          file2.onError = (s) {
+          file2.errorHandler = (s) {
             Expect.fail("No errors expected : $s");
           };
-          file2.create(() {
-            file2.fullPath((s) {
+          file2.createHandler = () {
+            file2.fullPathHandler = (s) {
               Expect.isTrue(new File(s).existsSync());
               if (s[0] != '/' && s[0] != '\\' && s[1] != ':') {
                 Expect.fail("Not a full path");
               }
-              file2.open(FileMode.WRITE, (RandomAccessFile openedFile2) {
-                openedFile2.onError = (s) {
+              file2.openHandler = (RandomAccessFile openedFile2) {
+                openedFile2.errorHandler = (s) {
                   Expect.fail("No errors expected : $s");
                 };
-                openedFile2.writeList(buffer1, 0, bytes_read);
-                openedFile2.onNoPendingWrites = () {
-                  openedFile2.close(() {
+                openedFile2.noPendingWriteHandler = () {
+                  openedFile2.closeHandler = () {
                     List<int> buffer2 = new List<int>(bytes_read);
                     final File file3 = new File(outFilename);
-                    file3.onError = (s) {
+                    file3.errorHandler = (s) {
                       Expect.fail("No errors expected : $s");
                     };
-                    file3.open(FileMode.READ, (RandomAccessFile openedFile3) {
-                      openedFile3.onError = (s) {
+                    file3.openHandler = (RandomAccessFile openedFile3) {
+                      openedFile3.errorHandler = (s) {
                         Expect.fail("No errors expected : $s");
                       };
-                      openedFile3.readList(buffer2, 0, 42, (bytes_read) {
+                      openedFile3.readListHandler = (bytes_read) {
                        Expect.equals(42, bytes_read);
-                        openedFile3.close(() {
+                        openedFile3.closeHandler = () {
                           // Now compare the two buffers to check if they
                           // are identical.
                           Expect.equals(buffer1.length, buffer2.length);
@@ -256,24 +259,37 @@ class FileTest {
                           }
                           // Delete the output file.
                           final file4 = file3;
-                          file4.delete(() {
-                            file4.exists((exists) {
+                          file4.deleteHandler = () {
+                            file4.existsHandler = (exists) {
                               Expect.isFalse(exists);
                               asyncTestDone("testReadWrite");
-                            });
-                          });
-                        });
-                      });
-                    });
-                  });
+                            };
+                            file4.exists();
+                          };
+                          file4.delete();
+                        };
+                        openedFile3.close();
+                      };
+                      openedFile3.readList(buffer2, 0, 42);
+                    };
+                    file3.open();
+                  };
+                  openedFile2.close();
                 };
-              });
-            });
-          });
-        });
-      });
-    });
+                openedFile2.writeList(buffer1, 0, bytes_read);
+              };
+              file2.open(FileMode.WRITE);
+            };
+            file2.fullPath();
+          };
+          file2.create();
+        };
+        openedFile.close();
+      };
+      openedFile.readList(buffer1, 0, 42);
+    };
     asyncTestStarted();
+    file.open();
   }
 
   static void testWriteAppend() {
@@ -308,25 +324,29 @@ class FileTest {
     List<int> buffer = content.charCodes();
     OutputStream outStream = file.openOutputStream();
     outStream.write(buffer);
-    outStream.onNoPendingWrites = () {
+    outStream.noPendingWriteHandler = () {
       outStream.close();
       File file2 = new File(filename);
       OutputStream appendingOutput =
           file2.openOutputStream(FileMode.APPEND);
       appendingOutput.write(buffer);
-      appendingOutput.onNoPendingWrites = () {
+      appendingOutput.noPendingWriteHandler = () {
         appendingOutput.close();
         File file3 = new File(filename);
-        file3.open(FileMode.READ, (RandomAccessFile openedFile) {
-          openedFile.length((int length) {
+        file3.openHandler = (RandomAccessFile openedFile) {
+          openedFile.lengthHandler = (int length) {
             Expect.equals(content.length * 2, length);
-            openedFile.close(() {
-              file3.delete(() {
+            openedFile.closeHandler = () {
+              file3.deleteHandler = () {
                 asyncTestDone("testOutputStreamWriteAppend");
-              });
-            });
-          });
-        });
+              };
+              file3.delete();
+            };
+            openedFile.close();
+          };
+          openedFile.length();
+        };
+        file3.open();
       };
     };
     asyncTestStarted();
@@ -384,25 +404,30 @@ class FileTest {
   static void testReadEmptyFile() {
     String fileName = tempDirectory.path + "/empty_file";
     File file = new File(fileName);
-    file.onError = (s) {
+    file.errorHandler = (s) {
       Expect.fail("No errors expected : $s");
     };
-    asyncTestStarted();
-    file.create(() {
-      file.open(FileMode.READ, (RandomAccessFile openedFile) {
-        openedFile.readByte((int byte) {
+    file.createHandler = () {
+      file.openHandler = (RandomAccessFile openedFile) {
+        openedFile.readByteHandler = (int byte) {
           Expect.fail("Read byte from empty file");
-        });
-        openedFile.onError = (String err) {
+        };
+        openedFile.errorHandler = (String err) {
           Expect.isTrue(err.indexOf("failed") != -1);
-          openedFile.close(() {
-            file.delete(() {
+          openedFile.closeHandler = () {
+            file.deleteHandler = () {
               asyncTestDone("testReadEmptyFile");
-            });
-          });
+            };
+            file.delete();
+          };
+          openedFile.close();
         };
-      });
-    });
+        openedFile.readByte();
+      };
+      file.open();
+    };
+    asyncTestStarted();
+    file.create();
   }
 
   // Test for file write of different types of lists.
@@ -410,11 +435,10 @@ class FileTest {
     asyncTestStarted();
     final String fileName = "${tempDirectory.path}/testWriteVariousLists";
     final File file = new File(fileName);
-    file.onError = (s) {
-      Expect.fail("No errors expected : $s");
-    };
-    file.create(() {
-      file.open(FileMode.WRITE, (RandomAccessFile openedFile) {
+    file.create();
+    file.createHandler = () {
+      file.open(FileMode.WRITE);
+      file.openHandler = (RandomAccessFile openedFile) {
         // Write bytes from 0 to 7.
         openedFile.writeList([0], 0, 1);
         openedFile.writeList(const [1], 0, 1);
@@ -429,28 +453,32 @@ class FileTest {
         y = 12345678901234567890123456789012345678901234568153;
         openedFile.writeList([y - x], 0, 1);
 
-        openedFile.onError = (s) {
+        openedFile.errorHandler = (s) {
           Expect.fail("No errors expected : $s");
         };
-        openedFile.onNoPendingWrites = () {
-          openedFile.close(() {
-            // Check the written bytes.
-            final File file2 = new File(fileName);
-            var openedFile2 = file2.openSync();
-            var length = openedFile2.lengthSync();
-            Expect.equals(8, length);
-            List data = new List(length);
-            openedFile2.readListSync(data, 0, length);
-            for (var i = 0; i < data.length; i++) {
-              Expect.equals(i, data[i]);
-            }
-            openedFile2.closeSync();
-            file2.deleteSync();
-            asyncTestDone("testWriteVariousLists");
-          });
+        openedFile.noPendingWriteHandler = () {
+          openedFile.close();
         };
-      });
-    });
+        openedFile.closeHandler = () {
+          // Check the written bytes.
+          final File file2 = new File(fileName);
+          var openedFile2 = file2.openSync();
+          var length = openedFile2.lengthSync();
+          Expect.equals(8, length);
+          List data = new List(length);
+          openedFile2.readListSync(data, 0, length);
+          for (var i = 0; i < data.length; i++) {
+            Expect.equals(i, data[i]);
+          }
+          openedFile2.closeSync();
+          file2.deleteSync();
+          asyncTestDone("testWriteVariousLists");
+        };
+      };
+      file.errorHandler = (s) {
+        Expect.fail("No errors expected : $s");
+      };
+    };
   }
 
   static void testDirectory() {
@@ -466,29 +494,40 @@ class FileTest {
     var tempDir = tempDirectory.path;
     var file = new File("${tempDir}/testDirectory");
     var errors = 0;
-    file.directory((d) => Expect.fail("non-existing file"));
-    file.onError = (s) {
-      file.onError = (s) => Expect.fail("no error expected");
-      file.create(() {
-        file.directory((Directory d) {
-          d.onError = (s) => Expect.fail("no error expected");
-          d.exists((exists) {
+    file.directory();
+    file.directoryHandler = (d) => Expect.fail("non-existing file");
+    file.errorHandler = (s) {
+      file.errorHandler = (s) => Expect.fail("no error expected");
+      file.create();
+      file.createHandler = () {
+        file.directory();
+        file.directoryHandler = (Directory d) {
+          d.exists();
+          d.errorHandler = (s) => Expect.fail("no error expected");
+          d.existsHandler = (exists) {
             Expect.isTrue(exists);
             Expect.isTrue(d.path.endsWith(tempDir));
-            file.delete(() {
+            file.delete();
+            file.deleteHandler = () {
               var file_dir = new File(".");
-              file_dir.directory((d) => Expect.fail("non-existing file"));
-              file_dir.onError = (s) {
+              file_dir.directory();
+              file_dir.directoryHandler = (d) {
+                Expect.fail("non-existing file");
+              };
+              file_dir.errorHandler = (s) {
                 var file_dir = new File(tempDir);
-                file_dir.directory((d) => Expect.fail("non-existing file"));
-                file_dir.onError = (s) {
+                file_dir.directory();
+                file_dir.directoryHandler = (d) {
+                  Expect.fail("non-existing file");
+                };
+                file_dir.errorHandler = (s) {
                   port.toSendPort().send(1);
                 };
               };
-            });
-          });
-        });
-      });
+            };
+          };
+        };
+      };
     };
   }
 
@@ -514,13 +553,14 @@ class FileTest {
   static void testLength() {
     String filename = getFilename("tests/vm/data/fixed_length_file");
     RandomAccessFile input = (new File(filename)).openSync();
-    input.onError = (s) {
+    input.errorHandler = (s) {
       Expect.fail("No errors expected");
     };
-    input.length((length) {
+    input.lengthHandler = (length) {
       Expect.equals(42, length);
-      input.close(() => null);
-    });
+      input.close();
+    };
+    input.length();
   }
 
   static void testLengthSync() {
@@ -534,29 +574,35 @@ class FileTest {
   static void testPosition() {
     String filename = getFilename("tests/vm/data/fixed_length_file");
     RandomAccessFile input = (new File(filename)).openSync();
-    input.onError = (s) {
+    input.errorHandler = (s) {
       Expect.fail("No errors expected");
     };
-    input.position((position) {
+    input.positionHandler = (position) {
       Expect.equals(0, position);
       List<int> buffer = new List<int>(100);
-      input.readList(buffer, 0, 12, (bytes_read) {
-        input.position((position) {
+      input.readListHandler = (bytes_read) {
+        input.positionHandler = (position) {
           Expect.equals(12, position);
-          input.readList(buffer, 12, 6, (bytes_read) {
-            input.position((position) {
+          input.readListHandler = (bytes_read) {
+            input.positionHandler = (position) {
               Expect.equals(18, position);
-              input.setPosition(8, () {
-                input.position((position) {
+              input.setPositionHandler = () {
+                input.positionHandler = (position) {
                   Expect.equals(8, position);
-                  input.close(() => null);
-                });
-              });
-            });
-          });
-        });
-      });
-    });
+                  input.close();
+                };
+                input.position();
+              };
+              input.setPosition(8);
+            };
+          };
+          input.readList(buffer, 12, 6);
+        };
+        input.position();
+      };
+      input.readList(buffer, 0, 12);
+    };
+    input.position();
   }
 
   static void testPositionSync() {
@@ -576,31 +622,38 @@ class FileTest {
   static void testTruncate() {
     File file = new File(tempDirectory.path + "/out_truncate");
     List buffer = const [65, 65, 65, 65, 65, 65, 65, 65, 65, 65];
-    file.onError = (error) {
+    file.errorHandler = (error) {
       Expect.fail("testTruncate: No errors expected");
     };
-    file.open(FileMode.WRITE, (RandomAccessFile openedFile) {
-      openedFile.writeList(buffer, 0, 10);
-      openedFile.onNoPendingWrites = () {
-        openedFile.length((length) {
+    file.openHandler = (RandomAccessFile openedFile) {
+      openedFile.noPendingWriteHandler = () {
+        openedFile.lengthHandler = (length) {
           Expect.equals(10, length);
-          openedFile.truncate(5, () {
-            openedFile.length((length) {
+          openedFile.truncateHandler = () {
+            openedFile.lengthHandler = (length) {
               Expect.equals(5, length);
-              openedFile.close(() {
-                file.delete(() {
-                  file.exists((exists) {
+              openedFile.closeHandler = () {
+                file.deleteHandler = () {
+                  file.existsHandler = (exists) {
                     Expect.isFalse(exists);
                     asyncTestDone("testTruncate");
-                  });
-                });
-              });
-            });
-          });
-        });
+                  };
+                  file.exists();
+                };
+                file.delete();
+              };
+              openedFile.close();
+            };
+            openedFile.length();
+          };
+          openedFile.truncate(5);
+        };
+        openedFile.length();
       };
-    });
+      openedFile.writeList(buffer, 0, 10);
+    };
     asyncTestStarted();
+    file.open(FileMode.WRITE);
   }
 
   static void testTruncateSync() {
@@ -714,13 +767,13 @@ class FileTest {
     File file = new File(tempDirectory.path + "/out_close_exception_stream");
     file.createSync();
     InputStream input = file.openInputStream();
-    input.onClosed = () {
+    input.closeHandler = () {
       Expect.isTrue(input.closed);
       Expect.isNull(input.readInto(buffer, 0, 12));
       OutputStream output = file.openOutputStream();
       output.close();
       Expect.throws(() => output.writeFrom(buffer, 0, 12));
-      output.onClosed = () {
+      output.closeHandler = () {
         file.deleteSync();
         asyncTestDone("testCloseExceptionStream");
       };
@@ -827,22 +880,24 @@ class FileTest {
   static void testMixedSyncAndAsync() {
     var name = getFilename("tests/vm/data/fixed_length_file");
     var f = new File(name);
-    f.onError = (s) {
+    f.errorHandler = (s) {
       Expect.fail("No errors expected");
     };
-    f.exists((exists) {
+    f.existsHandler = (exists) {
       try {
         f.existsSync();
         Expect.fail("Expected exception");
       } catch (var e) {
         Expect.isTrue(e is FileIOException);
       }
-    });
+    };
+    f.exists();
   }
 
   static void testOpenDirectoryAsFile() {
     var f = new File('.');
-    f.open(FileMode.READ, (r) => Expect.fail('Directory opened as file'));
+    f.open();
+    f.openHandler = (r) => Expect.fail('Directory opened as file');
   }
 
   static void testOpenDirectoryAsFileSync() {
@@ -862,11 +917,12 @@ class FileTest {
     });
     var name = getFilename("tests/vm/data/fixed_length_file");
     var f = new File(name);
-    f.readAsBytes((bytes) {
+    f.readAsBytes();
+    f.readAsBytesHandler = (bytes) {
       Expect.isTrue(new String.fromCharCodes(bytes).endsWith("42 bytes."));
       port.toSendPort().send(bytes.length);
-    });
-    f.onError = (e) {
+    };
+    f.errorHandler = (e) {
       Expect.fail("No errors expected: $e");
     };
   }
@@ -885,30 +941,34 @@ class FileTest {
     });
     var name = getFilename("tests/vm/data/fixed_length_file");
     var f = new File(name);
-    f.readAsText('UTF-8', (text) {
+    f.readAsText('UTF-8');
+    f.readAsTextHandler = (text) {
       Expect.isTrue(text.endsWith("42 bytes."));
       Expect.equals(42, text.length);
       var name = getDataFilename("tests/standalone/src/read_as_text.dat");
       var f = new File(name);
-      f.onError = (e) => Expect.fail("No errors expected");
-      f.readAsText('UTF-8', (text) {
+      f.errorHandler = (e) => Expect.fail("No errors expected");
+      f.readAsText('UTF-8');
+      f.readAsTextHandler = (text) {
         Expect.equals(6, text.length);
         var expected = [955, 120, 46, 32, 120, 10];
         Expect.listEquals(expected, text.charCodes());
-        f.readAsText('ISO-8859-1', (text) {
+        f.readAsText('ISO-8859-1');
+        f.readAsTextHandler = (text) {
           Expect.equals(7, text.length);
           var expected = [206, 187, 120, 46, 32, 120, 10];
           Expect.listEquals(expected, text.charCodes());
-          f.onError = (e) {
+          f.readAsText('ASCII');
+          f.errorHandler = (e) {
             port.toSendPort().send(1);
           };
-          f.readAsText('ASCII', (text) {
+          f.readAsTextHandler = (text) {
             Expect.fail("Non-ascii char should cause error");
-          });
-        });
-      });
-    });
-    f.onError = (e) {
+          };
+        };
+      };
+    };
+    f.errorHandler = (e) {
       Expect.fail("No errors expected: $e");
     };
   }
@@ -937,13 +997,14 @@ class FileTest {
     });
     var name = getFilename("tests/vm/data/fixed_length_file");
     var f = new File(name);
-    f.readAsLines('UTF-8', (lines) {
+    f.readAsLines('UTF-8');
+    f.readAsLinesHandler = (lines) {
       Expect.equals(1, lines.length);
       var line = lines[0];
       Expect.isTrue(line.endsWith("42 bytes."));
       port.toSendPort().send(line.length);
-    });
-    f.onError = (e) {
+    };
+    f.errorHandler = (e) {
       Expect.fail("No errors expected: $e");
     };
   }
@@ -970,12 +1031,12 @@ class FileTest {
     Expect.throws(f.readAsBytesSync, (e) => e is FileIOException);
     Expect.throws(f.readAsTextSync, (e) => e is FileIOException);
     Expect.throws(f.readAsLinesSync, (e) => e is FileIOException);
-    f.readAsBytes((bytes) => Expect.fail("no bytes expected"));
-    f.onError = (e) {
-      f.readAsText('UTF-8', (text) => Expect.fail("no text expected"));
-      f.onError = (e) {
-        f.readAsLines('UTF-8', (lines) => Expect.fail("no lines expected"));
-        f.onError = (e) {
+    f.readAsBytes();
+    f.errorHandler = (e) {
+      f.readAsText();
+      f.errorHandler = (e) {
+        f.readAsLines();
+        f.errorHandler = (e) {
           port.toSendPort().send(1);
         };
       };
@@ -986,33 +1047,44 @@ class FileTest {
   // that the file is not truncated when opened for appending.
   static void testAppend() {
     var file = new File('${tempDirectory.path}/out_append');
-    file.open(FileMode.WRITE, (openedFile) {
-      openedFile.writeString("asdf");
-      openedFile.onNoPendingWrites = () {
-        openedFile.close(() {
-          file.open(FileMode.APPEND, (openedFile) {
-            openedFile.length((length) {
+    file.openHandler = (openedFile) {
+      openedFile.noPendingWriteHandler = () {
+        openedFile.closeHandler = () {
+          file.openHandler = (openedFile) {
+            openedFile.lengthHandler = (length) {
               Expect.equals(4, length);
-              openedFile.writeString("asdf");
-              openedFile.onNoPendingWrites = () {
-                openedFile.length((length) {
-                  Expect.equals(8, length);
-                  openedFile.close(() {
-                    file.delete(() {
-                      file.exists((exists) {
-                        Expect.isFalse(exists);
-                        asyncTestDone("testAppend");
-                      });
-                    });
-                  });
-                });
+              openedFile.setPositionHandler = () {
+                openedFile.noPendingWriteHandler = () {
+                  openedFile.lengthHandler = (length) {
+                    Expect.equals(8, length);
+                    openedFile.closeHandler = () {
+                      file.deleteHandler = () {
+                        file.existsHandler = (exists) {
+                          Expect.isFalse(exists);
+                          asyncTestDone("testAppend");
+                        };
+                        file.exists();
+                      };
+                      file.delete();
+                    };
+                    openedFile.close();
+                  };
+                  openedFile.length();
+                };
+                openedFile.writeString("asdf");
               };
-            });
-          });
-        });
+              openedFile.setPosition(4);
+            };
+            openedFile.length();
+          };
+          file.open(FileMode.APPEND);
+        };
+        openedFile.close();
       };
-    });
+      openedFile.writeString("asdf");
+    };
     asyncTestStarted();
+    file.open(FileMode.WRITE);
   }
 
   static void testAppendSync() {