Remove Encoding-enum from dart:io and add interface in dart:convert.

tests/standalone/io/file_test.dart

 // Copyright (c) 2013, 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 file I/O.
 
 import "package:expect/expect.dart";
 import "package:path/path.dart";
 import 'dart:async';
+import 'dart:convert';
 import 'dart:collection';
 import 'dart:io';
 import 'dart:isolate';
 
 class MyListOfOneElement
     extends Object with ListMixin<int> implements List<int> {
   int _value;
   MyListOfOneElement(this._value);
   int get length => 1;
   operator [](int index) => _value;
@@ skipping 366 matching lines @@
 
   // Test for file read and write functionality.
   static void testOutputStreamWriteString() {
     String content = "foobar";
     String filename = tempDirectory.path + "/outstream_write_string";
     File file = new File(filename);
     file.createSync();
     List<int> buffer = content.codeUnits;
     var output = file.openWrite();
     output.write("abcdABCD");
-    output.encoding = UTF_8;
+    output.encoding = UTF8;
     output.write("abcdABCD");
-    output.encoding = ISO_8859_1;
+    output.encoding = LATIN1;
     output.write("abcdABCD");
     output.encoding = ASCII;
     output.write("abcdABCD");
-    output.encoding = UTF_8;
+    output.encoding = UTF8;
     output.write("æøå");
     output.close();
     output.done.then((_) {
       RandomAccessFile raf = file.openSync();
       Expect.equals(38, raf.lengthSync());
       raf.close().then((ignore) {
         asyncTestDone("testOutputStreamWriteString");
       });
     });
     asyncTestStarted();
@@ skipping 565 matching lines @@
   }
 
   static void testReadAsText() {
     var port = new ReceivePort();
     port.receive((result, replyTo) {
       port.close();
       Expect.equals(1, result);
     });
     var name = getFilename("tests/vm/data/fixed_length_file");
     var f = new File(name);
-    f.readAsString(encoding: UTF_8).then((text) {
+    f.readAsString(encoding: UTF8).then((text) {
       Expect.isTrue(text.endsWith("42 bytes."));
       Expect.equals(42, text.length);
       var name = getDataFilename("tests/standalone/io/read_as_text.dat");
       var f = new File(name);
-      f.readAsString(encoding: UTF_8).then((text) {
+      f.readAsString(encoding: UTF8).then((text) {
         Expect.equals(6, text.length);
         var expected = [955, 120, 46, 32, 120, 10];
         Expect.listEquals(expected, text.codeUnits);
-        f.readAsString(encoding: ISO_8859_1).then((text) {
+        f.readAsString(encoding: LATIN1).then((text) {
           Expect.equals(7, text.length);
           var expected = [206, 187, 120, 46, 32, 120, 10];
           Expect.listEquals(expected, text.codeUnits);
           var readAsStringFuture = f.readAsString(encoding: ASCII);
           readAsStringFuture.then((text) {
             Expect.fail("Non-ascii char should cause error");
           }).catchError((e) {
             port.toSendPort().send(1);
           });
         });
       });
     });
   }
 
   static void testReadAsTextEmptyFile() {
     var port = new ReceivePort();
     port.receive((result, replyTo) {
       port.close();
       Expect.equals(0, result);
     });
     var name = getFilename("tests/vm/data/empty_file");
     var f = new File(name);
-    f.readAsString(encoding: UTF_8).then((text) {
+    f.readAsString(encoding: UTF8).then((text) {
       port.toSendPort().send(text.length);
       return true;
     });
   }
 
   static void testReadAsTextSync() {
     var name = getFilename("tests/vm/data/fixed_length_file");
     var text = new File(name).readAsStringSync();
     Expect.isTrue(text.endsWith("42 bytes."));
     Expect.equals(42, text.length);
     name = getDataFilename("tests/standalone/io/read_as_text.dat");
     text = new File(name).readAsStringSync();
     Expect.equals(6, text.length);
     var expected = [955, 120, 46, 32, 120, 10];
     Expect.listEquals(expected, text.codeUnits);
-    text = new File(name).readAsStringSync(encoding: ASCII);
-    // Default replacement character is '?', char code 63.
-    expected = [63, 63, 120, 46, 32, 120, 10];
+    // First character is not ASCII. The default ASCII decoder will throw.
+    Expect.throws(() => new File(name).readAsStringSync(encoding: ASCII),
+                  (e) => e is FormatError);
+    // We can use an ASCII decoder that inserts the replacement character.
+    var lenientAscii = const AsciiCodec(allowInvalid: true);
+    text = new File(name).readAsStringSync(encoding: lenientAscii);
+    // Default replacement character is the Unicode replacement character.
+    expected = [UNICODE_REPLACEMENT_CHARACTER_RUNE,
+                UNICODE_REPLACEMENT_CHARACTER_RUNE,
+                120, 46, 32, 120, 10];
     Expect.listEquals(expected, text.codeUnits);
-    text = new File(name).readAsStringSync(encoding: ISO_8859_1);
+    text = new File(name).readAsStringSync(encoding: LATIN1);
     expected = [206, 187, 120, 46, 32, 120, 10];
     Expect.equals(7, text.length);
     Expect.listEquals(expected, text.codeUnits);
   }
 
   static void testReadAsTextSyncEmptyFile() {
     var name = getFilename("tests/vm/data/empty_file");
     var text = new File(name).readAsStringSync();
     Expect.equals(0, text.length);
   }
 
   static void testReadAsLines() {
     var port = new ReceivePort();
     port.receive((result, replyTo) {
       port.close();
       Expect.equals(42, result);
     });
     var name = getFilename("tests/vm/data/fixed_length_file");
     var f = new File(name);
-    f.readAsLines(encoding: UTF_8).then((lines) {
+    f.readAsLines(encoding: UTF8).then((lines) {
       Expect.equals(1, lines.length);
       var line = lines[0];
       Expect.isTrue(line.endsWith("42 bytes."));
       port.toSendPort().send(line.length);
     });
   }
 
   static void testReadAsLinesSync() {
     var name = getFilename("tests/vm/data/fixed_length_file");
     var lines = new File(name).readAsLinesSync();
@@ skipping 13 matching lines @@
       port.close();
       Expect.equals(1, message);
     });
     var f = new File('.');
     Expect.throws(f.readAsBytesSync, (e) => e is FileException);
     Expect.throws(f.readAsStringSync, (e) => e is FileException);
     Expect.throws(f.readAsLinesSync, (e) => e is FileException);
     var readAsBytesFuture = f.readAsBytes();
     readAsBytesFuture.then((bytes) => Expect.fail("no bytes expected"))
     .catchError((e) {
-      var readAsStringFuture = f.readAsString(encoding: UTF_8);
+      var readAsStringFuture = f.readAsString(encoding: UTF8);
       readAsStringFuture.then((text) => Expect.fail("no text expected"))
       .catchError((e) {
-        var readAsLinesFuture = f.readAsLines(encoding: UTF_8);
+        var readAsLinesFuture = f.readAsLines(encoding: UTF8);
         readAsLinesFuture.then((lines) => Expect.fail("no lines expected"))
         .catchError((e) {
           port.toSendPort().send(1);
         });
       });
     });
   }
 
   static void testLastModified() {
     var port = new ReceivePort();
@@ skipping 222 matching lines @@
       testWriteStringUtf8Sync();
       testRename();
       testRenameSync();
     });
   }
 }
 
 main() {
   FileTest.testMain();
 }