Add base64 decoder and change existing base64 encoder.

tests/lib/crypto/base64_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.
 
 // Library tag to allow the test to run on Dartium.
 library base64_test;
 
 import 'dart:crypto';
+import 'dart:math';
 
 // Data from http://tools.ietf.org/html/rfc4648.
 var inputs =
     const [ '', 'f', 'fo', 'foo', 'foob', 'fooba', 'foobar' ];
 var results =
     const [ '', 'Zg==', 'Zm8=', 'Zm9v', 'Zm9vYg==', 'Zm9vYmE=', 'Zm9vYmFy' ];
 
 var longLine =
     "Man is distinguished, not only by his reason, but by this singular "
     "passion from other animals, which is a lust of the mind, that by a "
@@ skipping 17 matching lines @@
     "x5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0aGlz"
     "IHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlci"
     "BhbmltYWxzLCB3aGljaCBpcyBhIGx1c3Qgb2Yg"
     "dGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcm"
     "FuY2Ugb2YgZGVsaWdodCBpbiB0aGUgY29udGlu"
     "dWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYX"
     "Rpb24gb2Yga25vd2xlZGdlLCBleGNlZWRzIHRo"
     "ZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm"
     "5hbCBwbGVhc3VyZS4=";
 
-void main() {
+void testEncoder() {
   for (var i = 0; i < inputs.length; i++) {
     var enc = CryptoUtils.bytesToBase64(inputs[i].codeUnits);
     Expect.equals(results[i], enc);
   }
-  Expect.equals(CryptoUtils.bytesToBase64(longLine.codeUnits, 76),
+  Expect.equals(CryptoUtils.bytesToBase64(longLine.codeUnits, addLineSeparator : true),

[floitsch, 2013/03/22 17:22:05]

long line.

[mdakin1, 2013/03/25 17:05:02]

Done.

                 longLineResult);
   Expect.equals(CryptoUtils.bytesToBase64(longLine.codeUnits),
                 longLineResultNoBreak);
 }
+
+void testDecoder() {
+  for (var i = 0; i < results.length; i++) {
+    List<int> dec = CryptoUtils.base64StringToBytes(results[i]);
+    Expect.equals(inputs[i], new String.fromCharCodes(dec));
+  }
+  var longLineDecoded = CryptoUtils.base64StringToBytes(longLineResult);
+  Expect.equals(new String.fromCharCodes(longLineDecoded), longLine);
+  var longLineResultNoBreak = CryptoUtils.base64StringToBytes(longLineResult);
+  Expect.equals(new String.fromCharCodes(longLineResultNoBreak), longLine);
+}
+
+void testDecoderForMalformedInput() {
+  try {
+    CryptoUtils.base64StringToBytes("AB~", ignoreErrors : false);

[floitsch, 2013/03/22 17:22:05]

We usually use:
Expect.throws(() { CryptoUtils.base64StringToBytes("AB~", ignoreErrors: false);
},
              (e) => e is FormatException);

Note: no space before the ":" of named arguments.

[mdakin1, 2013/03/25 17:05:02]

Done.

+    Expect.fail("Should have failed on Malformed input.");
+  } on FormatException catch(e) {
+    // pass
+  }
+  try {
+    // Missing padding.
+    CryptoUtils.base64StringToBytes("Zg=", ignoreErrors : false);
+    Expect.fail("Should have failed on Malformed input.");
+  } on FormatException catch(e) {
+    // pass
+  }
+}
+
+void testUrlSafeEncodeDecode() {
+    CryptoUtils.base64StringToBytes("AB~", ignoreErrors : false);
+    CryptoUtils.base64StringToBytes("Zg=", ignoreErrors : false);
+}
+
+void testEncodeDecodeLists() {
+  for (int i = 0; i < 10; i++) {
+    for (int j = 0; j < 256 - i; j++) {
+      List<int> x = new List<int>(i);
+      for (int k = 0; k < i; k++) {
+        x[k] = j;
+      }
+      var enc = CryptoUtils.bytesToBase64(x);
+      var dec = CryptoUtils.base64StringToBytes(enc);
+      Expect.listEquals(x, dec);
+    }
+  }
+}
+
+fillRandom(List<int> l) {
+  var random = new Random(0xBABE);
+  for(int j=0; j < l.length; j++) {
+    l[j] = random.nextInt(255);
+  }
+}
+void testPerformance() {
+    var l = new List<int>(1024);
+    var iters = 50000;
+    fillRandom(l);
+    String enc;
+    var w = new Stopwatch()..start();
+    for( int i = 0; i < iters; ++i ) {
+      enc = CryptoUtils.bytesToBase64(l);
+    }
+    int ms = w.elapsedMilliseconds;
+    int perSec = (iters * l.length) * 1000 ~/ ms;
+    print("Encode 1024 bytes for $iters times: $ms msec. $perSec b/s");

[floitsch, 2013/03/22 17:22:05]

Don't print in tests. But you can leave it behind comments.

[mdakin1, 2013/03/25 17:05:02]

Uh, this was meant to be removed before uploading. but I guess keeping the test
here doesn't hurt. It's not slow. Commented out print.

+    w..reset();
+    for( int i = 0; i < iters; ++i ) {
+      CryptoUtils.base64StringToBytes(enc);
+    }
+    ms = w.elapsedMilliseconds;
+    perSec = (iters * l.length) * 1000 ~/ ms;
+    print("Decode into ${l.length} bytes for $iters times: $ms msec. $perSec b/s");

[floitsch, 2013/03/22 17:22:05]

80 chars.

[mdakin1, 2013/03/25 17:05:02]

Done.

+}
+
+void main() {
+  testEncoder();
+  testDecoder();
+  testDecoderForMalformedInput();
+  testEncodeDecodeLists();
+//  testUrlSafeEncodeDecode();
+  testPerformance();
+}