Fix coded buffer reader so all tests pass using dart2js.

Bug: #59 BUG= R=sgjesse@google.com Review URL: https://codereview.chromium.org//2094533003 .
google · Jun 27, 2016 · 6ab6e52 · 6ab6e52
1 parent f7ee81e
commit 6ab6e52
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Showing 3 changed files with 37 additions and 30 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## upcoming
+
+* fix zigzag function so all coded buffer reader tests work on dart2js.
+
 ## 0.5.2
 
 * make PbMixin constructor public for use within protoc plugin.

diff --git a/lib/src/protobuf/coded_buffer_reader.dart b/lib/src/protobuf/coded_buffer_reader.dart
@@ -16,16 +16,13 @@ class CodedBufferReader {
   final int _recursionLimit;
   final int _sizeLimit;
 
-  CodedBufferReader(
-      List<int> buffer,
+  CodedBufferReader(List<int> buffer,
       {int recursionLimit: DEFAULT_RECURSION_LIMIT,
-      int sizeLimit: DEFAULT_SIZE_LIMIT}) :
-      _buffer =
-          buffer is Uint8List
-            ? buffer
-            : new Uint8List(buffer.length)..setRange(0, buffer.length, buffer),
-      _recursionLimit = recursionLimit,
-      _sizeLimit = math.min(sizeLimit, buffer.length) {
+      int sizeLimit: DEFAULT_SIZE_LIMIT})
+      : _buffer = buffer is Uint8List ? buffer : new Uint8List(buffer.length)
+          ..setRange(0, buffer.length, buffer),
+        _recursionLimit = recursionLimit,
+        _sizeLimit = math.min(sizeLimit, buffer.length) {
     _currentLimit = _sizeLimit;
   }
 
@@ -62,7 +59,7 @@ class CodedBufferReader {
   }
 
   void readGroup(int fieldNumber, GeneratedMessage message,
-                 ExtensionRegistry extensionRegistry) {
+      ExtensionRegistry extensionRegistry) {
     if (_recursionDepth >= _recursionLimit) {
       throw new InvalidProtocolBufferException.recursionLimitExceeded();
     }
@@ -84,8 +81,8 @@ class CodedBufferReader {
     return unknownFieldSet;
   }
 
-  void readMessage(GeneratedMessage message,
-                   ExtensionRegistry extensionRegistry) {
+  void readMessage(
+      GeneratedMessage message, ExtensionRegistry extensionRegistry) {
     int length = readInt32();
     if (_recursionDepth >= _recursionLimit) {
       throw new InvalidProtocolBufferException.recursionLimitExceeded();
@@ -123,13 +120,15 @@ class CodedBufferReader {
     var view = new Uint8List.view(data.buffer, data.offsetInBytes, 8);
     return new Int64.fromBytes(view);
   }
+
   bool readBool() => _readRawVarint32() != 0;
   List<int> readBytes() {
     int length = readInt32();
     _checkLimit(length);
-    return new Uint8List.view(_buffer.buffer,
-        _buffer.offsetInBytes + _bufferPos - length, length);
+    return new Uint8List.view(
+        _buffer.buffer, _buffer.offsetInBytes + _bufferPos - length, length);
   }
+
   String readString() => _UTF8.decode(readBytes());
   double readFloat() =>
       _readByteData(4).getFloat32(0, Endianness.LITTLE_ENDIAN);
@@ -150,8 +149,11 @@ class CodedBufferReader {
   }
 
   static int _decodeZigZag32(int value) {
-    if ((value & 0x1) == 1) value = -value;
-    return value >> 1;
+    if ((value & 0x1) == 1) {
+      return -(value >> 1) - 1;
+    } else {
+      return value >> 1;
+    }
   }
 
   static Int64 _decodeZigZag64(Int64 value) {

diff --git a/test/codec_test.dart b/test/codec_test.dart
@@ -3,7 +3,6 @@
 // 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.
 
-@TestOn("dart-vm")
 library pb_codec_tests;
 
 import 'dart:typed_data';
@@ -186,20 +185,22 @@ void main() {
     expect(readFloat(bits), doubleEquals(value));
   }
 
-  void _test64(List<int> hilo, double value) {
-    readDouble(int bits) {
-      var bytes = dataToBytes(
-          new ByteData(8)..setUint64(0, bits, Endianness.LITTLE_ENDIAN));
-      return new CodedBufferReader(bytes).readDouble();
-    }
+  final doubleToBytes = convertToBytes(PbFieldType.OD);
 
-    final doubleToBytes = convertToBytes(PbFieldType.OD);
-    doubleToBits(double value) =>
-        makeData(doubleToBytes(value)).getUint64(0, Endianness.LITTLE_ENDIAN);
-
-    int bits = (hilo[0] << 32) | hilo[1];
-    expect(doubleToBits(value), bits);
-    expect(readDouble(bits), doubleEquals(value));
+  void _test64(List<int> hilo, double value) {
+    // Encode a double to its wire format.
+    ByteData data = makeData(doubleToBytes(value));
+    var actualHilo = [
+      data.getUint32(4, Endianness.LITTLE_ENDIAN),
+      data.getUint32(0, Endianness.LITTLE_ENDIAN)
+    ];
+    //int encoded = data.getUint64(0, Endianness.LITTLE_ENDIAN);
+    expect(actualHilo, hilo);
+
+    // Decode it again (round trip).
+    List<int> bytes = dataToBytes(data);
+    double reencoded = new CodedBufferReader(bytes).readDouble();
+    expect(reencoded, doubleEquals(value));
   }
 
   test('testFloat', () {