Better errors for pkg/fixnum

pkg/fixnum/test/int_32_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 Int32test;
 import 'package:fixnum/fixnum.dart';
 import 'package:unittest/unittest.dart';
 
 void main() {
   group("isX tests", () {
@@ skipping 255 matching lines @@
   });
 
   group("conversions", () {
     test("toSigned", () {
       expect(Int32.ONE.toSigned(2), Int32.ONE);
       expect(Int32.ONE.toSigned(1), -Int32.ONE);
       expect(Int32.MAX_VALUE.toSigned(32), Int32.MAX_VALUE);
       expect(Int32.MIN_VALUE.toSigned(32), Int32.MIN_VALUE);
       expect(Int32.MAX_VALUE.toSigned(31), -Int32.ONE);
       expect(Int32.MIN_VALUE.toSigned(31), Int32.ZERO);
-      expect(() => Int32.ONE.toSigned(0), throws);
-      expect(() => Int32.ONE.toSigned(33), throws);
+      expect(() => Int32.ONE.toSigned(0), throwsRangeError);
+      expect(() => Int32.ONE.toSigned(33), throwsRangeError);
     });
     test("toUnsigned", () {
       expect(Int32.ONE.toUnsigned(1), Int32.ONE);
       expect(Int32.ONE.toUnsigned(0), Int32.ZERO);
       expect(Int32.MAX_VALUE.toUnsigned(32), Int32.MAX_VALUE);
       expect(Int32.MIN_VALUE.toUnsigned(32), Int32.MIN_VALUE);
       expect(Int32.MAX_VALUE.toUnsigned(31), Int32.MAX_VALUE);
       expect(Int32.MIN_VALUE.toUnsigned(31), Int32.ZERO);
-      expect(() => Int32.ONE.toUnsigned(-1), throws);
-      expect(() => Int32.ONE.toUnsigned(33), throws);
+      expect(() => Int32.ONE.toUnsigned(-1), throwsRangeError);
+      expect(() => Int32.ONE.toUnsigned(33), throwsRangeError);
     });
     test("toDouble", () {
       expect(new Int32(17).toDouble(), same(17.0));
       expect(new Int32(-17).toDouble(), same(-17.0));
     });
     test("toInt", () {
       expect(new Int32(17).toInt(), 17);
       expect(new Int32(-17).toInt(), -17);
     });
     test("toInt32", () {
@@ skipping 60 matching lines @@
       expect(new Int32(-1).shiftRightUnsigned(8).toHexString(), "ffffff");
     });
   });
 
   group("toRadixString", () {
     test("returns base n string representation", () {
       expect(new Int32(123456789).toRadixString(5), "223101104124");
     });
   });
 }