Merge the work on Generic Types Reification from 'dart-lang/reify' repo

pkg/kernel/testcases/reify/test_base.dart

+// Copyright (c) 2016, 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 test_base;
+
+expectIs(expected, actual, [String note]) {
+  if (expected != actual) {
+    if (note != null) {
+      throw "Expected: '$expected': $note, actual: '$actual'";
+    }
+    throw "Expected: '$expected', actual: '$actual'";
+  }
+}
+
+expectTrue(actual) => expectIs(true, actual);
+
+expectFalse(actual) => expectIs(false, actual);
+
+expectThrows(f(), test(e)) {
+  var exception = false;
+  String note = null;
+  try {
+    f();
+  } catch (e) {
+    exception = test(e);
+    if (!exception) {
+      note = "$e [${e.runtimeType}]";
+    }
+  }
+  expectIs(true, exception, note);
+}
+
+expectOutput(String expected) => expectIs(expected, output);
+
+String output;
+
+write(o) {
+  output = output == null ? "$o" : "$output\n$o";
+}