unittest: refactor ahead of matcher changes

test/throws_matchers_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 unittest.core_matchers_test;
+
+import 'package:unittest/unittest.dart';
+
+import 'test_utils.dart';
+
+doesNotThrow() {}
+doesThrow() {
+  throw 'X';
+}
+
+void main() {
+  test('throws', () {
+    shouldFail(doesNotThrow, throws, matches(r"Expected: throws"
+        r"  Actual: <Closure(: \(\) => dynamic "
+        r"from Function 'doesNotThrow': static\.)?>"
+        r"   Which: did not throw"));
+    shouldPass(doesThrow, throws);
+    shouldFail(true, throws, "Expected: throws"
+        "  Actual: <true>"
+        "   Which: is not a Function or Future");
+  });
+
+  test('throwsA', () {
+    shouldPass(doesThrow, throwsA(equals('X')));
+    shouldFail(doesThrow, throwsA(equals('Y')), matches(r"Expected: throws 'Y'"
+        r"  Actual: <Closure(: \(\) => dynamic "
+        r"from Function 'doesThrow': static\.)?>"
+        r"   Which: threw 'X'"));
+  });
+
+  test('throwsA', () {
+    shouldPass(doesThrow, throwsA(equals('X')));
+    shouldFail(doesThrow, throwsA(equals('Y')), matches("Expected: throws 'Y'.*"
+        "Actual: <Closure.*"
+        "Which: threw 'X'"));
+  });
+
+  group('exception/error matchers', () {
+    test('throwsCyclicInitializationError', () {
+      expect(() => _Bicycle.foo, throwsCyclicInitializationError);
+    });
+
+    test('throwsConcurrentModificationError', () {
+      expect(() {
+        var a = {'foo': 'bar'};
+        for (var k in a.keys) {
+          a.remove(k);
+        }
+      }, throwsConcurrentModificationError);
+    });
+
+    test('throwsNullThrownError', () {
+      expect(() => throw null, throwsNullThrownError);
+    });
+  });
+}
+
+class _Bicycle {
+  static final foo = bar();
+
+  static bar() {
+    return foo + 1;
+  }
+}