unittest: refactor ahead of matcher changes

test/future_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.future_matchers_test;
+
+import 'dart:async';
+
+import 'package:metatest/metatest.dart';
+import 'package:unittest/unittest.dart';
+
+void main() => initTests(_test);
+
+void _test(message) {
+  initMetatest(message);
+
+  expectTestResults('group name test', () {
+    test('completes - unexpected error', () {
+      var completer = new Completer();
+      completer.completeError('X');
+      expect(completer.future, completes);
+    });
+
+    test('completes - successfully', () {
+      var completer = new Completer();
+      completer.complete('1');
+      expect(completer.future, completes);
+    });
+
+    test('throws - unexpected to see normal completion', () {
+      var completer = new Completer();
+      completer.complete('1');
+      expect(completer.future, throws);
+    });
+
+    test('throws - expected to see exception', () {
+      var completer = new Completer();
+      completer.completeError('X');
+      expect(completer.future, throws);
+    });
+
+    test('throws - expected to see exception thrown later on', () {
+      var completer = new Completer();
+      var chained = completer.future.then((_) {
+        throw 'X';
+      });
+      expect(chained, throws);
+      completer.complete('1');
+    });
+
+    test('throwsA - unexpected normal completion', () {
+      var completer = new Completer();
+      completer.complete('1');
+      expect(completer.future, throwsA(equals('X')));
+    });
+
+    test('throwsA - correct error', () {
+      var completer = new Completer();
+      completer.completeError('X');
+      expect(completer.future, throwsA(equals('X')));
+    });
+
+    test('throwsA - wrong error', () {
+      var completer = new Completer();
+      completer.completeError('X');
+      expect(completer.future, throwsA(equals('Y')));
+    });
+  }, [
+    {
+      'result': 'fail',
+      'message': 'Expected future to complete successfully, but it failed with '
+          'X',
+    },
+    {'result': 'pass'},
+    {
+      'result': 'fail',
+      'message': 'Expected future to fail, but succeeded with \'1\'.'
+    },
+    {'result': 'pass'},
+    {'result': 'pass'},
+    {
+      'result': 'fail',
+      'message': 'Expected future to fail, but succeeded with \'1\'.'
+    },
+    {'result': 'pass'},
+    {
+      'result': 'fail',
+      'message': '''Expected: 'Y'
+  Actual: 'X'
+   Which: is different.
+Expected: Y
+  Actual: X
+          ^
+ Differ at offset 0
+'''
+    }
+  ]);
+}