Start cleaning up the HTML tests.

pkg/dev_compiler/test/codegen/minitest.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.
+
+/// A minimal, dependency-free emulation layer for a subset of the
+/// unittest/test API used by the language and core library (especially HTML)
+/// tests.
+///
+/// A number of our language and core library tests were written against the
+/// unittest package, which is now deprecated in favor of the new test package.
+/// The latter is much better feature-wise, but is also quite complex and has
+/// many dependencies. For low-level language and core library tests, we don't
+/// want to have to pull in a large number of dependencies and be able to run
+/// them correctly in order to run a test, so we want to test them against
+/// something simpler.
+///
+/// When possible, we just use the tiny expect library. But to avoid rewriting
+/// all of the existing tests that use unittest, they can instead use this,
+/// which shims the unittest API with as little code as possible and calls into
+/// expect.
+///
+/// Eventually, it would be good to refactor those tests to use the expect
+/// package directly and remove this.
+
+import 'package:expect/expect.dart';
+
+typedef void _Action();
+typedef void _ExpectationFunction(Object actual);
+
+final List<_Group> _groups = [new _Group()];
+
+final Object isFalse = new _Expectation(Expect.isFalse);
+final Object isNotNull = new _Expectation(Expect.isNotNull);
+final Object isNull = new _Expectation(Expect.isNull);
+final Object isTrue = new _Expectation(Expect.isTrue);
+
+final Object returnsNormally = new _Expectation((actual) {
+  try {
+    (actual as _Action)();
+  } catch (error) {
+    Expect.fail("Expected function to return normally, but threw:\n$error");
+  }
+});
+
+final Object throws = new _Expectation((actual) {
+  Expect.throws(actual as _Action);
+});
+
+final Object throwsArgumentError = new _Expectation((actual) {
+  Expect.throws(actual as _Action, (error) => error is ArgumentError);
+});
+
+final Object throwsNoSuchMethodError = new _Expectation((actual) {
+  Expect.throws(actual as _Action, (error) => error is NoSuchMethodError);
+});
+
+final Object throwsRangeError = new _Expectation((actual) {
+  Expect.throws(actual as _Action, (error) => error is RangeError);
+});
+
+final Object throwsStateError = new _Expectation((actual) {
+  Expect.throws(actual as _Action, (error) => error is StateError);
+});
+
+final Object throwsUnsupportedError = new _Expectation((actual) {
+  Expect.throws(actual as _Action, (error) => error is UnsupportedError);
+});
+
+/// The test runner should call this once after running a test file.
+void finishTests() {
+  _groups.clear();
+  _groups.add(new _Group());
+}
+
+void group(String description, body()) {
+  // TODO(rnystrom): Do something useful with the description.
+  _groups.add(new _Group());
+
+  try {
+    body();
+  } finally {
+    _groups.removeLast();
+  }
+}
+
+void test(String description, body()) {
+  // TODO(rnystrom): Do something useful with the description.
+  for (var group in _groups) {
+    if (group.setUpFunction != null) group.setUpFunction();
+  }
+
+  try {
+    body();
+  } finally {
+    for (var i = _groups.length - 1; i >= 0; i--) {
+      var group = _groups[i];
+      if (group.tearDownFunction != null) group.tearDownFunction();
+    }
+  }
+}
+
+void setUp(body()) {
+  // Can't define multiple setUps at the same level.
+  assert(_groups.last.setUpFunction == null);
+  _groups.last.setUpFunction = body;
+}
+
+void tearDown(body()) {
+  // Can't define multiple tearDowns at the same level.
+  assert(_groups.last.tearDownFunction == null);
+  _groups.last.tearDownFunction = body;
+}
+
+void expect(Object actual, Object expected, {String reason}) {
+  // TODO(rnystrom): Do something useful with reason.
+  if (expected is! _Expectation) {
+    expected = equals(expected);
+  }
+
+  var expectation = expected as _Expectation;
+  expectation.function(actual);
+}
+
+void fail(String message) {
+  Expect.fail(message);
+}
+
+Object equals(Object value) => new _Expectation((actual) {
+      Expect.deepEquals(value, actual);
+    });
+
+Object notEquals(Object value) => new _Expectation((actual) {
+      Expect.notEquals(value, actual);
+    });
+
+Object unorderedEquals(Object value) => new _Expectation((actual) {
+      Expect.setEquals(value, actual);
+    });
+
+// TODO(bob): Do something useful with the description.
+Object predicate(bool fn(Object value), [String description]) =>
+    new _Expectation((actual) {
+      Expect.isTrue(fn(actual));
+    });
+
+Object inInclusiveRange(num min, num max) => new _Expectation((actual) {
+      var actualNum = actual as num;
+      if (actualNum < min || actualNum > max) {
+        fail("Expected $actualNum to be in the inclusive range [$min, $max].");
+      }
+    });
+
+Object greaterThan(num value) => new _Expectation((actual) {
+      var actualNum = actual as num;
+      if (actualNum <= value) {
+        fail("Expected $actualNum to be greater than $value.");
+      }
+    });
+
+Object same(Object value) => new _Expectation((actual) {
+      Expect.identical(value, actual);
+    });
+
+/// One level of group() nesting to track an optional [setUp()] and [tearDown()]
+/// function for the group.
+///
+/// There is also an implicit top level group.
+class _Group {
+  _Action setUpFunction;
+  _Action tearDownFunction;
+}
+
+/// A wrapper around an expectation function.
+///
+/// This function is passed the actual value and should throw an
+/// [ExpectException] if the value doesn't match the expectation.
+class _Expectation {
+  final _ExpectationFunction function;
+
+  _Expectation(this.function);
+}