// Copyright (c) 2014, 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 reflective_tests;

import 'dart:async';

@MirrorsUsed(metaTargets: 'ReflectiveTestCase')
import 'dart:mirrors';

import 'package:unittest/unittest.dart';


/**
 * A marker annotation used to instruct dart2js to keep reflection information
 * for the annotated classes.
 */
class ReflectiveTestCase {
  const ReflectiveTestCase();
}


/**
 * Runs test methods existing in the given [type].
 *
 * Methods with names starting with `test` are run using [test] function.
 * Methods with names starting with `solo_test` are run using [solo_test] function.
 *
 * Each method is run with a new instance of [type].
 * So, [type] should have a default constructor.
 *
 * If [type] declares method `setUp`, it methods will be invoked before any test
 * method invocation.
 *
 * If [type] declares method `tearDown`, it will be invoked after any test
 * method invocation. If method returns [Future] to test some asyncronous
 * behavior, then `tearDown` will be invoked in `Future.complete`.
 */
void runReflectiveTests(Type type) {
  ClassMirror classMirror = reflectClass(type);
  String className = MirrorSystem.getName(classMirror.simpleName);
  group(className, () {
    classMirror.instanceMembers.forEach((symbol, memberMirror) {
      // we need only methods
      if (memberMirror is! MethodMirror || !memberMirror.isRegularMethod) {
        return;
      }
      String memberName = MirrorSystem.getName(symbol);
      // test_
      if (memberName.startsWith('test_')) {
        String testName = memberName.substring('test_'.length);
        test(testName, () {
          return _runTest(classMirror, symbol);
        });
        return;
      }
      // solo_test_
      if (memberName.startsWith('solo_test_')) {
        String testName = memberName.substring('solo_test_'.length);
        solo_test(testName, () {
          return _runTest(classMirror, symbol);
        });
      }
    });
  });
}


_runTest(ClassMirror classMirror, Symbol symbol) {
  InstanceMirror instanceMirror = classMirror.newInstance(new Symbol(''), []);
  return _invokeSymbolIfExists(instanceMirror, #setUp).then(
      (_) => instanceMirror.invoke(symbol, []).reflectee).whenComplete(
      () => _invokeSymbolIfExists(instanceMirror, #tearDown));
}


Future _invokeSymbolIfExists(InstanceMirror instanceMirror, Symbol symbol) {
  var invocationResult = null;
  try {
    invocationResult = instanceMirror.invoke(symbol, []).reflectee;
  } on NoSuchMethodError catch (e) {
  }
  if (invocationResult is Future) {
    return invocationResult;
  } else {
    return new Future.value(invocationResult);
  }
}