message: luckily I have tests
diff: @@ -14,8 +14,12 @@ export default class Suite {
  this.removeTestCase = this.removeTestCase.bind(this);
  }
  + isTest(test) {
  + return (test && test.constructor.name === "TestCase");
  + }
  +
  @action addTestCase(test) {
  - if (!test || test.constructor.name !== "TestCase") {
  + if (!this.isTest(test)) {
  throw new Error(`Expected to receive TestCase instead received ${test ? test.constructor.name : test}`);
  } else {
  this.tests.push(test);
  @@ -24,10 +28,18 @@ export default class Suite {
  }
  @action removeTestCase(test) {
  - if (!test || test.constructor.name !== "TestCase") {
  + if (!this.isTest(test)) {
  throw new Error(`Expected to receive TestCase instead received ${test ? test.constructor.name : test}`);
  } else {
  this.tests.remove(test);
  }
  }
  +
  + @action replaceTestCases(tests) {
  + if (tests.filter(test => !this.isTest(test)).length) {
  + throw new Error("Expected to receive array of TestCase");
  + } else {
  + this.tests.replace(SortBy([...tests], "name"));
  + }
  + }
  }
  