message: workflow cancelation reason + canceling only once
diff: @@ -138,6 +138,16 @@ module('Unit | Workflow model', function (hooks) {
  workflow.milestones = [exampleMilestone];
  workflow.cancel('TEST');
  assert.equal(workflow.isCanceled, true);
  + assert.equal(workflow.cancelationReason, 'TEST');
  + });
  +
  + test('Workflow cannot be canceled twice', function (assert) {
  + let workflow = new ConcreteWorkflow({});
  + workflow.milestones = [exampleMilestone];
  + workflow.cancel('FIRST');
  + workflow.cancel('SECOND');
  + assert.equal(workflow.isCanceled, true);
  + assert.equal(workflow.cancelationReason, 'FIRST');
  });
  test('Completed workflow is not canceled when workflow.cancel is called', function (assert) {
  