message: fixed 0 condition
diff: @@ -12,6 +12,8 @@ export default class TestCase {
  this.name = name;
  this.createCommand = this.createCommand.bind(this);
  this.removeCommand = this.removeCommand.bind(this);
  + this.insertCommandAt = this.insertCommandAt.bind(this);
  + this.swapCommands = this.swapCommands.bind(this);
  }
  @action createCommand() {
  @@ -23,8 +25,8 @@ export default class TestCase {
  @action insertCommandAt(command, index) {
  if (!command || command.constructor.name !== "Command") {
  throw new Error(`Expected to receive Command instead received ${command ? command.constructor.name : command}`);
  - } else if (!index || index.constructor.name !== "Number") {
  - throw new Error(`Expected to receive Number instead received ${index ? index.constructor.name : index}`);
  + } else if (index === undefined || index.constructor.name !== "Number") {
  + throw new Error(`Expected to receive Number instead received ${index !== undefined ? index.constructor.name : index}`);
  } else {
  this.commands.splice(index, 0, command);
  }
  