尽管承诺得到了解决,但为什么要打官司?

有人能帮我理解为什么要打.catch的案子,尽管先前的承诺已经成功解决了? https://gist.github.com/defrian/fd6dd7f072754e833b60c7bd6ed45159 当密码正确时,我收到(为什么它包含_有效负载_:_登录错误_?)

    Array [
        Object {
          "type": "login_user",
        },
       Object {
         "payload": Object {
           "name": "signedUser",
         },
         "type": "login_user_success",
       },
       Object {
         "payload": "Cannot read property 'dispatch' of undefined",
         "type": "login_user_fail",
       },
      ]

当我使用错误的密码时,我会收到(如我所料)

Array [
        Object {
          "type": "login_user",
        },
       Object {
         "payload": "signIn error ",
         "type": "login_user_fail",
       },
      ]