import Alert from "@material-ui/lab/Alert";

 const loginHandler = e => {
    e.preventDefault();
    formData.username = formData.username.replace(/[^0-9]/g, "");
    // Assuming that, all network Request is successfull, and the user is authenticated
    axios
      .post("url", formData)

      .then(res => {
        if (res.status === 200) {
          if (
            signIn({
              token: res.data.token, //Just a random token
              tokenType: "Bearer", // Token type set as Bearer
              authState: { name: formData.username },
              expiresIn: 120, // Token Expriration time, in minutes
            })
          ) {
            // If Login Successfull, then Redirect the user to secure route
            history.push("/users");
          }
        } else {
          // Else, there must be some error. So, throw an error
          alert("res.data");
        }
      })
      .catch(error => {
        // alert("Неверные данные \n" + error);
        return (
          <Alert severity="error">This is an error alert — check it out!</Alert>
        );
      });
  };