emqtt_failover

%%--------------------------------------------------------------------
%% Copyright (c) 2022 EMQ Technologies Co., Ltd. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%--------------------------------------------------------------------

%% Note: this module CAN'T be hot-patched to avoid invalidating the
%% closures, so it must not be changed.
-module(emqtt_secret).

%% API:
-export([wrap/1, unwrap/1]).

-export_type([t/1]).

-type t(T) :: fun(() -> T).

%%================================================================================
%% API funcions
%%================================================================================

-spec wrap(T) -> t(T).
wrap(Term) ->
    fun() ->
        Term
    end.

-spec unwrap(t(T) | T) -> T.
unwrap(Term) when is_function(Term, 0) ->
    %% Handle potentially nested funs
    unwrap(Term());
unwrap(Term) ->
    Term.