Property-Based Testing with PropEr, Erlang, and Elixir

Parallel Tests

As with the last chapter, the parallel version of our system can be adapted by just declaring a new property and reusing the same model, to see if any glaring concurrency issue can be found.

You just have to add the parallel property to the same file:

Erlang              code/Bookstore/erlang/bookstore/test/prop_bookstore.erl

prop_parallel() ->
    ?SETUP(fun() ->
        {ok, Apps} = application:ensure_all_started(bookstore),
        fun() -> [application:stop(App) || App <- Apps], ok end
      end,
      ?FORALL(Cmds, parallel_commands(?MODULE),
        begin
            bookstore_db:setup(),
            {History, State, Result} = run_parallel_commands(?MODULE, Cmds),

        bookstore_db:teardown(),
        ?WHENFAIL(io:format("=======~n"
                            "Failing command ...