Timewrap

Timewrap is a "Time-Wrapper" through which you can access different time-sources, Elixir and Erlang offers you. Other than that you can implement on your own.

Also, Timewrap can do the time-warp, freeze, and unfreeze a Timewrap.Timer.

You can instantiate different Timewrap.Timers, registered and supervised by :name.

The Timewrap.TimeSupervisor is started with the Timewrap.Application and implicitly starts the default timer :default_timer. This one is used whenever you call Timewrap-functions without a timer given as the first argument.

Examples:

The best way to figure out how you can use this library is by having a look at this Test suite.

use Timewrap # imports some handy Timewrap-functions.

With default Timer

Timewrap.freeze_timer()
item1 = %{ time: current_time() }
:timer.sleep(1000)
item2 = %{ time: current_time() }
assert item1.time == item2.time

Transactions with a given and frozen time

with_frozen_timer(~N[1964-08-31 06:00:00Z], fn ->
  ... do something while `current_time` will 
  always return the given timestamp within this
  block...
end )

Start several independent timers

{:ok, today} = new_timer(:today)
{:ok, next_week} = new_timer(:next_week)
freeze_time(:today, ~N[2019-02-11 09:00:00])
freeze_time(:next_week, ~N[2019-02-18 09:00:00])
... do something ...
unfreeze_time(:today)
unfreeze_time(:next_week)

Installation

From available Hex package, the package can be installed by adding timewrap to your list of dependencies in mix.exs:

def deps do
  [
    {:timewrap, "~> 0.1.3"}
  ]
end

Configuration

config/config.exs

  config :timewrap,
    timer: :default,
    unit: :second,
    calendar: Calendar.ISO,
    representation: :unix

lib/your_app/application.ex

  use Application

  @impl true
  def start(_type, _args) do
    # List all child processes to be supervised
    children = [
      # Starts a worker by calling: Timewrap.Worker.start_link(arg)
      {Timewrap.TimeSupervisor, strategy: :one_for_one, name: Timewrap.TimeSupervisor} #<---ADD THIS
    ]

    # See https://hexdocs.pm/elixir/Supervisor.html
    # for other strategies and supported options
    opts = [strategy: :one_for_one, name: Timewrap.Supervisor]
    Supervisor.start_link(children, opts)
  end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/timewrap.

timewrap