Functional Programming: A PragPub Anthology

Condense and Combine the Measurements

We can still do better. In the previous test, we have only one measurement. Typically, we’ll have more than one. When that happens, our verify block can group several different measurements together, like this:

      defmodule AppTest do
  use ExUnit.Case
  use TrueStory

  use ExUnit.Case
  use TrueStory

  def set_map_key(c) do
    Map.put :setup, :done
  end

  def set_second_key(c) do
    Map.put :test, :true_story
  end

  story "two context keys", c
    |> set_map_key
    |> set_second_key,
  verify do
    assert :setup in Map.keys(c)
    assert :test in Map.keys(c)
    refute :not_present in Map.keys(c)
  end
end

The grouping is an improvement. It does two ...