Tests for https://gist.github.com/ronualdo/370c9c258cc0c1131fa5ced6b7282878

flatten_test.exs

defmodule FlattenTest do
  use ExUnit.Case
  doctest Flatten

  test "flats an empty array" do
    assert Flatten.flat([]) == []
  end

  test "flats an array with just one element" do
    assert Flatten.flat([1]) == [1]
  end

  test "flats an array with two elements" do
    assert Flatten.flat([1, 2]) == [1, 2]
  end

  test "flats an array that contains an empty array" do
    assert Flatten.flat([[]]) == []
  end

  test "flats an array that contains numbers and an empty array" do
    assert Flatten.flat([1, 2, [3], 4]) == [1, 2, 3, 4]
  end

  test "flats a number array that contains another number array" do
    assert Flatten.flat([1, 2, [1, 2, 3], 4]) == [1, 2, 1, 2, 3, 4]
  end

  test "flats a number array with an empty multi index array" do
    assert Flatten.flat([1, 2, 3, [[[]]], 4]) == [1, 2, 3, 4]
  end

  test "flats a number array with anothe multi index array" do
    assert Flatten.flat([1, 2, [[[3]]], 4]) == [1, 2, 3, 4]
  end

  test "flats an array with number arrays" do
    assert Flatten.flat([[1], [2, 3], [[4, 5, [[6]]]]]) == [1, 2, 3, 4, 5, 6]
  end
end