Add failing test: parses list of strings into first and last number t…

…uples

lib/day1/day1.ex

@@ -39,4 +39,8 @@ defmodule Day1 do
         |> String.split("\n", trim: true)
     end
   end
+
+  def parse_list_to_first_last_numbers(input_list) do
+    input_list |> Enum.map(&find_first_and_last_number/1)
+  end
 end

test/day1_test.exs

@@ -17,4 +17,13 @@ defmodule Day1Test do
              "third line of the file"
            ]
   end
+
+  test "parses list of strings into first and last number tuples" do
+    list = Day1.parse_file("./test/mocks/lines_of_text_w_numbers.txt", :string)
+    assert Day1.parse_list_to_first_last_numbers(list, :string) == [
+             {1, 3},
+             {4, 6},
+             {7, 9}
+           ]
+  end
 end

test/mocks/lines_of_text_w_numbers.txt

@@ -0,0 +1,3 @@
+abc123
+efg456
+hij789