test: add tests to person

test/app/person_test.exs

@@ -0,0 +1,29 @@
+defmodule App.PersonTest do
+  use ExUnit.Case
+  alias App.Person
+
+  @doc """
+  Test for `get_person_id/1`
+  """
+  describe "get_person_id/1" do
+    test "returns id when person is present in assigns" do
+      assigns = %{person: %{id: 1}}
+      assert Person.get_person_id(assigns) == 1
+    end
+
+    test "returns 0 when person is not present in assigns" do
+      assigns = %{}
+      assert Person.get_person_id(assigns) == 0
+    end
+
+    test "returns 0 when id is not present in person" do
+      assigns = %{person: %{}}
+      assert Person.get_person_id(assigns) == 0
+    end
+
+    test "returns 0 when id is nil in person" do
+      assigns = %{person: %{id: nil}}
+      assert Person.get_person_id(assigns) == 0
+    end
+  end
+end