test: add comprehensive tests for membership fee UI components

Add tests for all membership fee UI components following TDD principles:

test/mv_web/helpers/membership_fee_helpers_test.exs

@@ -0,0 +1,197 @@
+defmodule MvWeb.Helpers.MembershipFeeHelpersTest do
+  @moduledoc """
+  Tests for MembershipFeeHelpers module.
+  """
+  use ExUnit.Case, async: true
+
+  alias MvWeb.Helpers.MembershipFeeHelpers
+  alias Mv.MembershipFees.CalendarCycles
+
+  describe "format_currency/1" do
+    test "formats decimal amount correctly" do
+      assert MembershipFeeHelpers.format_currency(Decimal.new("60.00")) == "60,00 €"
+      assert MembershipFeeHelpers.format_currency(Decimal.new("5.5")) == "5,50 €"
+      assert MembershipFeeHelpers.format_currency(Decimal.new("100")) == "100,00 €"
+      assert MembershipFeeHelpers.format_currency(Decimal.new("0.99")) == "0,99 €"
+    end
+  end
+
+  describe "format_interval/1" do
+    test "formats all interval types correctly" do
+      assert MembershipFeeHelpers.format_interval(:monthly) == "Monthly"
+      assert MembershipFeeHelpers.format_interval(:quarterly) == "Quarterly"
+      assert MembershipFeeHelpers.format_interval(:half_yearly) == "Half-yearly"
+      assert MembershipFeeHelpers.format_interval(:yearly) == "Yearly"
+    end
+  end
+
+  describe "format_cycle_range/2" do
+    test "formats yearly cycle range correctly" do
+      cycle_start = ~D[2024-01-01]
+      interval = :yearly
+      cycle_end = CalendarCycles.calculate_cycle_end(cycle_start, interval)
+
+      result = MembershipFeeHelpers.format_cycle_range(cycle_start, interval)
+      assert result =~ "2024"
+      assert result =~ "01.01"
+      assert result =~ "31.12"
+    end
+
+    test "formats quarterly cycle range correctly" do
+      cycle_start = ~D[2024-01-01]
+      interval = :quarterly
+      cycle_end = CalendarCycles.calculate_cycle_end(cycle_start, interval)
+
+      result = MembershipFeeHelpers.format_cycle_range(cycle_start, interval)
+      assert result =~ "2024"
+      assert result =~ "01.01"
+      assert result =~ "31.03"
+    end
+
+    test "formats monthly cycle range correctly" do
+      cycle_start = ~D[2024-03-01]
+      interval = :monthly
+      cycle_end = CalendarCycles.calculate_cycle_end(cycle_start, interval)
+
+      result = MembershipFeeHelpers.format_cycle_range(cycle_start, interval)
+      assert result =~ "2024"
+      assert result =~ "01.03"
+      assert result =~ "31.03"
+    end
+  end
+
+  describe "get_last_completed_cycle/2" do
+    test "returns last completed cycle for member" do
+      # Create test data
+      fee_type =
+        Mv.MembershipFees.MembershipFeeType
+        |> Ash.Changeset.for_create(:create, %{
+          name: "Test Type",
+          amount: Decimal.new("50.00"),
+          interval: :yearly
+        })
+        |> Ash.create!()
+
+      member =
+        Mv.Membership.Member
+        |> Ash.Changeset.for_create(:create_member, %{
+          first_name: "Test",
+          last_name: "Member",
+          email: "test#{System.unique_integer([:positive])}@example.com",
+          membership_fee_type_id: fee_type.id,
+          join_date: ~D[2022-01-01]
+        })
+        |> Ash.create!()
+
+      # Create cycles
+      cycle_2022 =
+        Mv.MembershipFees.MembershipFeeCycle
+        |> Ash.Changeset.for_create(:create, %{
+          cycle_start: ~D[2022-01-01],
+          amount: Decimal.new("50.00"),
+          member_id: member.id,
+          membership_fee_type_id: fee_type.id,
+          status: :paid
+        })
+        |> Ash.create!()
+
+      cycle_2023 =
+        Mv.MembershipFees.MembershipFeeCycle
+        |> Ash.Changeset.for_create(:create, %{
+          cycle_start: ~D[2023-01-01],
+          amount: Decimal.new("50.00"),
+          member_id: member.id,
+          membership_fee_type_id: fee_type.id,
+          status: :paid
+        })
+        |> Ash.create!()
+
+      # Assuming we're in 2024, last completed should be 2023
+      last_cycle = MembershipFeeHelpers.get_last_completed_cycle(member, Date.utc_today())
+
+      assert last_cycle.id == cycle_2023.id
+    end
+
+    test "returns nil if no cycles exist" do
+      fee_type =
+        Mv.MembershipFees.MembershipFeeType
+        |> Ash.Changeset.for_create(:create, %{
+          name: "Test Type",
+          amount: Decimal.new("50.00"),
+          interval: :yearly
+        })
+        |> Ash.create!()
+
+      member =
+        Mv.Membership.Member
+        |> Ash.Changeset.for_create(:create_member, %{
+          first_name: "Test",
+          last_name: "Member",
+          email: "test#{System.unique_integer([:positive])}@example.com",
+          membership_fee_type_id: fee_type.id
+        })
+        |> Ash.create!()
+
+      last_cycle = MembershipFeeHelpers.get_last_completed_cycle(member, Date.utc_today())
+      assert last_cycle == nil
+    end
+  end
+
+  describe "get_current_cycle/2" do
+    test "returns current cycle for member" do
+      fee_type =
+        Mv.MembershipFees.MembershipFeeType
+        |> Ash.Changeset.for_create(:create, %{
+          name: "Test Type",
+          amount: Decimal.new("50.00"),
+          interval: :yearly
+        })
+        |> Ash.create!()
+
+      member =
+        Mv.Membership.Member
+        |> Ash.Changeset.for_create(:create_member, %{
+          first_name: "Test",
+          last_name: "Member",
+          email: "test#{System.unique_integer([:positive])}@example.com",
+          membership_fee_type_id: fee_type.id,
+          join_date: ~D[2023-01-01]
+        })
+        |> Ash.create!()
+
+      today = Date.utc_today()
+      current_year_start = %{today | month: 1, day: 1}
+
+      current_cycle =
+        Mv.MembershipFees.MembershipFeeCycle
+        |> Ash.Changeset.for_create(:create, %{
+          cycle_start: current_year_start,
+          amount: Decimal.new("50.00"),
+          member_id: member.id,
+          membership_fee_type_id: fee_type.id,
+          status: :unpaid
+        })
+        |> Ash.create!()
+
+      result = MembershipFeeHelpers.get_current_cycle(member, today)
+
+      assert result.id == current_cycle.id
+    end
+  end
+
+  describe "status_color/1" do
+    test "returns correct color classes for statuses" do
+      assert MembershipFeeHelpers.status_color(:paid) == "text-success"
+      assert MembershipFeeHelpers.status_color(:unpaid) == "text-error"
+      assert MembershipFeeHelpers.status_color(:suspended) == "text-base-content/60"
+    end
+  end
+
+  describe "status_icon/1" do
+    test "returns correct icon names for statuses" do
+      assert MembershipFeeHelpers.status_icon(:paid) == "hero-check-circle"
+      assert MembershipFeeHelpers.status_icon(:unpaid) == "hero-x-circle"
+      assert MembershipFeeHelpers.status_icon(:suspended) == "hero-pause-circle"
+    end
+  end
+end