test: fee type column visibility, CSV export, export controller

FieldVisibility pseudo fields and visible selection; MembersCSV fee type
column; export accepts membership_fee_type and returns Fee Type column.

test/mv/membership/members_csv_test.exs

@@ -199,6 +199,43 @@ defmodule Mv.Membership.MembersCSVTest do
       assert csv =~ "M,m@m.com,Paid"
     end
 
+    test "membership_fee_type column exports fee type name" do
+      columns = [
+        %{header: "First Name", kind: :member_field, key: "first_name"},
+        %{header: "Email", kind: :member_field, key: "email"},
+        %{header: "Fee Type", kind: :membership_fee_type, key: :membership_fee_type}
+      ]
+
+      member = %{
+        first_name: "M",
+        email: "m@m.com",
+        membership_fee_type: %{id: "ft-1", name: "Standard"}
+      }
+
+      iodata = MembersCSV.export([member], columns)
+      csv = IO.iodata_to_binary(iodata)
+
+      assert csv =~ "Fee Type"
+      assert csv =~ "Standard"
+      assert csv =~ "M,m@m.com,Standard"
+    end
+
+    test "membership_fee_type column exports empty when no fee type" do
+      columns = [
+        %{header: "First Name", kind: :member_field, key: "first_name"},
+        %{header: "Fee Type", kind: :membership_fee_type, key: :membership_fee_type}
+      ]
+
+      member = %{first_name: "M", email: "m@m.com", membership_fee_type: nil}
+
+      iodata = MembersCSV.export([member], columns)
+      csv = IO.iodata_to_binary(iodata)
+
+      assert csv =~ "Fee Type"
+      assert csv =~ "M,"
+      refute csv =~ "Standard"
+    end
+
     test "CSV injection: formula-like and dangerous prefixes are escaped with apostrophe" do
       member = %{
         first_name: "=SUM(A1:A10)",