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_web/controllers/member_export_controller_test.exs

@@ -146,6 +146,37 @@ defmodule MvWeb.MemberExportControllerTest do
       refute header =~ "unknown_field"
     end
 
+    test "export includes membership_fee_type column when requested", %{
+      conn: conn,
+      member1: m1
+    } do
+      payload = %{
+        "selected_ids" => [m1.id],
+        "member_fields" => ["first_name", "membership_fee_type", "email"],
+        "custom_field_ids" => [],
+        "query" => nil,
+        "sort_field" => nil,
+        "sort_order" => nil
+      }
+
+      conn = get(conn, "/members")
+      csrf_token = csrf_token_from_conn(conn)
+
+      conn =
+        post(conn, "/members/export.csv", %{
+          "payload" => Jason.encode!(payload),
+          "_csrf_token" => csrf_token
+        })
+
+      assert conn.status == 200
+      body = response(conn, 200)
+      header = body |> export_lines() |> hd()
+
+      # Fee Type column is included (label from MemberFields.label(:membership_fee_type))
+      assert header =~ "Fee Type"
+      assert body =~ "Alice"
+    end
+
     test "export includes membership_fee_status computed field when requested", %{
       conn: conn,
       member1: m1