lib/mv_web/live/components/member_filter_component.ex

@@ -438,10 +438,18 @@ defmodule MvWeb.Components.MemberFilterComponent do
     payment_filter = parse_payment_filter(params)
 
     group_filters_parsed =
-      parse_prefix_filters(params, @group_filter_prefix, &FilterParams.parse_in_not_in_value/1)
+      FilterParams.parse_prefix_filters(
+        params,
+        @group_filter_prefix,
+        &FilterParams.parse_in_not_in_value/1
+      )
 
     fee_type_filters_parsed =
-      parse_prefix_filters(params, @fee_type_filter_prefix, &FilterParams.parse_in_not_in_value/1)
+      FilterParams.parse_prefix_filters(
+        params,
+        @fee_type_filter_prefix,
+        &FilterParams.parse_in_not_in_value/1
+      )
 
     custom_boolean_filters_parsed = parse_custom_boolean_filters(params)
 
@@ -486,17 +494,6 @@ defmodule MvWeb.Components.MemberFilterComponent do
     end
   end
 
-  defp parse_prefix_filters(params, prefix, parse_value_fn) do
-    prefix_len = String.length(prefix)
-
-    params
-    |> Enum.filter(fn {key, _} -> String.starts_with?(key, prefix) end)
-    |> Enum.reduce(%{}, fn {key, value_str}, acc ->
-      id_str = String.slice(key, prefix_len, String.length(key) - prefix_len)
-      Map.put(acc, id_str, parse_value_fn.(value_str))
-    end)
-  end
-
   defp parse_custom_boolean_filters(params) do
     params
     |> Map.get("custom_boolean", %{})

lib/mv_web/live/member_live/index.ex

@@ -36,6 +36,8 @@ defmodule MvWeb.MemberLive.Index do
   alias Mv.MembershipFees
   alias Mv.MembershipFees.MembershipFeeType
   alias MvWeb.Helpers.DateFormatter
+  alias MvWeb.MemberLive.Index.CustomFieldValueLookup
+  alias MvWeb.MemberLive.Index.DateFilter
   alias MvWeb.MemberLive.Index.FieldSelection
   alias MvWeb.MemberLive.Index.FieldVisibility
   alias MvWeb.MemberLive.Index.FilterParams
@@ -87,6 +89,13 @@ defmodule MvWeb.MemberLive.Index do
       |> Enum.filter(&(&1.value_type == :boolean))
       |> Enum.sort_by(& &1.name, :asc)
 
+    # Date-typed custom fields surface in the new "Custom date fields" filter
+    # section and are needed by DateFilter.from_params/2 to validate UUIDs.
+    date_custom_fields =
+      all_custom_fields
+      |> Enum.filter(&(&1.value_type == :date))
+      |> Enum.sort_by(& &1.name, :asc)
+
     # Load groups for filter dropdown (sorted by name)
     groups =
       Mv.Membership.Group
@@ -143,6 +152,8 @@ defmodule MvWeb.MemberLive.Index do
       |> assign(:custom_fields_visible, custom_fields_visible)
       |> assign(:all_custom_fields, all_custom_fields)
       |> assign(:boolean_custom_fields, boolean_custom_fields)
+      |> assign(:date_custom_fields, date_custom_fields)
+      |> assign(:date_filters, DateFilter.default())
       |> assign(:all_available_fields, all_available_fields)
       |> assign(:user_field_selection, initial_selection)
       |> assign(:fields_in_url?, false)
@@ -448,6 +459,25 @@ defmodule MvWeb.MemberLive.Index do
     {:noreply, push_patch(socket, to: new_path, replace: true)}
   end
 
+  @impl true
+  def handle_info({:date_filters_changed, new_date_filters}, socket) do
+    socket =
+      socket
+      |> assign(:date_filters, new_date_filters)
+      |> load_members()
+      |> update_selection_assigns()
+
+    query_params =
+      build_query_params(opts_for_query_params(socket, %{date_filters: new_date_filters}))
+      |> maybe_add_field_selection(
+        socket.assigns[:user_field_selection],
+        socket.assigns[:fields_in_url?] || false
+      )
+
+    new_path = ~p"/members?#{query_params}"
+    {:noreply, push_patch(socket, to: new_path, replace: true)}
+  end
+
   # Backward compatibility: tuple form delegates to map form
   def handle_info({:reset_all_filters, cycle_status_filter, boolean_filters}, socket) do
     handle_info(
@@ -502,6 +532,7 @@ defmodule MvWeb.MemberLive.Index do
       |> assign(:group_filters, Map.get(opts, :group_filters, %{}))
       |> assign(:fee_type_filters, Map.get(opts, :fee_type_filters, %{}))
       |> assign(:boolean_custom_field_filters, Map.get(opts, :boolean_filters, %{}))
+      |> assign(:date_filters, Map.get(opts, :date_filters, DateFilter.default()))
       |> load_members()
       |> update_selection_assigns()
 
@@ -632,6 +663,7 @@ defmodule MvWeb.MemberLive.Index do
       |> maybe_update_group_filters(params)
       |> maybe_update_fee_type_filters(params)
       |> maybe_update_boolean_filters(params)
+      |> maybe_update_date_filters(params)
       |> maybe_update_show_current_cycle(params)
       |> assign(:fields_in_url?, fields_in_url?)
       |> assign(:query, params["query"])
@@ -683,7 +715,8 @@ defmodule MvWeb.MemberLive.Index do
       socket.assigns.show_current_cycle,
       socket.assigns.boolean_custom_field_filters,
       socket.assigns.user_field_selection,
-      socket.assigns[:visible_custom_field_ids] || []
+      socket.assigns[:visible_custom_field_ids] || [],
+      socket.assigns[:date_filters]
     }
   end
 
@@ -783,7 +816,12 @@ defmodule MvWeb.MemberLive.Index do
     base_params = add_group_filters(base_params, opts.group_filters || %{})
     base_params = add_fee_type_filters(base_params, opts.fee_type_filters || %{})
     base_params = add_show_current_cycle(base_params, opts.show_current_cycle)
-    add_boolean_filters(base_params, opts.boolean_filters || %{})
+    base_params = add_boolean_filters(base_params, opts.boolean_filters || %{})
+    add_date_filters(base_params, opts.date_filters)
+  end
+
+  defp add_date_filters(params, date_filters) do
+    Map.merge(params, DateFilter.to_params(date_filters))
   end
 
   defp opts_for_query_params(socket, overrides \\ %{}) do
@@ -795,7 +833,8 @@ defmodule MvWeb.MemberLive.Index do
       group_filters: socket.assigns[:group_filters] || %{},
       show_current_cycle: socket.assigns.show_current_cycle,
       boolean_filters: socket.assigns.boolean_custom_field_filters || %{},
-      fee_type_filters: socket.assigns[:fee_type_filters] || %{}
+      fee_type_filters: socket.assigns[:fee_type_filters] || %{},
+      date_filters: socket.assigns.date_filters
     }
     |> Map.merge(overrides)
   end
@@ -941,26 +980,7 @@ defmodule MvWeb.MemberLive.Index do
       |> Ash.Query.new()
       |> Ash.Query.select(@overview_fields)
 
-    visible_custom_field_ids = socket.assigns[:visible_custom_field_ids] || []
-
-    boolean_custom_fields_map =
-      socket.assigns.boolean_custom_fields
-      |> Map.new(fn cf -> {to_string(cf.id), cf} end)
-
-    active_boolean_filter_ids =
-      socket.assigns.boolean_custom_field_filters
-      |> Map.keys()
-      |> Enum.filter(fn id_str ->
-        String.length(id_str) <= @max_uuid_length &&
-          match?({:ok, _}, Ecto.UUID.cast(id_str)) &&
-          Map.has_key?(boolean_custom_fields_map, id_str)
-      end)
-
-    ids_to_load =
-      (visible_custom_field_ids ++ active_boolean_filter_ids)
-      |> Enum.uniq()
-
-    query = load_custom_field_values(query, ids_to_load)
+    query = load_custom_field_values(query, compute_ids_to_load(socket))
 
     query = MembershipFeeStatus.load_cycles_for_members(query, socket.assigns.show_current_cycle)
 
@@ -984,6 +1004,13 @@ defmodule MvWeb.MemberLive.Index do
     query =
       apply_fee_type_filters(query, socket.assigns[:fee_type_filters], socket.assigns[:fee_types])
 
+    # Built-in date filters (join_date, exit_date) are pushed to the DB so
+    # excluded rows never reach the BEAM. The active_only default is part of
+    # this — fresh load returns only members without an exit_date or with an
+    # exit_date strictly in the future.
+    query =
+      DateFilter.apply_ash_filter(query, socket.assigns.date_filters)
+
     # Use ALL custom fields for sorting (not just show_in_overview subset)
     custom_fields_for_sort = socket.assigns.all_custom_fields
 
@@ -1003,21 +1030,7 @@ defmodule MvWeb.MemberLive.Index do
     # Custom field values are already filtered at the database level in load_custom_field_values/2
     # No need for in-memory filtering anymore
 
-    # Apply cycle status filter if set
-    members =
-      apply_cycle_status_filter(
-        members,
-        socket.assigns.cycle_status_filter,
-        socket.assigns.show_current_cycle
-      )
-
-    # Apply boolean custom field filters if set
-    members =
-      apply_boolean_custom_field_filters(
-        members,
-        socket.assigns.boolean_custom_field_filters,
-        socket.assigns.all_custom_fields
-      )
+    members = apply_in_memory_filters(members, socket)
 
     # Sort in memory if needed (custom fields, groups, group_count; computed fields are blocked)
     # Note: :groups is in computed_member_fields() but can be sorted in-memory, so we only block :membership_fee_status
@@ -1037,6 +1050,55 @@ defmodule MvWeb.MemberLive.Index do
     assign(socket, :members, members)
   end
 
+  # Collects every custom field UUID whose values must be loaded for a given
+  # render — visible columns plus any active boolean or date filter. Kept as a
+  # standalone helper so load_members/1 stays under the credo complexity bar.
+  defp compute_ids_to_load(socket) do
+    visible_custom_field_ids = socket.assigns[:visible_custom_field_ids] || []
+
+    boolean_custom_fields_map =
+      socket.assigns.boolean_custom_fields
+      |> Map.new(fn cf -> {to_string(cf.id), cf} end)
+
+    active_boolean_filter_ids =
+      socket.assigns.boolean_custom_field_filters
+      |> Map.keys()
+      |> Enum.filter(fn id_str ->
+        String.length(id_str) <= @max_uuid_length &&
+          match?({:ok, _}, Ecto.UUID.cast(id_str)) &&
+          Map.has_key?(boolean_custom_fields_map, id_str)
+      end)
+
+    date_custom_fields = socket.assigns[:date_custom_fields] || []
+
+    active_date_filter_ids =
+      DateFilter.active_custom_field_ids(
+        socket.assigns.date_filters,
+        date_custom_fields
+      )
+
+    (visible_custom_field_ids ++ active_boolean_filter_ids ++ active_date_filter_ids)
+    |> Enum.uniq()
+  end
+
+  # Post-DB filtering: cycle status, boolean custom fields, and custom date
+  # fields. Date custom fields are last so they see the already-narrowed list.
+  defp apply_in_memory_filters(members, socket) do
+    members
+    |> apply_cycle_status_filter(
+      socket.assigns.cycle_status_filter,
+      socket.assigns.show_current_cycle
+    )
+    |> apply_boolean_custom_field_filters(
+      socket.assigns.boolean_custom_field_filters,
+      socket.assigns.all_custom_fields
+    )
+    |> DateFilter.apply_in_memory(
+      socket.assigns.date_filters,
+      socket.assigns[:date_custom_fields] || []
+    )
+  end
+
   defp load_custom_field_values(query, []), do: query
 
   defp load_custom_field_values(query, custom_field_ids) do
@@ -1649,24 +1711,22 @@ defmodule MvWeb.MemberLive.Index do
 
   defp maybe_update_show_current_cycle(socket, _params), do: socket
 
+  # URL params are the source of truth for filter state on every navigation.
+  # When no date filter params are present, this falls through to the
+  # active_only default — exactly the spec behavior for fresh load (§1.1).
+  defp maybe_update_date_filters(socket, params) when is_map(params) do
+    date_custom_fields = socket.assigns[:date_custom_fields] || []
+    assign(socket, :date_filters, DateFilter.from_params(params, date_custom_fields))
+  end
+
+  defp maybe_update_date_filters(socket, _params), do: socket
+
   # -------------------------------------------------------------
   # Custom Field Value Helpers
   # -------------------------------------------------------------
 
   def get_custom_field_value(member, custom_field) do
-    case member.custom_field_values do
-      nil ->
-        nil
-
-      values when is_list(values) ->
-        Enum.find(values, fn cfv ->
-          cfv.custom_field_id == custom_field.id or
-            (match?(%{custom_field: %{id: _}}, cfv) && cfv.custom_field.id == custom_field.id)
-        end)
-
-      _ ->
-        nil
-    end
+    CustomFieldValueLookup.find_by_field(member, custom_field)
   end
 
   def get_boolean_custom_field_value(member, custom_field) do
@@ -1725,29 +1785,12 @@ defmodule MvWeb.MemberLive.Index do
   end
 
   defp matches_filter?(member, custom_field_id_str, filter_value) do
-    case find_custom_field_value_by_id(member, custom_field_id_str) do
+    case CustomFieldValueLookup.find_by_id(member, custom_field_id_str) do
       nil -> false
       cfv -> extract_boolean_value(cfv.value) == filter_value
     end
   end
 
-  defp find_custom_field_value_by_id(member, custom_field_id_str) do
-    case member.custom_field_values do
-      nil ->
-        nil
-
-      values when is_list(values) ->
-        Enum.find(values, fn cfv ->
-          to_string(cfv.custom_field_id) == custom_field_id_str or
-            (match?(%{custom_field: %{id: _}}, cfv) &&
-               to_string(cfv.custom_field.id) == custom_field_id_str)
-        end)
-
-      _ ->
-        nil
-    end
-  end
-
   def format_selected_member_emails(members, selected_members) do
     members
     |> Enum.filter(fn member ->

lib/mv_web/live/member_live/index/custom_field_value_lookup.ex

@@ -0,0 +1,61 @@
+defmodule MvWeb.MemberLive.Index.CustomFieldValueLookup do
+  @moduledoc """
+  Centralized lookup for a member's `custom_field_values` entry that matches
+  a given custom field.
+
+  Two callable shapes:
+
+    * `find_by_id/2` — match against a stringified UUID (used by the URL-param
+      driven date and boolean filter pipelines).
+    * `find_by_field/2` — match against a loaded `%CustomField{}` struct
+      (used by the table rendering / display path that already has the
+      field record at hand).
+
+  Both forms handle the two CFV layouts that appear on a loaded member:
+
+    * the direct foreign key — `%{custom_field_id: id, value: ...}`
+    * the nested loaded relation — `%{custom_field: %{id: id, ...}, value: ...}`
+
+  All non-loaded or empty containers (`nil`, `%Ash.NotLoaded{}`, empty list)
+  return `nil`.
+  """
+
+  @doc """
+  Returns the CFV entry whose custom field id, compared as a string, equals
+  `custom_field_id_str`. Returns `nil` when no entry matches or the
+  `custom_field_values` association is not a list.
+  """
+  @spec find_by_id(map(), String.t()) :: map() | nil
+  def find_by_id(member, custom_field_id_str) when is_binary(custom_field_id_str) do
+    member
+    |> Map.get(:custom_field_values)
+    |> find_in(fn cfv -> cfv_id_string(cfv) == custom_field_id_str end)
+  end
+
+  @doc """
+  Returns the CFV entry whose custom field id matches the given
+  `custom_field` struct's `:id`. The comparison is identity-based (not
+  stringified) because both sides are typically `Ash.UUID` binaries; falls
+  back to string comparison so atom-id callers still work.
+  """
+  @spec find_by_field(map(), map()) :: map() | nil
+  def find_by_field(member, %{id: field_id}) do
+    member
+    |> Map.get(:custom_field_values)
+    |> find_in(fn cfv -> cfv_id(cfv) == field_id end)
+  end
+
+  defp find_in(values, predicate) when is_list(values), do: Enum.find(values, predicate)
+  defp find_in(_other, _predicate), do: nil
+
+  defp cfv_id(%{custom_field_id: id}) when not is_nil(id), do: id
+  defp cfv_id(%{custom_field: %{id: id}}) when not is_nil(id), do: id
+  defp cfv_id(_), do: nil
+
+  defp cfv_id_string(cfv) do
+    case cfv_id(cfv) do
+      nil -> nil
+      id -> to_string(id)
+    end
+  end
+end

lib/mv_web/live/member_live/index/date_filter.ex

@@ -31,12 +31,25 @@ defmodule MvWeb.MemberLive.Index.DateFilter do
   require Ash.Query
   import Ash.Expr
 
+  alias MvWeb.MemberLive.Index.CustomFieldValueLookup
+  alias MvWeb.MemberLive.Index.FilterParams
+
   @join_date_from_param Mv.Constants.join_date_from_param()
   @join_date_to_param Mv.Constants.join_date_to_param()
   @exit_date_mode_param Mv.Constants.exit_date_mode_param()
   @exit_date_from_param Mv.Constants.exit_date_from_param()
   @exit_date_to_param Mv.Constants.exit_date_to_param()
   @custom_date_filter_prefix Mv.Constants.custom_date_filter_prefix()
+  @max_uuid_length Mv.Constants.max_uuid_length()
+
+  # An id stripped from a cdf_-prefixed param still has its `_from` / `_to`
+  # bound suffix attached when we first see it. The longest legal suffix is
+  # `_from` (5 chars), so the upper bound on a valid suffixed_id is
+  # @max_uuid_length + 5. Anything longer cannot map to a known custom date
+  # field and is rejected before further string work — matching the same
+  # DoS-protection contract enforced by the boolean / group / fee_type
+  # filter parsers in `MvWeb.MemberLive.Index`.
+  @max_suffixed_id_length @max_uuid_length + 5
 
   @doc """
   Returns the default date filter state used on fresh page load and after
@@ -139,15 +152,41 @@ defmodule MvWeb.MemberLive.Index.DateFilter do
 
   Today's date is captured via `Date.utc_today/0`; callers needing a frozen
   clock should wrap the call site, not this function.
+
+  The caller is expected to pass an `%Ash.Query{}` (typically built with
+  `Ash.Query.new/1` or via earlier filter chaining), matching the convention
+  used by the sibling `apply_search_filter/2`, `apply_group_filters/3`, and
+  `apply_fee_type_filters/3` helpers in `MvWeb.MemberLive.Index`.
   """
-  @spec apply_ash_filter(Ash.Query.t() | module(), map()) :: Ash.Query.t()
-  def apply_ash_filter(query_or_resource, filters) when is_map(filters) do
-    query_or_resource
-    |> Ash.Query.new()
-    |> apply_exit_date_filter(Map.get(filters, :exit_date, %{}))
-    |> apply_join_date_filter(Map.get(filters, :join_date, %{}))
+  @spec apply_ash_filter(Ash.Query.t(), map()) :: Ash.Query.t()
+  def apply_ash_filter(%Ash.Query{} = query, filters) when is_map(filters) do
+    exit_bounds = normalize_exit_bounds(Map.get(filters, :exit_date, %{}))
+    join_bounds = normalize_join_bounds(Map.get(filters, :join_date, %{}))
+
+    query
+    |> apply_exit_date_filter(exit_bounds)
+    |> apply_join_date_filter(join_bounds)
   end
 
+  # Defensive shape normalization: callers may supply maps where one bound key
+  # is absent entirely (not just nil). Pattern-match heads require both keys
+  # present, so we backfill nil here.
+  defp normalize_exit_bounds(bounds) when is_map(bounds) do
+    %{
+      mode: Map.get(bounds, :mode, :active_only),
+      from: Map.get(bounds, :from),
+      to: Map.get(bounds, :to)
+    }
+  end
+
+  defp normalize_exit_bounds(_), do: %{mode: :active_only, from: nil, to: nil}
+
+  defp normalize_join_bounds(bounds) when is_map(bounds) do
+    %{from: Map.get(bounds, :from), to: Map.get(bounds, :to)}
+  end
+
+  defp normalize_join_bounds(_), do: %{from: nil, to: nil}
+
   defp apply_exit_date_filter(query, %{mode: :all}), do: query
 
   defp apply_exit_date_filter(query, %{mode: :active_only}) do
@@ -231,6 +270,23 @@ defmodule MvWeb.MemberLive.Index.DateFilter do
     end
   end
 
+  @doc """
+  Returns the UUID string keys of `filters` that name an active (at-least-one-
+  bound-set) custom date field. The UUID must appear in `date_custom_fields`
+  (matched by `to_string(field.id)` and `value_type == :date`); other entries
+  are dropped.
+
+  Use this to compute which custom field values must be loaded so the
+  in-memory predicate (`apply_in_memory/3`) has the data it needs.
+  """
+  @spec active_custom_field_ids(map(), [map()]) :: [String.t()]
+  def active_custom_field_ids(filters, date_custom_fields)
+      when is_map(filters) and is_list(date_custom_fields) do
+    filters
+    |> active_custom_date_filters(date_custom_fields)
+    |> Enum.map(fn {id, _bounds} -> id end)
+  end
+
   defp matches_all_custom_dates?(member, active_filters) do
     Enum.all?(active_filters, fn {id, bounds} ->
       member_matches_custom_date?(member, id, bounds)
@@ -238,10 +294,7 @@ defmodule MvWeb.MemberLive.Index.DateFilter do
   end
 
   defp active_custom_date_filters(filters, date_custom_fields) do
-    valid_ids =
-      date_custom_fields
-      |> Enum.filter(&date_field?/1)
-      |> MapSet.new(&to_string(field_id(&1)))
+    valid_ids = valid_custom_date_field_ids(date_custom_fields)
 
     filters
     |> Enum.filter(fn
@@ -261,25 +314,11 @@ defmodule MvWeb.MemberLive.Index.DateFilter do
   end
 
   defp extract_member_date(member, custom_field_id) do
-    case Map.get(member, :custom_field_values) do
-      values when is_list(values) ->
-        values
-        |> Enum.find(&cfv_matches_id?(&1, custom_field_id))
-        |> extract_date_from_cfv()
-
-      _ ->
-        nil
-    end
+    member
+    |> CustomFieldValueLookup.find_by_id(custom_field_id)
+    |> extract_date_from_cfv()
   end
 
-  defp cfv_matches_id?(%{custom_field_id: cfid}, id) when not is_nil(cfid),
-    do: to_string(cfid) == id
-
-  defp cfv_matches_id?(%{custom_field: %{id: cfid}}, id) when not is_nil(cfid),
-    do: to_string(cfid) == id
-
-  defp cfv_matches_id?(_, _), do: false
-
   defp extract_date_from_cfv(nil), do: nil
 
   defp extract_date_from_cfv(%{value: value}), do: extract_date_value(value)
@@ -354,18 +393,16 @@ defmodule MvWeb.MemberLive.Index.DateFilter do
   defp parse_exit_date_mode(_), do: :active_only
 
   defp parse_custom_date_filters(params, date_custom_fields, base) do
-    valid_ids =
-      date_custom_fields
-      |> Enum.filter(&date_field?/1)
-      |> MapSet.new(&to_string(field_id(&1)))
-
-    prefix = @custom_date_filter_prefix
+    valid_ids = valid_custom_date_field_ids(date_custom_fields)
 
+    # FilterParams.parse_prefix_filters narrows the params map to the
+    # cdf_-prefixed subset once; the per-entry work below scales with the
+    # date filter count, not the full form-param map size.
     params
-    |> Enum.reduce(base, fn {key, value}, acc ->
-      with true <- is_binary(key),
-           true <- String.starts_with?(key, prefix),
-           {id, bound} <- split_custom_date_key(key, prefix),
+    |> FilterParams.parse_prefix_filters(@custom_date_filter_prefix, & &1)
+    |> Enum.reduce(base, fn {suffixed_id, value}, acc ->
+      with true <- bounded_id?(suffixed_id),
+           {id, bound} <- split_suffix(suffixed_id),
            true <- MapSet.member?(valid_ids, id),
            %Date{} = date <- parse_date(value) do
         update_custom_date_entry(acc, id, bound, date)
@@ -375,20 +412,35 @@ defmodule MvWeb.MemberLive.Index.DateFilter do
     end)
   end
 
+  # Reject any suffixed_id that could not possibly fit a UUID + bound suffix
+  # before doing further string work. This is the DoS-protection contract
+  # used by the boolean / group / fee_type filter parsers in
+  # `MvWeb.MemberLive.Index` (see `process_boolean_filter_param/5`,
+  # `add_group_filter_entry/4`, `add_fee_type_filter_entry/4`).
+  defp bounded_id?(suffixed_id) when is_binary(suffixed_id),
+    do: String.length(suffixed_id) <= @max_suffixed_id_length
+
+  defp bounded_id?(_), do: false
+
   defp date_field?(%{value_type: :date}), do: true
   defp date_field?(_), do: false
 
-  defp field_id(%{id: id}), do: id
-
-  defp split_custom_date_key(key, prefix) do
-    rest = String.slice(key, String.length(prefix), String.length(key))
+  # Single source of truth for the set of valid custom-date-field UUID strings.
+  # Used both when parsing URL params (to drop bogus UUIDs) and when computing
+  # which active filter entries actually correspond to a known date field.
+  defp valid_custom_date_field_ids(date_custom_fields) do
+    date_custom_fields
+    |> Enum.filter(&date_field?/1)
+    |> MapSet.new(&to_string(&1.id))
+  end
 
+  defp split_suffix(suffixed_id) do
     cond do
-      String.ends_with?(rest, "_from") ->
-        {String.slice(rest, 0, String.length(rest) - 5), :from}
+      String.ends_with?(suffixed_id, "_from") ->
+        {String.replace_suffix(suffixed_id, "_from", ""), :from}
 
-      String.ends_with?(rest, "_to") ->
-        {String.slice(rest, 0, String.length(rest) - 3), :to}
+      String.ends_with?(suffixed_id, "_to") ->
+        {String.replace_suffix(suffixed_id, "_to", ""), :to}
 
       true ->
         :error

lib/mv_web/live/member_live/index/filter_params.ex

@@ -1,8 +1,12 @@
 defmodule MvWeb.MemberLive.Index.FilterParams do
   @moduledoc """
-  Shared parsing helpers for member list filter URL/params (in/not_in style).
-  Used by MemberLive.Index and MemberFilterComponent to avoid duplication and recursion bugs.
+  Shared parsing helpers for member list filter URL/params.
+
+  Used by `MvWeb.MemberLive.Index`, `MvWeb.Components.MemberFilterComponent`,
+  and `MvWeb.MemberLive.Index.DateFilter` to avoid duplication and to keep
+  param-extraction logic in one place.
   """
+
   @doc """
   Parses a value for group or fee-type filter params.
   Returns `:in`, `:not_in`, or `nil`. Handles trimmed strings; no recursion.
@@ -19,4 +23,29 @@ defmodule MvWeb.MemberLive.Index.FilterParams do
   end
 
   def parse_in_not_in_value(_), do: nil
+
+  @doc """
+  Selects every `{key, value}` pair in `params` whose `key` is a binary that
+  starts with `prefix`, strips the prefix from the key, runs `parse_value_fn`
+  on the value, and accumulates the results into a map.
+
+  Non-binary keys are ignored. Exactly one occurrence of the prefix is
+  stripped (so a key like `"p_p_abc"` with prefix `"p_"` yields id `"p_abc"`).
+
+  The prefix-match filter is applied before the reduce so unrelated params
+  (e.g. `query`, `sort_field`, other-prefix filters) do not enter the
+  per-entry work — keeping the cost proportional to the matched subset on
+  every `phx-change` keystroke.
+  """
+  @spec parse_prefix_filters(map(), String.t(), (String.t() -> term())) ::
+          %{optional(String.t()) => term()}
+  def parse_prefix_filters(params, prefix, parse_value_fn)
+      when is_map(params) and is_binary(prefix) and is_function(parse_value_fn, 1) do
+    params
+    |> Enum.filter(fn {key, _} -> is_binary(key) and String.starts_with?(key, prefix) end)
+    |> Enum.reduce(%{}, fn {key, value}, acc ->
+      id = String.replace_prefix(key, prefix, "")
+      Map.put(acc, id, parse_value_fn.(value))
+    end)
+  end
 end

test/mv_web/live/member_live/date_filter_custom_field_test.exs

@@ -3,6 +3,9 @@ defmodule MvWeb.MemberLive.Index.DateFilterCustomFieldTest do
   Unit tests for `DateFilter.apply_in_memory/3` — the post-`Ash.read!`
   predicate that filters members by custom date field values stored as
   JSONB `Ash.Union` types in `custom_field_values`.
+
+  Integration coverage against a real database lives in the second module
+  in this file (DateFilterCustomFieldIntegrationTest).
   """
   use ExUnit.Case, async: true
 
@@ -208,3 +211,109 @@ defmodule MvWeb.MemberLive.Index.DateFilterCustomFieldTest do
     end
   end
 end
+
+defmodule MvWeb.MemberLive.Index.DateFilterCustomFieldIntegrationTest do
+  @moduledoc """
+  Integration tests for custom date field filtering on /members (§1.13, §1.14).
+
+  Creates a real `:date`-typed CustomField plus members with corresponding
+  CustomFieldValue rows, then asserts visibility through the LiveView with
+  `cdf_<uuid>_from` and `cdf_<uuid>_to` URL params.
+  """
+  # async: false because we mutate global custom_fields and custom_field_values tables.
+  use MvWeb.ConnCase, async: false
+  import Phoenix.LiveViewTest
+
+  alias Mv.Membership.{CustomField, CustomFieldValue}
+
+  setup do
+    system_actor = Mv.Helpers.SystemActor.get_system_actor()
+
+    {:ok, field} =
+      CustomField
+      |> Ash.Changeset.for_create(:create, %{
+        name: "Birthday-#{System.unique_integer([:positive])}",
+        value_type: :date,
+        show_in_overview: true
+      })
+      |> Ash.create(actor: system_actor)
+
+    {:ok, alice} =
+      Mv.Membership.create_member(
+        %{first_name: "Alice", last_name: "Anderson", email: "alice@example.com"},
+        actor: system_actor
+      )
+
+    {:ok, bob} =
+      Mv.Membership.create_member(
+        %{first_name: "Bob", last_name: "Brown", email: "bob@example.com"},
+        actor: system_actor
+      )
+
+    {:ok, carla} =
+      Mv.Membership.create_member(
+        %{first_name: "Carla", last_name: "Carter", email: "carla@example.com"},
+        actor: system_actor
+      )
+
+    {:ok, dan_no_value} =
+      Mv.Membership.create_member(
+        %{first_name: "Dan", last_name: "Dixon", email: "dan@example.com"},
+        actor: system_actor
+      )
+
+    create_cfv(system_actor, alice.id, field.id, ~D[2020-05-15])
+    create_cfv(system_actor, bob.id, field.id, ~D[2022-08-01])
+    create_cfv(system_actor, carla.id, field.id, ~D[2024-02-20])
+
+    %{
+      field: field,
+      alice: alice,
+      bob: bob,
+      carla: carla,
+      dan_no_value: dan_no_value
+    }
+  end
+
+  defp create_cfv(actor, member_id, custom_field_id, %Date{} = date) do
+    {:ok, cfv} =
+      CustomFieldValue
+      |> Ash.Changeset.for_create(:create, %{
+        member_id: member_id,
+        custom_field_id: custom_field_id,
+        value: %{"_union_type" => "date", "_union_value" => Date.to_iso8601(date)}
+      })
+      |> Ash.create(actor: actor, domain: Mv.Membership)
+
+    cfv
+  end
+
+  describe "custom date field URL filter" do
+    test "from-only includes members with value >= bound (§1.13)",
+         %{conn: conn, field: field, alice: alice, bob: bob, carla: carla} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?cdf_#{field.id}_from=2022-01-01")
+      refute html =~ alice.first_name
+      assert html =~ bob.first_name
+      assert html =~ carla.first_name
+    end
+
+    test "from+to applies inclusive range (§1.14)",
+         %{conn: conn, field: field, alice: alice, bob: bob, carla: carla} do
+      conn = conn_with_oidc_user(conn)
+
+      url = "/members?cdf_#{field.id}_from=2022-01-01&cdf_#{field.id}_to=2023-12-31"
+      {:ok, _view, html} = live(conn, url)
+      refute html =~ alice.first_name
+      assert html =~ bob.first_name
+      refute html =~ carla.first_name
+    end
+
+    test "excludes member with no value for the active custom date field (§1.13)",
+         %{conn: conn, field: field, dan_no_value: dan} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?cdf_#{field.id}_from=2000-01-01")
+      refute html =~ dan.first_name
+    end
+  end
+end

test/mv_web/live/member_live/date_filter_default_test.exs

@@ -22,3 +22,123 @@ defmodule MvWeb.MemberLive.Index.DateFilterDefaultTest do
     end
   end
 end
+
+defmodule MvWeb.MemberLive.Index.DateFilterDefaultIntegrationTest do
+  @moduledoc """
+  Integration tests for the default exit_date filter behavior on the member
+  overview page (§1.1, §1.2, §1.3, §1.4, §1.6 in the issue specs).
+
+  These exercise the full `mount/3` → `handle_params/3` → `load_members/1`
+  pipeline against a real database, asserting that the active-only default
+  is applied to a fresh page load and overridden when the URL says so.
+  """
+  # async: false because we mutate the global member table.
+  use MvWeb.ConnCase, async: false
+  import Phoenix.LiveViewTest
+
+  setup do
+    system_actor = Mv.Helpers.SystemActor.get_system_actor()
+    today = Date.utc_today()
+
+    {:ok, active_no_exit} =
+      Mv.Membership.create_member(
+        %{first_name: "Anna", last_name: "Active", email: "anna@example.com"},
+        actor: system_actor
+      )
+
+    {:ok, future_exit} =
+      Mv.Membership.create_member(
+        %{
+          first_name: "Felix",
+          last_name: "Future",
+          email: "felix@example.com",
+          join_date: Date.add(today, -365),
+          exit_date: Date.add(today, 30)
+        },
+        actor: system_actor
+      )
+
+    {:ok, exit_today} =
+      Mv.Membership.create_member(
+        %{
+          first_name: "Tina",
+          last_name: "Today",
+          email: "tina@example.com",
+          join_date: Date.add(today, -365),
+          exit_date: today
+        },
+        actor: system_actor
+      )
+
+    {:ok, past_exit} =
+      Mv.Membership.create_member(
+        %{
+          first_name: "Paula",
+          last_name: "Past",
+          email: "paula@example.com",
+          join_date: Date.add(today, -365),
+          exit_date: Date.add(today, -1)
+        },
+        actor: system_actor
+      )
+
+    %{
+      active_no_exit: active_no_exit,
+      future_exit: future_exit,
+      exit_today: exit_today,
+      past_exit: past_exit
+    }
+  end
+
+  describe "fresh load — no URL params" do
+    test "hides member with exit_date strictly before today (§1.1)", %{
+      conn: conn,
+      past_exit: past
+    } do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members")
+      refute html =~ past.first_name
+    end
+
+    test "hides member whose exit_date equals today (§1.4)", %{
+      conn: conn,
+      exit_today: exit_today
+    } do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members")
+      refute html =~ exit_today.first_name
+    end
+
+    test "shows member with no exit_date (§1.2)", %{conn: conn, active_no_exit: anna} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members")
+      assert html =~ anna.first_name
+    end
+
+    test "shows member with exit_date strictly in the future (§1.3)", %{
+      conn: conn,
+      future_exit: felix
+    } do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members")
+      assert html =~ felix.first_name
+    end
+  end
+
+  describe "URL with ed_mode=all overrides the default (§1.6)" do
+    test "shows former members when URL contains ed_mode=all", %{
+      conn: conn,
+      past_exit: past,
+      exit_today: today,
+      active_no_exit: anna,
+      future_exit: felix
+    } do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?ed_mode=all")
+      assert html =~ past.first_name
+      assert html =~ today.first_name
+      assert html =~ anna.first_name
+      assert html =~ felix.first_name
+    end
+  end
+end

test/mv_web/live/member_live/date_filter_test.exs

@@ -1,9 +1,8 @@
 defmodule MvWeb.MemberLive.Index.DateFilterTest do
   @moduledoc """
   Unit tests for DateFilter URL codec and pure helpers.
-  DB-level filtering and in-memory custom field filtering are covered in
-  separate integration tests (date_filter_default_test, date_filter_test,
-  date_filter_custom_field_test).
+  DB-level filtering against real members is covered by the integration
+  module below in this file.
   """
   use ExUnit.Case, async: true
 
@@ -201,7 +200,12 @@ defmodule MvWeb.MemberLive.Index.DateFilterTest do
 
     alias Mv.Membership.Member, as: MemberResource
 
-    defp base_query, do: MemberResource
+    # The production caller (`MvWeb.MemberLive.Index.load_members/1`) hands
+    # `apply_ash_filter/2` an already-built `%Ash.Query{}`, matching the
+    # convention of the sibling `apply_*_filters` helpers. The shape contract
+    # tests mirror that convention so they exercise the exact call shape used
+    # in production.
+    defp base_query, do: Ash.Query.new(MemberResource)
 
     test ":all mode and empty join_date is a no-op" do
       filters = %{
@@ -269,20 +273,102 @@ defmodule MvWeb.MemberLive.Index.DateFilterTest do
       refute is_nil(query.filter)
     end
 
-    test "accepts a non-resource Ash.Query as input" do
+    test "raises FunctionClauseError when caller passes a bare resource module" do
+      # The function now requires `%Ash.Query{}` — the production convention
+      # used by every sibling `apply_*_filters` helper in
+      # `MvWeb.MemberLive.Index`. A bare resource module is no longer accepted.
       filters = %{
         join_date: %{from: nil, to: nil},
-        exit_date: %{mode: :inactive_only, from: nil, to: nil}
+        exit_date: %{mode: :all, from: nil, to: nil}
       }
 
-      # Should also work when given a pre-built Ash.Query (not just a resource).
-      query =
-        MemberResource
-        |> Ash.Query.new()
-        |> DateFilter.apply_ash_filter(filters)
+      # Indirect through a variable so the compiler's static type analysis
+      # does not flag the deliberately invalid call shape we want to assert on.
+      bare_resource = Function.identity(MemberResource)
 
+      assert_raise FunctionClauseError, fn ->
+        DateFilter.apply_ash_filter(bare_resource, filters)
+      end
+    end
+
+    test "join_date map missing :to key still applies the from bound" do
+      # A caller-supplied map can omit one bound key entirely (not just set it
+      # to nil). The Ash filter must still be applied for the bound that is
+      # present.
+      filters = %{
+        join_date: %{from: ~D[2024-01-01]},
+        exit_date: %{mode: :all, from: nil, to: nil}
+      }
+
+      query = DateFilter.apply_ash_filter(base_query(), filters)
       refute is_nil(query.filter)
     end
+
+    test "join_date map missing :from key still applies the to bound" do
+      filters = %{
+        join_date: %{to: ~D[2024-12-31]},
+        exit_date: %{mode: :all, from: nil, to: nil}
+      }
+
+      query = DateFilter.apply_ash_filter(base_query(), filters)
+      refute is_nil(query.filter)
+    end
+
+    test ":custom exit_date with only :from key still applies the bound" do
+      filters = %{
+        join_date: %{from: nil, to: nil},
+        exit_date: %{mode: :custom, from: ~D[2024-01-01]}
+      }
+
+      query = DateFilter.apply_ash_filter(base_query(), filters)
+      refute is_nil(query.filter)
+    end
+
+    test ":custom exit_date with only :to key still applies the bound" do
+      filters = %{
+        join_date: %{from: nil, to: nil},
+        exit_date: %{mode: :custom, to: ~D[2024-12-31]}
+      }
+
+      query = DateFilter.apply_ash_filter(base_query(), filters)
+      refute is_nil(query.filter)
+    end
+  end
+
+  describe "active_custom_field_ids/2" do
+    test "returns UUID keys with at least one bound set whose UUID matches a date field" do
+      id_a = "11111111-1111-1111-1111-111111111111"
+      id_b = "22222222-2222-2222-2222-222222222222"
+      id_unknown = "33333333-3333-3333-3333-333333333333"
+
+      filters =
+        DateFilter.default()
+        |> Map.put(id_a, %{from: ~D[2024-01-01], to: nil})
+        |> Map.put(id_b, %{from: nil, to: nil})
+        |> Map.put(id_unknown, %{from: ~D[2024-06-01], to: nil})
+
+      ids =
+        DateFilter.active_custom_field_ids(filters, [
+          date_custom_field(id_a),
+          date_custom_field(id_b)
+        ])
+
+      assert ids == [id_a]
+    end
+
+    test "ignores non-binary keys (built-in atoms)" do
+      assert DateFilter.active_custom_field_ids(DateFilter.default(), []) == []
+    end
+
+    test "returns [] when no date custom fields are supplied" do
+      id_a = "11111111-1111-1111-1111-111111111111"
+
+      filters =
+        DateFilter.default()
+        |> Map.put(id_a, %{from: ~D[2024-01-01], to: nil})
+
+      assert DateFilter.active_custom_field_ids(filters, []) == []
+    end
   end
 
   describe "from_params/2 — custom date field entries" do
@@ -312,5 +398,231 @@ defmodule MvWeb.MemberLive.Index.DateFilterTest do
         other -> flunk("expected nil bound for malformed input, got #{inspect(other)}")
       end
     end
+
+    test "strips only the trailing _from / _to suffix, not internal substrings" do
+      # Construct an id that itself contains "_from" / "_to" — a quirky but
+      # legal MapSet key. Trailing-only suffix stripping must leave the
+      # internal substrings intact and recover the original id.
+      id_with_internal = "abc_from_xyz_to_def"
+
+      params = %{
+        "cdf_#{id_with_internal}_from" => "2024-06-01",
+        "cdf_#{id_with_internal}_to" => "2024-06-30"
+      }
+
+      filters =
+        DateFilter.from_params(params, [date_custom_field(id_with_internal)])
+
+      assert filters[id_with_internal] ==
+               %{from: ~D[2024-06-01], to: ~D[2024-06-30]}
+    end
+
+    test "drops cdf_-prefixed keys whose id exceeds the UUID length cap" do
+      # Matches the DoS-protection contract enforced by the sibling boolean,
+      # group, and fee_type filter parsers: an over-long id-portion (post
+      # prefix-strip, pre suffix-strip) is rejected without invoking the
+      # heavier String.replace_suffix / MapSet.member? path. The id we
+      # construct is well past `Mv.Constants.max_uuid_length()` (36).
+      known_id = "11111111-2222-3333-4444-555555555555"
+      over_long_id = String.duplicate("a", 200)
+
+      params = %{
+        "cdf_#{over_long_id}_from" => "2024-06-01",
+        "cdf_#{over_long_id}_to" => "2024-06-30"
+      }
+
+      filters = DateFilter.from_params(params, [date_custom_field(known_id)])
+
+      refute Map.has_key?(filters, over_long_id)
+      refute Map.has_key?(filters, "#{over_long_id}_from")
+      refute Map.has_key?(filters, "#{over_long_id}_to")
+    end
+  end
+end
+
+defmodule MvWeb.MemberLive.Index.DateFilterIntegrationTest do
+  @moduledoc """
+  Integration tests for the date filter URL → query → result-set pipeline.
+
+  Covers §1.7, §1.8, §1.9, §1.10, §1.11, §1.12, §1.15, §1.16, §1.17, §1.18,
+  §1.19. Custom date field filters are covered in the dedicated custom-field
+  integration test.
+  """
+  # async: false: mutates the global member table.
+  use MvWeb.ConnCase, async: false
+  import Phoenix.LiveViewTest
+
+  setup do
+    system_actor = Mv.Helpers.SystemActor.get_system_actor()
+    today = Date.utc_today()
+
+    {:ok, alice} =
+      Mv.Membership.create_member(
+        %{
+          first_name: "Alice",
+          last_name: "Anderson",
+          email: "alice@example.com",
+          join_date: ~D[2020-01-01]
+        },
+        actor: system_actor
+      )
+
+    {:ok, bob} =
+      Mv.Membership.create_member(
+        %{
+          first_name: "Bob",
+          last_name: "Brown",
+          email: "bob@example.com",
+          join_date: ~D[2022-06-15]
+        },
+        actor: system_actor
+      )
+
+    {:ok, carla} =
+      Mv.Membership.create_member(
+        %{
+          first_name: "Carla",
+          last_name: "Carter",
+          email: "carla@example.com",
+          join_date: ~D[2024-03-20]
+        },
+        actor: system_actor
+      )
+
+    {:ok, dan} =
+      Mv.Membership.create_member(
+        %{
+          first_name: "Dan",
+          last_name: "Dixon",
+          email: "dan@example.com"
+          # no join_date — should be excluded by any join_date range filter
+        },
+        actor: system_actor
+      )
+
+    {:ok, former} =
+      Mv.Membership.create_member(
+        %{
+          first_name: "Frida",
+          last_name: "Former",
+          email: "frida@example.com",
+          join_date: Date.add(today, -1000),
+          exit_date: Date.add(today, -10)
+        },
+        actor: system_actor
+      )
+
+    %{alice: alice, bob: bob, carla: carla, dan: dan, former: former, today: today}
+  end
+
+  describe "join_date filters" do
+    test "jd_from includes members with join_date >= bound; excludes nil (§1.7, §1.17)",
+         %{conn: conn, alice: alice, bob: bob, carla: carla, dan: dan} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?jd_from=2022-01-01")
+      refute html =~ alice.first_name
+      assert html =~ bob.first_name
+      assert html =~ carla.first_name
+      refute html =~ dan.first_name
+    end
+
+    test "jd_to excludes members with join_date > bound (§1.8)",
+         %{conn: conn, alice: alice, bob: bob, carla: carla, dan: dan} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?jd_to=2022-12-31")
+      assert html =~ alice.first_name
+      assert html =~ bob.first_name
+      refute html =~ carla.first_name
+      refute html =~ dan.first_name
+    end
+
+    test "jd_from and jd_to combine into an inclusive range (§1.9)",
+         %{conn: conn, alice: alice, bob: bob, carla: carla} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?jd_from=2022-01-01&jd_to=2023-12-31")
+      refute html =~ alice.first_name
+      assert html =~ bob.first_name
+      refute html =~ carla.first_name
+    end
+
+    test "no active filter imposes no constraint on the join_date field (§1.18)",
+         %{conn: conn, alice: alice, bob: bob, carla: carla, dan: dan} do
+      # Nil join_date members are still visible when no join_date filter is active.
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members")
+      assert html =~ alice.first_name
+      assert html =~ bob.first_name
+      assert html =~ carla.first_name
+      assert html =~ dan.first_name
+    end
+  end
+
+  describe "exit_date filters" do
+    test "ed_mode=inactive_only shows only former members (§1.10)",
+         %{conn: conn, alice: alice, former: former} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?ed_mode=inactive_only")
+      refute html =~ alice.first_name
+      assert html =~ former.first_name
+    end
+
+    test "ed_mode=all shows all members regardless of exit_date (§1.11)",
+         %{conn: conn, alice: alice, former: former} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?ed_mode=all")
+      assert html =~ alice.first_name
+      assert html =~ former.first_name
+    end
+
+    test "ed_mode=custom range hides members outside the range (§1.12)",
+         %{conn: conn, alice: alice, former: former, today: today} do
+      conn = conn_with_oidc_user(conn)
+      from = Date.add(today, -30) |> Date.to_iso8601()
+      to = Date.to_iso8601(today)
+
+      {:ok, _view, html} = live(conn, "/members?ed_mode=custom&ed_from=#{from}&ed_to=#{to}")
+      refute html =~ alice.first_name
+      assert html =~ former.first_name
+    end
+  end
+
+  describe "filter combination and URL persistence" do
+    test "join_date filter combined with the default (active-only) shows only active members in range (§1.15)",
+         %{conn: conn, alice: alice, bob: bob, former: former} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?jd_from=2020-01-01")
+      # Default active-only hides the former member even though they match join_date range.
+      refute html =~ former.first_name
+      assert html =~ alice.first_name
+      assert html =~ bob.first_name
+    end
+
+    test "date filter survives reload via URL params (§1.16)",
+         %{conn: conn, alice: alice, bob: bob, carla: carla} do
+      conn = conn_with_oidc_user(conn)
+      url = "/members?jd_from=2022-01-01&jd_to=2023-12-31"
+      {:ok, _view, html1} = live(conn, url)
+      {:ok, _view, html2} = live(conn, url)
+      # Same URL → same visible result set.
+      for member <- [alice, carla] do
+        refute html1 =~ member.first_name
+        refute html2 =~ member.first_name
+      end
+
+      assert html1 =~ bob.first_name
+      assert html2 =~ bob.first_name
+    end
+
+    test "malformed jd_from is silently ignored (§1.19)",
+         %{conn: conn, alice: alice, bob: bob, carla: carla, dan: dan} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, _view, html} = live(conn, "/members?jd_from=notadate")
+      # The filter is dropped, so default behavior (no join_date filter) applies
+      # and every member shows up.
+      assert html =~ alice.first_name
+      assert html =~ bob.first_name
+      assert html =~ carla.first_name
+      assert html =~ dan.first_name
+    end
   end
 end

test/mv_web/live/member_live/index/custom_field_value_lookup_test.exs

@@ -0,0 +1,89 @@
+defmodule MvWeb.MemberLive.Index.CustomFieldValueLookupTest do
+  @moduledoc """
+  Unit tests for the shared custom-field-value lookup helper.
+
+  The lookup must handle both shapes a CFV entry can take on a loaded member:
+
+    * `%{custom_field_id: id, value: ...}` — id present directly
+    * `%{custom_field: %{id: id, ...}, value: ...}` — id nested under loaded relation
+  """
+  use ExUnit.Case, async: true
+
+  alias MvWeb.MemberLive.Index.CustomFieldValueLookup
+
+  defp uuid, do: "11111111-2222-3333-4444-555555555555"
+
+  describe "find_by_id/2" do
+    test "matches when custom_field_id key is present" do
+      id = uuid()
+      cfv = %{custom_field_id: id, value: :anything}
+      member = %{custom_field_values: [cfv]}
+
+      assert CustomFieldValueLookup.find_by_id(member, id) == cfv
+    end
+
+    test "matches when nested custom_field relation is loaded" do
+      id = uuid()
+      cfv = %{custom_field: %{id: id, value_type: :date}, value: :anything}
+      member = %{custom_field_values: [cfv]}
+
+      assert CustomFieldValueLookup.find_by_id(member, id) == cfv
+    end
+
+    test "compares stringified ids — accepts atom or binary ids on the cfv side" do
+      id = uuid()
+      cfv = %{custom_field_id: id, value: :v}
+      member = %{custom_field_values: [cfv]}
+
+      # Same id, passed as binary
+      assert CustomFieldValueLookup.find_by_id(member, id) == cfv
+    end
+
+    test "returns nil when no entry has a matching id" do
+      member = %{
+        custom_field_values: [
+          %{custom_field_id: "11111111-1111-1111-1111-111111111111", value: 1}
+        ]
+      }
+
+      assert CustomFieldValueLookup.find_by_id(member, uuid()) == nil
+    end
+
+    test "returns nil when custom_field_values is nil" do
+      assert CustomFieldValueLookup.find_by_id(%{custom_field_values: nil}, uuid()) == nil
+    end
+
+    test "returns nil when custom_field_values is not loaded (Ash.NotLoaded)" do
+      member = %{custom_field_values: %Ash.NotLoaded{type: :relationship}}
+      assert CustomFieldValueLookup.find_by_id(member, uuid()) == nil
+    end
+
+    test "returns nil when custom_field_values is empty" do
+      assert CustomFieldValueLookup.find_by_id(%{custom_field_values: []}, uuid()) == nil
+    end
+  end
+
+  describe "find_by_field/2" do
+    test "matches a custom_field struct via its :id" do
+      id = uuid()
+      cfv = %{custom_field_id: id, value: :v}
+      member = %{custom_field_values: [cfv]}
+      custom_field = %{id: id, value_type: :boolean}
+
+      assert CustomFieldValueLookup.find_by_field(member, custom_field) == cfv
+    end
+
+    test "matches when only the nested custom_field is present" do
+      id = uuid()
+      cfv = %{custom_field: %{id: id}, value: :v}
+      member = %{custom_field_values: [cfv]}
+
+      assert CustomFieldValueLookup.find_by_field(member, %{id: id}) == cfv
+    end
+
+    test "returns nil when no entry matches" do
+      member = %{custom_field_values: [%{custom_field_id: "other", value: :v}]}
+      assert CustomFieldValueLookup.find_by_field(member, %{id: uuid()}) == nil
+    end
+  end
+end

test/mv_web/live/member_live/index/filter_params_test.exs

@@ -0,0 +1,85 @@
+defmodule MvWeb.MemberLive.Index.FilterParamsTest do
+  @moduledoc """
+  Unit tests for the shared filter-param parsers.
+  """
+  use ExUnit.Case, async: true
+
+  alias MvWeb.MemberLive.Index.FilterParams
+
+  describe "parse_prefix_filters/3" do
+    test "extracts only entries whose key starts with the prefix" do
+      params = %{
+        "group_abc" => "in",
+        "group_def" => "not_in",
+        "fee_type_xyz" => "in",
+        "unrelated" => "in",
+        "query" => "alice"
+      }
+
+      result = FilterParams.parse_prefix_filters(params, "group_", & &1)
+
+      assert result == %{"abc" => "in", "def" => "not_in"}
+    end
+
+    test "strips exactly one occurrence of the prefix, even when the rest starts with the prefix again" do
+      # Quirky but legal: a key like "p_p_abc" with prefix "p_" must produce id "p_abc".
+      params = %{"p_p_abc" => "v"}
+      result = FilterParams.parse_prefix_filters(params, "p_", & &1)
+      assert result == %{"p_abc" => "v"}
+    end
+
+    test "applies parse_value_fn to every value" do
+      params = %{"x_one" => "in", "x_two" => "not_in", "x_three" => "garbage"}
+
+      result =
+        FilterParams.parse_prefix_filters(
+          params,
+          "x_",
+          &FilterParams.parse_in_not_in_value/1
+        )
+
+      assert result == %{"one" => :in, "two" => :not_in, "three" => nil}
+    end
+
+    test "returns empty map when no key matches the prefix" do
+      params = %{"a" => "1", "b" => "2"}
+      assert FilterParams.parse_prefix_filters(params, "z_", & &1) == %{}
+    end
+
+    test "ignores non-binary keys" do
+      params = %{"x_a" => "1", :atom_key => "2", 123 => "3"}
+      result = FilterParams.parse_prefix_filters(params, "x_", & &1)
+      assert result == %{"a" => "1"}
+    end
+
+    test "returns empty map for empty input" do
+      assert FilterParams.parse_prefix_filters(%{}, "x_", & &1) == %{}
+    end
+  end
+
+  describe "parse_in_not_in_value/1" do
+    test "maps 'in' to :in" do
+      assert FilterParams.parse_in_not_in_value("in") == :in
+    end
+
+    test "maps 'not_in' to :not_in" do
+      assert FilterParams.parse_in_not_in_value("not_in") == :not_in
+    end
+
+    test "trims whitespace around recognized values" do
+      assert FilterParams.parse_in_not_in_value("  in  ") == :in
+      assert FilterParams.parse_in_not_in_value("\tnot_in\n") == :not_in
+    end
+
+    test "returns nil for unrecognized strings" do
+      assert FilterParams.parse_in_not_in_value("yes") == nil
+      assert FilterParams.parse_in_not_in_value("") == nil
+    end
+
+    test "returns nil for non-binary input" do
+      assert FilterParams.parse_in_not_in_value(nil) == nil
+      assert FilterParams.parse_in_not_in_value(:in) == nil
+      assert FilterParams.parse_in_not_in_value(123) == nil
+    end
+  end
+end