fix: get_from_cookie now correctly handles list return from get_req_header

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

@@ -69,17 +69,17 @@ defmodule MvWeb.MemberLive.Index.FieldSelection do
   Returns a map of field names (strings) to boolean visibility values.
   Returns empty map if no cookie is present.
 
-  Note: This function requires the connection to have cookies parsed.
-  In LiveView, cookies are typically accessed via get_connect_info.
+  Note: This function parses the raw Cookie header. In LiveView, cookies
+  are typically accessed via get_connect_info.
   """
   @spec get_from_cookie(Plug.Conn.t()) :: %{String.t() => boolean()}
   def get_from_cookie(conn) do
+    # get_req_header always returns a list ([] if no header, [value] if present)
     case Plug.Conn.get_req_header(conn, "cookie") do
-      nil ->
+      [] ->
         %{}
 
-      cookie_header ->
-        # Parse cookies manually from header
+      [cookie_header | _rest] ->
         cookies = parse_cookie_header(cookie_header)
 
         case Map.get(cookies, @cookie_name) do

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

@@ -93,7 +93,15 @@ defmodule MvWeb.MemberLive.Index.FieldSelectionTest do
   end
 
   describe "get_from_cookie/1" do
-    test "returns empty map when cookie is missing" do
+    test "returns empty map when cookie header is missing" do
+      conn = %Plug.Conn{}
+
+      result = FieldSelection.get_from_cookie(conn)
+
+      assert result == %{}
+    end
+
+    test "returns empty map when cookie is empty string" do
       conn = Plug.Conn.put_req_header(%Plug.Conn{}, "cookie", "")
 
       result = FieldSelection.get_from_cookie(conn)
@@ -101,6 +109,17 @@ defmodule MvWeb.MemberLive.Index.FieldSelectionTest do
       assert result == %{}
     end
 
+    test "parses valid JSON from cookie" do
+      selection = %{"first_name" => true, "email" => false}
+      cookie_value = selection |> Jason.encode!() |> URI.encode()
+      cookie_header = "member_field_selection=#{cookie_value}"
+      conn = %Plug.Conn{} |> Plug.Conn.put_req_header("cookie", cookie_header)
+
+      result = FieldSelection.get_from_cookie(conn)
+
+      assert result == selection
+    end
+
     test "handles invalid JSON in cookie gracefully" do
       cookie_value = URI.encode("invalid{[")
       cookie_header = "member_field_selection=#{cookie_value}"
@@ -110,6 +129,17 @@ defmodule MvWeb.MemberLive.Index.FieldSelectionTest do
 
       assert result == %{}
     end
+
+    test "handles cookie with other values" do
+      selection = %{"street" => true}
+      cookie_value = selection |> Jason.encode!() |> URI.encode()
+      cookie_header = "other_cookie=value; member_field_selection=#{cookie_value}; another=test"
+      conn = %Plug.Conn{} |> Plug.Conn.put_req_header("cookie", cookie_header)
+
+      result = FieldSelection.get_from_cookie(conn)
+
+      assert result == selection
+    end
   end
 
   describe "save_to_cookie/2" do