@spec collect_errors(filtr_result :: map()) :: map() | nil

Collects all errors from a Filtr result map into a structured error map.

This function is primarily useful when using :strict error mode, where errors are returned as {:error, [...]} tuples in the result map rather than being replaced with default values (:fallback) or raising exceptions (:raise).

This function traverses the result map returned by Filtr.run/2 or Filtr.run/3 and extracts all error tuples, organizing them into a hierarchical structure that mirrors the original schema structure.

Examples

iex> result = %{name: {:error, "required"}, age: 25}
iex> Filtr.collect_errors(result)
%{name: ["required"]}


iex> result = %{name: "John", age: 25}
iex> Filtr.collect_errors(result)
nil

iex> result = %{
...>   user: %{
...>     name: {:error, "required"},
...>     age: 25
...>   }
...> }
iex> Filtr.collect_errors(result)
%{user: %{name: ["required"]}}

iex> result = %{tags: ["valid", {:error, "too short"}, "another"]}
iex> Filtr.collect_errors(result)
%{tags: %{1 => ["too short"]}}

iex> result = %{
...>   users: [
...>     %{id: 1, name: "john"},
...>     %{id: 2, name: {:error, "required"}}
...>   ]
...> }
iex> Filtr.collect_errors(result)
%{users: %{1 => %{name: ["required"]}}}