chore: include line number in the undefined filter error message

Author: Cervajz

lib/solid/undefined_filter_error.ex

@@ -3,5 +3,9 @@ defmodule Solid.UndefinedFilterError do
   defexception [:filter, :loc]
 
   @impl true
-  def message(exception), do: "Undefined filter #{exception.filter}"
+  def message(exception) do
+    line = exception.loc.line
+    reason = "Undefined filter #{exception.filter}"
+    "#{line}: #{reason}"
+  end
 end

test/solid_test.exs

@@ -289,5 +289,20 @@ defmodule SolidTest do
                "user.properties.name"
              )
     end
+
+    test "undefined filter error message with line number" do
+      template = "{{ var1 | not_a_filter }}"
+
+      assert_raise Solid.RenderError,
+                   "1 error(s) found while rendering\n1: Undefined filter not_a_filter",
+                   fn ->
+                     template
+                     |> Solid.parse!()
+                     |> Solid.render!(%{"var1" => "value"},
+                       strict_filters: true,
+                       file_system: {TestFileSystem, nil}
+                     )
+                   end
+    end
   end
 end