Don't show signatures on module attributes

lib/livebook/intellisense/signature_matcher.ex

@@ -168,6 +168,10 @@ defmodule Livebook.Intellisense.SignatureMatcher do
     find_cursor_call(right, {nil, :pipe})
   end
 
+  defp find_cursor_call({:@, _, [{attr, _, [arg]}]}, _acc) when is_atom(attr) do
+    find_cursor_call(arg, {nil, :none})
+  end
+
   defp find_cursor_call({left, _, right} = node, {_, pipe_info} = acc) when is_list(right) do
     if is_atom(left) and
          (Macro.operator?(left, length(right)) or

test/livebook/intellisense_test.exs

@@ -1464,5 +1464,34 @@ defmodule Livebook.IntellisenseTest do
                ]
              } = Intellisense.get_signature_items("Enum.concat([1, 2], ", binding, env)
     end
+
+    test "does not return any signatures for module attributes" do
+      {binding, env} = eval(do: nil)
+
+      assert nil == Intellisense.get_signature_items("@length(", binding, env)
+    end
+
+    test "does not returns signatures for calls in attribute value" do
+      {binding, env} = eval(do: nil)
+
+      assert %{
+               active_argument: 0,
+               signature_items: [
+                 %{
+                   arguments: ["list"],
+                   documentation: """
+                   Returns the length of `list`.
+
+                   ---
+
+                   ```
+                   @spec length(list()) :: non_neg_integer()
+                   ```\
+                   """,
+                   signature: "length(list)"
+                 }
+               ]
+             } = Intellisense.get_signature_items("@attr length(", binding, env)
+    end
   end
 end