Fix typespec with (...) -> any() (#1980)

Closes #1974

Author: josevalim

lib/ex_doc/language/erlang.ex

@@ -546,9 +546,14 @@ defmodule ExDoc.Language.Erlang do
             {op, _, [int]}, acc when is_integer(int) and op in [:+, :-] ->
               {nil, acc}
 
-            # fun() (spec_to_quoted expands it to (... -> any())
-            {:->, _, [[{name, _, _}], {:any, _, _}]}, acc when name == :... ->
-              {nil, acc}
+            # fun() (spec_to_quoted expands it to (... -> any() in Elixir v1.17 and earlier)
+            # TODO: Remove me when we require Elixir v1.18+
+            {:->, _, [[{name, _, _}], {:any, _, _}]} = node, acc when name == :... ->
+              if Version.match?(System.version(), ">= 1.18.0-rc") do
+                {node, acc}
+              else
+                {nil, acc}
+              end
 
             # record{type :: remote:type/arity}
             {:field_type, _, [name, {{:., _, [r_mod, r_type]}, _, args}]}, acc ->
@@ -588,7 +593,7 @@ defmodule ExDoc.Language.Erlang do
       end
       |> Enum.concat()
 
-    put(acc)
+    put_stack(acc)
 
     # Drop and re-add type name (it, the first element in acc, is dropped there too)
     #
@@ -614,16 +619,21 @@ defmodule ExDoc.Language.Erlang do
   defp replace(formatted, acc, config) do
     String.replace(formatted, Enum.map(acc, &"#{elem(&1, 0)}("), fn string ->
       string = String.trim_trailing(string, "(")
-      {other, ref} = pop()
-
-      if string != other do
-        Autolink.maybe_warn(
-          config,
-          "internal inconsistency, please submit bug: #{inspect(string)} != #{inspect(other)}",
-          nil,
-          nil
-        )
-      end
+
+      ref =
+        case get_stack() do
+          [{^string, ref} | tail] ->
+            put_stack(tail)
+            ref
+
+          _ ->
+            Autolink.maybe_warn(
+              config,
+              "internal inconsistency when processing #{inspect(formatted)}",
+              nil,
+              nil
+            )
+        end
 
       what =
         case config.current_kfa do
@@ -691,16 +701,16 @@ defmodule ExDoc.Language.Erlang do
     end)
   end
 
-  defp put(items) do
+  defp put_stack(items) do
     Process.put({__MODULE__, :stack}, items)
   end
 
-  defp pop() do
-    [head | tail] = Process.get({__MODULE__, :stack})
-    put(tail)
-    head
+  defp get_stack() do
+    Process.get({__MODULE__, :stack})
   end
 
+  defp pp(:fun), do: "fun"
+
   defp pp(name) when is_atom(name) do
     :io_lib.format("~p", [name]) |> IO.iodata_to_binary()
   end

test/ex_doc/language/erlang_test.exs

@@ -806,6 +806,12 @@ defmodule ExDoc.Language.ErlangTest do
     test "function - any arity", c do
       assert autolink_spec(~s"-spec foo() -> fun((...) -> t()) | erlang_bar:t().", c) ==
                ~s[foo() -> fun((...) -> <a href="#t:t/0">t</a>()) | <a href="erlang_bar.html#t:t/0">erlang_bar:t</a>().]
+
+      if Version.match?(System.version(), ">= 1.18.0-rc") do
+        assert autolink_spec(~s"-type foo() :: fun((...) -> any()) | [any()].", c) ==
+                 "foo() :: fun((...) -> <a href=\"https://www.erlang.org/doc/apps/erts/erlang.html#t:any/0\">any</a>()) | " <>
+                   "[<a href=\"https://www.erlang.org/doc/apps/erts/erlang.html#t:any/0\">any</a>()]."
+      end
     end
 
     test "local type", c do