Adopt Erlang/OTP 27

.github/workflows/erlang.yml

@@ -15,18 +15,13 @@ jobs:
 
     runs-on: ubuntu-22.04
 
-    strategy:
-      matrix:
-        otp: ['25', '26']
-        rebar: ['3.22']
-
     steps:
       - uses: actions/checkout@v3
       - uses: erlef/setup-beam@v1
         id: setup-beam
         with:
-          otp-version: ${{matrix.otp}}
-          rebar3-version: ${{matrix.rebar}}
+          version-type: strict
+          version-file: .tool-versions
       - name: Restore _build
         uses: actions/cache@v3
         with:

.tool-versions

@@ -0,0 +1,2 @@
+erlang 27.0
+rebar 3.23

rebar.config

@@ -3,7 +3,7 @@
 {erl_opts,
  [warn_unused_import, warn_export_vars, warnings_as_errors, verbose, report, debug_info]}.
 
-{minimum_otp_vsn, "21"}.
+{minimum_otp_vsn, "27"}.
 
 {profiles,
  [{test,

src/wpool_process.erl

@@ -46,9 +46,16 @@
 
 %% api
 -export([start_link/4, call/3, cast/2, send_request/2]).
+
+-ifdef(TEST).
+
+-export([get_state/1]).
+
+-endif.
+
 %% gen_server callbacks
 -export([init/1, terminate/2, code_change/3, handle_call/3, handle_cast/2, handle_info/2,
-         handle_continue/2, format_status/2]).
+         handle_continue/2, format_status/1]).
 
 %%%===================================================================
 %%% API
@@ -79,6 +86,14 @@ cast(Process, Cast) ->
 send_request(Name, Request) ->
     gen_server:send_request(Name, Request).
 
+-ifdef(TEST).
+
+-spec get_state(state()) -> term().
+get_state(#state{state = State}) ->
+    State.
+
+-endif.
+
 %%%===================================================================
 %%% init, terminate, code_change, info callbacks
 %%%===================================================================
@@ -177,19 +192,13 @@ handle_continue(Continue, State) ->
     end.
 
 %% @private
--spec format_status(normal | terminate, [[{_, _}] | state(), ...]) -> term().
-format_status(Opt, [PDict, State]) ->
-    case erlang:function_exported(State#state.mod, format_status, 2) of
+-spec format_status(gen_server:format_status()) -> gen_server:format_status().
+format_status(#{state := #state{mod = Mod}} = Status) ->
+    case erlang:function_exported(Mod, format_status, 1) of
         false ->
-            case Opt % This is copied from gen_server:format_status/4
-            of
-                terminate ->
-                    State#state.state;
-                normal ->
-                    [{data, [{"State", State#state.state}]}]
-            end;
+            Status;
         true ->
-            (State#state.mod):format_status(Opt, [PDict, State#state.state])
+            Mod:format_status(Status)
     end.
 
 %%%===================================================================

test/echo_server.erl

@@ -18,7 +18,7 @@
 
 %% gen_server callbacks
 -export([init/1, terminate/2, code_change/3, handle_call/3, handle_cast/2, handle_info/2,
-         handle_continue/2, format_status/2]).
+         handle_continue/2, format_status/1]).
 
 -dialyzer([no_behaviours]).
 
@@ -59,7 +59,6 @@ handle_call(Call, _From, _State) ->
 handle_continue(Continue, _State) ->
     Continue.
 
--spec format_status(normal | terminate, [[{_, _}] | State, ...]) ->
-                       {formatted_state, State}.
-format_status(_, [_PDict, State]) ->
-    {formatted_state, State}.
+-spec format_status(gen_server:format_status()) -> gen_server:format_status().
+format_status(State) ->
+    State.

test/wpool_process_SUITE.erl

@@ -175,24 +175,19 @@ continue(_Config) ->
 
 -spec format_status(config()) -> {comment, []}.
 format_status(_Config) ->
-    %% echo_server implements format_status/2
+    %% echo_server implements format_status/1
     {ok, Pid} = wpool_process:start_link(?MODULE, echo_server, {ok, state}, []),
-    %% therefore it returns {formatted_state, State} as its status
-    {status, Pid, {module, gen_server}, SItems} = sys:get_status(Pid),
-    [state] = [S || SItemList = [_ | _] <- SItems, {formatted_state, S} <- SItemList],
-    %% this code is actually what we use to retrieve the state in other tests
+    %% therefore it returns State as its status
     state = get_state(Pid),
     {comment, []}.
 
 -spec no_format_status(config()) -> {comment, []}.
 no_format_status(_Config) ->
-    %% crashy_server doesn't implement format_status/2
+    %% crashy_server doesn't implement format_status/1
     {ok, Pid} = wpool_process:start_link(?MODULE, crashy_server, state, []),
     %% therefore it uses the default format for the stauts (but with the status of
     %% the gen_server, not wpool_process)
-    {status, Pid, {module, gen_server}, SItems} = sys:get_status(Pid),
-    [state] =
-        [S || SItemList = [_ | _] <- SItems, {data, Data} <- SItemList, {"State", S} <- Data],
+    state = get_state(Pid),
     {comment, []}.
 
 -spec call(config()) -> {comment, []}.
@@ -329,13 +324,20 @@ complete_coverage(_Config) ->
     {comment, []}.
 
 %% @doc We can use this function in tests since echo_server implements
-%%      format_status/2 by returning the state as a tuple {formatted_state, S}.
+%%      format_status/1 by returning the status as a map S.
 %%      We can safely grab it from the result of sys:get_status/1
-%% @see gen_server:format_status/2
+%% @see gen_server:format_status/1
 %% @see sys:get_status/2
 get_state(Atom) when is_atom(Atom) ->
     get_state(whereis(Atom));
 get_state(Pid) ->
-    {status, Pid, {module, gen_server}, SItems} = sys:get_status(Pid),
-    [State] = [S || SItemList = [_ | _] <- SItems, {formatted_state, S} <- SItemList],
-    State.
+    {status, Pid, {module, gen_server}, [_PDict, _SysState, _Parent, _Dbg, Misc]} =
+        sys:get_status(Pid),
+    [State] =
+        lists:filtermap(fun ({data, [{"State", State}]}) ->
+                                {true, State};
+                            (_) ->
+                                false
+                        end,
+                        Misc),
+    wpool_process:get_state(State).