Use default shutdown time for gen_lsp_server

Erlang/OTP `supervisor` documentation says: [1]

> It is also allowed to set it to `infinity`, if the child process is a
> worker.
>
> Warning
>
> Be careful when setting the shutdown time to `infinity` when the child
> process is a worker. Because, in this situation, the termination of
> the supervision tree depends on the child process, it must be
> implemented in a safe way and its cleanup procedure must always
> return.

Therefore, the shutdown time of `gen_lsp_server` is changed from
`infinity` to default value, that is `5000` milliseconds for worker
processes.

Additionally, a sketch of the application supervision tree is added to
module header of `vscode_lsp_app` for easier understanding.

The `-behaviour` attributes are added to the corresponding modules, also
for easier understanding.

[1] https://www.erlang.org/doc/man/supervisor.html

apps/erlangbridge/src/gen_lsp_config_server.erl

@@ -1,13 +1,15 @@
 -module(gen_lsp_config_server).
-
 -behavior(gen_server).
--export([start_link/0]).
 
--export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
+%% API
+-export([start_link/0]).
 -export([standard_modules/0, bifs/0]).
 -export([update_config/2, root/0, tmpdir/0, codeLensEnabled/0, includePaths/0, linting/0,
-        verbose/0, autosave/0, proxy/0, search_files_exclude/0, search_exclude/0,
-        formatting_line_length/0, inlayHintsEnabled/0, verbose_is_include/1]).
+         verbose/0, autosave/0, proxy/0, search_files_exclude/0, search_exclude/0,
+         formatting_line_length/0, inlayHintsEnabled/0, verbose_is_include/1]).
+
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
 
 -include("lsp_log.hrl").
 -define(SERVER, ?MODULE).

apps/erlangbridge/src/gen_lsp_config_sup.erl

@@ -1,6 +1,11 @@
 -module(gen_lsp_config_sup).
+-behaviour(supervisor).
 
--export([init/1, start_link/0]).
+%% API
+-export([start_link/0]).
+
+%% Supervisor callbacks
+-export([init/1]).
 
 start_link() ->
     supervisor:start_link({local, ?MODULE}, ?MODULE, []).

apps/erlangbridge/src/gen_lsp_doc_server.erl

@@ -1,13 +1,17 @@
 -module(gen_lsp_doc_server).
-
 -behavior(gen_server).
+
+%% API
 -export([start_link/0]).
 
 -export([document_opened/2, document_changed/2, document_closed/1, opened_documents/0, get_document_contents/1, parse_document/1]).
 -export([project_file_added/1, project_file_changed/1, project_file_deleted/1]).
 -export([get_syntax_tree/1, get_dodged_syntax_tree/1, get_references/1, get_inlayhints/1]).
 -export([root_available/0, config_change/0, project_modules/0, get_module_file/1, get_module_files/1, get_build_dir/0, find_source_file/1]).
+
+%% gen_server callbacks
 -export([init/1,handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
+
 -include("./lsp_log.hrl").
 
 -define(SERVER, ?MODULE).

apps/erlangbridge/src/gen_lsp_doc_sup.erl

@@ -1,6 +1,11 @@
 -module(gen_lsp_doc_sup).
+-behaviour(supervisor).
 
--export([init/1, start_link/0]).
+%% API
+-export([start_link/0]).
+
+%% Supervisor callbacks
+-export([init/1]).
 
 start_link() ->
     supervisor:start_link({local, ?MODULE}, ?MODULE, []).

apps/erlangbridge/src/gen_lsp_help_server.erl

@@ -1,10 +1,12 @@
 -module(gen_lsp_help_server).
-
 -behavior(gen_server).
+
+%% API
 -export([start_link/0]).
+-export([get_help/2,get_help/5, render_help_body/3]).
 
+%% gen_server callbacks
 -export([init/1,handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
--export([get_help/2,get_help/5, render_help_body/3]).
 
 -define(SERVER, ?MODULE).
 

apps/erlangbridge/src/gen_lsp_help_sup.erl

@@ -1,6 +1,11 @@
 -module(gen_lsp_help_sup).
+-behaviour(supervisor).
 
--export([init/1, start_link/0]).
+%% API
+-export([start_link/0]).
+
+%% Supervisor callbacks
+-export([init/1]).
 
 start_link() ->
     supervisor:start_link({local, ?MODULE}, ?MODULE, []).

apps/erlangbridge/src/gen_lsp_server.erl

@@ -1,5 +1,4 @@
 -module(gen_lsp_server).
-
 -behavior(gen_server).
 
 %inspired from https://github.com/kevinlynx/erlang-tcpserver/blob/master/test/test.erl
@@ -9,12 +8,12 @@
 % http://learnyousomeerlang.com/buckets-of-sockets
 
 
-%API
+%% API
 -export([start_link/1, start_link/2]).
+-export([lsp_log/2, send_to_client/2]).
 
-%export for gen_server
+%% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
--export([lsp_log/2, send_to_client/2]).
 
 -define(SERVER, ?MODULE).
 %state

apps/erlangbridge/src/gen_lsp_sup.erl

@@ -1,6 +1,10 @@
 -module(gen_lsp_sup).
+-behaviour(supervisor).
 
+%% API
 -export([start_link/1]).
+
+%% Supervisor callbacks
 -export([init/1]).
 
 -define(TCP_OPTIONS, [binary, {packet, raw}, {active, once}, {reuseaddr, true}]).
@@ -17,8 +21,11 @@ start_link(Port) ->
 
 init(VsCodePort) ->
     {ok, LSock} = gen_tcp:listen(list_to_integer(VsCodePort), ?TCP_OPTIONS),
-    UserSpec = {gen_lsp_server, {gen_lsp_server, start_link, [list_to_integer(VsCodePort), LSock]},
-                            temporary, infinity, worker, [gen_lsp_server]},
+    UserSpec = #{id => gen_lsp_server,
+                 start => {gen_lsp_server, start_link, [list_to_integer(VsCodePort), LSock]},
+                 restart => temporary,
+                 modules => [gen_lsp_server],
+                 type => worker},
     StartSpecs = {{simple_one_for_one, 60, 3600}, [UserSpec]},
-    gen_tcp:send(LSock, <<"{}">>),    
+    gen_tcp:send(LSock, <<"{}">>),
     {ok, StartSpecs}.

apps/erlangbridge/src/vscode_lsp_app.erl

@@ -1,27 +1,62 @@
+%%%-------------------------------------------------------------------
+%%% @doc Erlang Language Server Process (LSP) for Visual Studio Code.
+%%%
+%%% Application supervision tree:
+%%%
+%%% ```
+%%% vscode_lsp_entry
+%%%  |
+%%%  | vscode_lsp [app.src]
+%%%  |
+%%% vscode_lsp_app [app]
+%%%  |
+%%% vscode_lsp_app_sup [sup]
+%%%  |
+%%%  +--gen_lsp_sup [sup]
+%%%  |   |
+%%%  |   +--gen_lsp_server [gen_server]
+%%%  |
+%%%  +--gen_lsp_doc_sup [sup]
+%%%  |   |  - (D)ETS document_contents
+%%%  |   |  - (D)ETS document_inlayhints
+%%%  |   |  - (D)ETS dodged_syntax_tree
+%%%  |   |  - ETS references
+%%%  |   |  - (D)ETS syntax_tree
+%%%  |   |
+%%%  |   +--gen_lsp_doc_server [gen_server]
+%%%  |
+%%%  +--gen_lsp_config_sup [sup]
+%%%  |   |
+%%%  |   +--gen_lsp_config_server [gen_server]
+%%%  |
+%%%  +--gen_lsp_help_sup [sup]
+%%%      |
+%%%      +--gen_lsp_help_server [gen_server]
+%%% '''
+%%%
+%%% @end
+%%%-------------------------------------------------------------------
 -module(vscode_lsp_app).
-
 -behavior(application).
 
+%% Application callbacks
 -export([start/2, stop/1]).
 
-
 get_port() ->
     case init:get_argument(vscode_port) of
-    {ok, [[P]]} -> P;
-    _ -> "0"
+        {ok, [[P]]} -> P;
+        _ -> "0"
     end.
-
 
 start(_Type, _Args) ->
     application:start(inets),
     %uncomment to monitor erlang processes
     %spawn(fun() -> observer:start() end),
     Port = get_port(),
     case vscode_lsp_app_sup:start_link(Port) of
-    {ok, Pid} ->
-        {ok, Pid};
-    _Any -> _Any        
+        {ok, Pid} -> {ok, Pid};
+        _Any      -> _Any
     end.
 
 stop(_State) ->
-    ok.
+    ok.

apps/erlangbridge/src/vscode_lsp_app_sup.erl

@@ -1,6 +1,11 @@
 -module(vscode_lsp_app_sup).
+-behaviour(supervisor).
 
--export([init/1, start_link/1, start_sup_socket/1, start_sup_doc/0, start_sup_config/0, start_sup_help/0, start_child/1]).
+%% API
+-export([start_link/1, start_sup_socket/1, start_sup_doc/0, start_sup_config/0, start_sup_help/0, start_child/1]).
+
+%% Supervisor callbacks
+-export([init/1]).
 
 start_link(VsCodePort) ->
     supervisor:start_link({local, ?MODULE}, ?MODULE, VsCodePort).
@@ -20,17 +25,12 @@ socket_spec(VsCodePort) ->
     modules => [gen_lsp_sup],
     type => supervisor}.
 
-start_sup_socket(VsCodePort) ->
-    supervisor:start_child({local, ?MODULE}, socket_spec(VsCodePort)).
-
 doc_spec() ->
     #{id => gen_lsp_doc_sup,
     start => {gen_lsp_doc_sup, start_link, []},
     restart => permanent,
     modules => [gen_lsp_doc_sup],
     type => supervisor}.
-%        {gen_lsp_doc_sup, {gen_lsp_doc_sup, start_link, []},
-%                        permanent, infinity, supervisor, [gen_lsp_doc_sup]}.
 
 config_spec() ->
     #{id => gen_lsp_config_sup,
@@ -46,6 +46,9 @@ help_spec() ->
     modules => [gen_lsp_help_sup],
     type => supervisor}.
 
+start_sup_socket(VsCodePort) ->
+    supervisor:start_child({local, ?MODULE}, socket_spec(VsCodePort)).
+
 start_sup_doc() ->
     supervisor:start_child(?MODULE, doc_spec()).