improve: eliminate dialyzer warnings

Author: HJianBo

examples/active_n/recv_eprof.erl

@@ -53,7 +53,7 @@ listen(How, Port) ->
 
 accept(How, L) ->
     {ok, Sock} = gen_tcp:accept(L),
-    case How of
+    _ = case How of
         active_n ->
             inet:setopts(Sock, [{active, 100}]);
         async_recv -> ok

examples/client/echo_client.erl

@@ -62,7 +62,7 @@ loop(Num, Sock) ->
             io:format("Client ~w unexpected: ~p", [Num, Other])
     after
         Timeout ->
-            send(Num, Sock), loop(Num, Sock)
+            _ = send(Num, Sock), loop(Num, Sock)
     end.
 
 send(N, Sock) ->

examples/dtls_psk/dtls_psk_echo_server.erl

@@ -20,8 +20,10 @@
 
 -export([start_link/2, loop/2]).
 
+-dialyzer({nowarn_function, [start/1]}).
+
 start(Port) ->
-    [{ok, _} = application:ensure_all_started(App) || App <- [sasl, crypto, ssl, esockd]],
+    _ = [application:ensure_all_started(App) || App <- [sasl, crypto, ssl, esockd]],
     DtlsOpts = [{mode, binary}, {reuseaddr, true}] ++ psk_opts(),
     Opts = [{acceptors, 4}, {max_clients, 1000}, {dtls_options, DtlsOpts}],
     {ok, _} = esockd:open_dtls('echo/dtls', Port, Opts, {?MODULE, start_link, []}).

examples/plain/plain_echo_server.erl

@@ -49,7 +49,7 @@ recvloop(Sock) ->
         {ok, Data} ->
             {ok, Peername} = inet:peername(Sock),
             io:format("Data from ~s: ~s~n", [esockd:format(Peername), Data]),
-            gen_tcp:send(Sock, Data),
+            _ = gen_tcp:send(Sock, Data),
             recvloop(Sock);
         {error, Reason} ->
             io:format("TCP closed for ~s~n", [Reason]),

examples/tcp_window/tcp_window.erl

@@ -39,7 +39,7 @@ start(Port, How) when is_integer(Port) ->
                {shutdown, infinity},
                {max_connections, 100},
                {tcp_options, ?TCP_OPTIONS}],
-    esockd:open(tcp_block, Port, Options, {?MODULE, start_server, [How]}),
+    _ = esockd:open(tcp_block, Port, Options, {?MODULE, start_server, [How]}),
     start_client(Port).
 
 start_server(Transport, Sock, How) ->
@@ -91,14 +91,14 @@ send_loop(Transport, Sock, SendFun, Data, Count) ->
 start_client(Port) ->
     case gen_tcp:connect("127.0.0.1", Port, ?TCP_OPTIONS, 60000) of
         {ok, Sock} ->
-            inet:setopts(Sock, [{active, false}]),
+            _ = inet:setopts(Sock, [{active, false}]),
             client_loop(Sock, 0);
         {error, Reason} ->
             io:format("client failed to connect: ~p~n", [Reason])
     end.
 
 client_loop(Sock, I) ->
-    gen_tcp:send(Sock, crypto:strong_rand_bytes(1024*1024)),
+    _ = gen_tcp:send(Sock, crypto:strong_rand_bytes(1024*1024)),
     timer:sleep(1000),
     case gen_tcp:recv(Sock, 0) of
         {ok, Data} ->

rebar.config

@@ -36,7 +36,9 @@
 {cover_opts, [verbose]}.
 {cover_export_enabled, true}.
 
-{dialyzer, [{warnings, [unmatched_returns, error_handling, race_conditions]}]}.
+{dialyzer, [{warnings, [unmatched_returns,
+                        error_handling,
+                        race_conditions]}]}.
 
 {profiles,
     [{test,

src/esockd_dtls_acceptor.erl

@@ -86,7 +86,7 @@ accepting(internal, accept,
             %% Inc accepted stats.
             StatsFun({inc, 1}),
 
-            case TuneFun(Sock) of
+            _ = case TuneFun(Sock) of
                 {ok, Sock} ->
                     case esockd_connection_sup:start_connection(ConnSup, Sock, UpgradeFuns) of
                         {ok, _Pid} -> ok;