Pass on supported gun opts in connect()

README.md

@@ -65,6 +65,7 @@ The other way is send all that info as a parameter to `apns:connect/1` function
  , keyfile    => path()
  , timeout    => integer()
  , type       := type()
+ , gun        => gun:opts()
  }.
 ```
 
@@ -137,6 +138,13 @@ certfile => "priv/cert2.pem", keyfile => "priv/key2-noenc.pem", type => cert}).
 {ok,<0.132.0>}
 ```
 
+## Passing options specific to Gun
+
+The actual connection is handled by the [gun](https://github.com/ninenines/gun) library,
+which supports some options of its own. You can pass options specific to `gun` in
+the `connection` struct using `gun => GunOpts`. See the `gun` documentation for
+examples.
+
 ## Push Notifications over `Provider Certificate` connections
 
 In order to send Notifications over `Provider Certificate` connection we will use `apns:push_notification/3,4`.

elvis.config

@@ -9,6 +9,7 @@
         rules => [
             {elvis_style, line_length, #{limit => 100}}
           , {elvis_style, god_modules, #{limit => 25, ignore => [apns_connection]}}
+          , {elvis_style, dont_repeat_yourself, #{min_complexity => 12}}
           ]
        },
       #{dirs => ["."],

src/apns_connection.erl

@@ -68,6 +68,7 @@
 -type path()         :: string().
 -type notification() :: binary().
 -type type()         :: certdata | cert | token.
+-type http_opts()    :: #{ keepalive => non_neg_integer() }.
 -type keydata()      :: {'RSAPrivateKey' | 'DSAPrivateKey' | 'ECPrivateKey' |
                          'PrivateKeyInfo'
                         , binary()}.
@@ -87,6 +88,8 @@
                          , timeout    => integer()
                          , type       := type()
                          , proxy_info => proxy_info()
+                         , http_opts  => http_opts()
+                         , gun        => gun:opts()
                          }.
 
 -type state()        :: #{ connection      := connection()
@@ -227,25 +230,30 @@ open_origin(internal, _, #{connection := Connection} = StateData) ->
   Host = host(Connection),
   Port = port(Connection),
   TransportOpts = transport_opts(Connection),
+  Opts0 = #{ protocols      => [http2]
+           , transport_opts => TransportOpts
+           , retry          => 0
+           },
+  Opts = add_gun_opts(Connection, Opts0),
   {next_state, open_common, StateData,
     {next_event, internal, { Host
                            , Port
-                           , #{ protocols      => [http2]
-                              , transport_opts => TransportOpts
-                              , retry          => 0
-                              }}}}.
+                           , Opts}}}.
 
 -spec open_proxy(_, _, _) -> _.
 open_proxy(internal, _, StateData) ->
   #{connection := Connection} = StateData,
   #{type := connect, host := ProxyHost, port := ProxyPort} = proxy(Connection),
+  Opts0 = #{ protocols => [http]
+           , transport => tcp
+           , retry     => 0
+           },
+  Opts = add_gun_opts(Connection, Opts0),
   {next_state, open_common, StateData,
     {next_event, internal, { ProxyHost
                            , ProxyPort
-                           , #{ protocols => [http]
-                              , transport => tcp
-                              , retry     => 0
-                              }}}}.
+                           , Opts
+                           }}}.
 
 %% This function exists only to make Elvis happy.
 %% I do not think it makes things any easier to read.
@@ -492,3 +500,7 @@ backoff(N, Ceiling) ->
       NString = float_to_list(NextN, [{decimals, 0}]),
       list_to_integer(NString)
   end.
+
+add_gun_opts(Connection, Opts) ->
+  GunOpts = maps:get(gun, Connection, #{}),
+  maps:merge(GunOpts, Opts).

test/connection_SUITE.erl

@@ -10,6 +10,7 @@
         , certdata_keydata_connection/1
         , connect/1
         , connect_without_name/1
+        , connect_with_gun_params/1
         , gun_connection_lost/1
         , gun_connection_lost_timeout/1
         , gun_connection_killed/1
@@ -32,6 +33,7 @@ all() ->  [ default_connection
           , certdata_keydata_connection
           , connect
           , connect_without_name
+          , connect_with_gun_params
           , gun_connection_lost
           , gun_connection_lost_timeout
           , gun_connection_killed
@@ -122,6 +124,27 @@ connect_without_name(_Config) ->
   [_] = meck:unload(),
   ok.
 
+-spec connect_with_gun_params(config()) -> ok.
+connect_with_gun_params(_Config) ->
+  connect_with_gun_param(connect_timeout, 10000),
+  connect_with_gun_param(http_opts, #{keepalive => 10000}),
+  connect_with_gun_param(http2_opts, #{keepalive => 10000}),
+  connect_with_gun_param(retry_timeout, 10000),
+  connect_with_gun_param(trace, true),
+  connect_with_gun_param(transport, tls).
+
+-spec connect_with_gun_param(atom(), any()) -> ok.
+connect_with_gun_param(K, V) ->
+  ConnectionName = ?FUNCTION_NAME,
+  Connection = apns_connection:default_connection(cert, ConnectionName),
+  ok = mock_gun_open_param(K),
+  {ok, ServerPid} = apns:connect(Connection#{gun => #{K => V}}),
+  true = is_process_alive(ServerPid),
+  ok = close_connection(ServerPid),
+  [_] = meck:unload(),
+  ct:log("Gun param ~p => ~p passed correctly", [K, V]),
+  ok.
+
 -spec gun_connection_lost(config()) -> ok.
 gun_connection_lost(_Config) ->
   ok = mock_gun_open(),
@@ -394,10 +417,27 @@ test_function() ->
 -spec mock_gun_open() -> ok.
 mock_gun_open() ->
   meck:expect(gun, open, fun(_, _, _) ->
+    mimick_gun_open()
+  end).
+
+-spec mimick_gun_open() -> {ok, pid()}.
+mimick_gun_open() ->
     GunPid = spawn(fun test_function/0),
     self() ! {gun_up, GunPid, http2},
-    {ok, GunPid}
-  end).
+    {ok, GunPid}.
+
+-spec mock_gun_open_param(atom()) -> ok.
+mock_gun_open_param(Key) ->
+    meck:expect(
+      gun, open,
+      fun(_, _, Opts) ->
+              case maps:is_key(Key, Opts) of
+                  true ->
+                      mimick_gun_open();
+                  false ->
+                      error({missing_key, Key})
+              end
+      end).
 
 -spec mock_gun_post() -> ok.
 mock_gun_post() ->