Fix h2_client:send_request/3

h2_client:send_request/3 does not check the return from
h2_connection:new_stream/1,2. When a new stream cannot be created,
for example, because the peer connection sets the maximum concurrent
streams to 1, h2_connection:new_stream/1,2 returns {error, 7}.

However, because h2_client:send_request/3 does not check this,
it returns {ok, {error, 7}} to the caller, which blows up when it next
tries to use a stream id of {error, 7}.

This commit corrects this so that h2_client:send_request/3 returns
either {ok, stream_id()} or {error, error_code()}.

This commit also refactors sync_request/3 to call send_request/3, and
adds or corrects some type specs (such as the one for
h2_connection:new_stream/1).

.gitignore

@@ -15,3 +15,4 @@ _build
 rebar3
 .rebar3
 log
+.*.sw?

src/h2_client.erl

@@ -114,21 +114,35 @@ start_ssl_upgrade_link(Host, Port, InitialMessage, SSLOptions) ->
 stop(Pid) ->
     h2_connection:stop(Pid).
 
+-spec sync_request(CliPid, Headers, Body) -> Result when
+      CliPid :: pid(), Headers :: hpack:headers(), Body :: binary(),
+      Result :: {ok, {hpack:headers(), iodata()}}
+                 | {error, error_code() | timeout}.
 sync_request(CliPid, Headers, Body) ->
-    StreamId = h2_connection:new_stream(CliPid),
-    h2_connection:send_headers(CliPid, StreamId, Headers),
-    h2_connection:send_body(CliPid,StreamId,Body),
-    receive
-        {'END_STREAM', StreamId} ->
-            h2_connection:get_response(CliPid, StreamId)
-    after 5000 ->
-        {error, timeout}
+    case send_request(CliPid, Headers, Body) of
+        {ok, StreamId} ->
+            receive
+                {'END_STREAM', StreamId} ->
+                    h2_connection:get_response(CliPid, StreamId)
+            after 5000 ->
+                      {error, timeout}
+            end;
+        Error ->
+            Error
     end.
+
+-spec send_request(CliPid, Headers, Body) -> Result when
+      CliPid :: pid(), Headers :: hpack:headers(), Body :: binary(),
+      Result :: {ok, stream_id()} | {error, error_code()}.
 send_request(CliPid, Headers, Body) ->
-    StreamId = h2_connection:new_stream(CliPid),
-    h2_connection:send_headers(CliPid, StreamId, Headers),
-    h2_connection:send_body(CliPid,StreamId,Body),
-    {ok, StreamId}.
+    case h2_connection:new_stream(CliPid) of
+        {error, _Code} = Err ->
+            Err;
+        StreamId ->
+            h2_connection:send_headers(CliPid, StreamId, Headers),
+            h2_connection:send_body(CliPid, StreamId, Body),
+            {ok, StreamId}
+    end.
 
 -spec get_response(pid(), stream_id()) ->
                           {ok, {hpack:header(), iodata()}}

src/h2_connection.erl

@@ -257,7 +257,7 @@ get_peercert(Pid) ->
 is_push(Pid) ->
     gen_fsm:sync_send_all_state_event(Pid, is_push).
 
--spec new_stream(pid()) -> stream_id().
+-spec new_stream(pid()) -> stream_id() | {error, error_code()}.
 new_stream(Pid) ->
     new_stream(Pid, self()).
 
@@ -274,7 +274,7 @@ send_promise(Pid, StreamId, NewStreamId, Headers) ->
 
 -spec get_response(pid(), stream_id()) ->
                           {ok, {hpack:headers(), iodata()}}
-                              | {error, term()}.
+                           | not_ready.
 get_response(Pid, StreamId) ->
     gen_fsm:sync_send_all_state_event(Pid, {get_response, StreamId}).