Add comments for different types of messages received by stream client

src/stream_client.erl

@@ -16,35 +16,40 @@ connect(Url, Headers, PostData, Callback) ->
             {error, {http_error, Reason}}
     end.
 
--spec handle_connection(term(), term()) -> ok | {error, reason}.
+-spec handle_connection(term(), term()) -> ok | {error, term()}.
 handle_connection(Callback, RequestId) ->
     receive
+        % stream opened
         {http, {RequestId, stream_start, _Headers}} ->
             handle_connection(Callback, RequestId);
 
+        % stream received data
         {http, {RequestId, stream, Data}} ->
             spawn(fun() ->
                 DecodedData = stream_client_util:decode(Data),
                 Callback(DecodedData)
             end),
             handle_connection(Callback, RequestId);
 
+        % stream closed
         {http, {RequestId, stream_end, _Headers}} ->
             {ok, RequestId};
 
+        % connected but received error cod
+        % 401 unauthorised - authentication credentials rejected
         {http, {RequestId, {{_, 401, _}, _Headers, _Body}}} ->
             {error, unauthorised};
 
+        % 406 not acceptable - invalid request to the search api
         {http, {RequestId, {{_, 406, _}, _Headers, Body}}} ->
             {error, {invalid_params, Body}};
 
+        % connection error
+        % may happen while connecting or after connected
         {http, {RequestId, {error, _Reason}}} ->
             {error, http_error};
 
+        % received terminate message
         terminate ->
-            {ok, RequestId};
-
-        Other ->
-            error_logger:info_msg("stream_client#handle_connection received unexpected message: ~p~n", [Other]),
-            handle_connection(Callback, RequestId)
+            {ok, RequestId}
     end.