test(coap): cover the params optional logic to create connection

apps/emqx_gateway_coap/src/emqx_coap_channel.erl

@@ -486,23 +486,21 @@ enrich_conninfo(
         conninfo = ConnInfo
     }
 ) ->
-    ClientId =
-        case maps:get(<<"clientid">>, Queries, undefined) of
-            undefined ->
-                emqx_gateway_utils:random_clientid(coap);
-            ClientId0 ->
-                ClientId0
-        end,
-    Interval = maps:get(interval, emqx_keepalive:info(KeepAlive)),
-    NConnInfo = ConnInfo#{
-        clientid => ClientId,
-        proto_name => <<"CoAP">>,
-        proto_ver => <<"1">>,
-        clean_start => true,
-        keepalive => Interval,
-        expiry_interval => 0
-    },
-    {ok, Channel#channel{conninfo = NConnInfo}}.
+    case Queries of
+        #{<<"clientid">> := ClientId} ->
+            Interval = maps:get(interval, emqx_keepalive:info(KeepAlive)),
+            NConnInfo = ConnInfo#{
+                clientid => ClientId,
+                proto_name => <<"CoAP">>,
+                proto_ver => <<"1">>,
+                clean_start => true,
+                keepalive => Interval,
+                expiry_interval => 0
+            },
+            {ok, Channel#channel{conninfo = NConnInfo}};
+        _ ->
+            {error, "clientid is required", Channel}
+    end.
 
 enrich_clientinfo(
     {Queries, Msg},

apps/emqx_gateway_coap/test/emqx_coap_SUITE.erl

@@ -133,6 +133,42 @@ t_connection(_) ->
     end,
     do(Action).
 
+t_connection_optional_params(_) ->
+    UsernamePasswordAreOptional =
+        fun(Channel) ->
+            URI =
+                ?MQTT_PREFIX ++
+                    "/connection?clientid=client1",
+            Req = make_req(post),
+            {ok, created, Data} = do_request(Channel, URI, Req),
+            #coap_content{payload = Token0} = Data,
+            Token = binary_to_list(Token0),
+
+            timer:sleep(100),
+            ?assertNotEqual(
+                [],
+                emqx_gateway_cm_registry:lookup_channels(coap, <<"client1">>)
+            ),
+
+            disconnection(Channel, Token),
+
+            timer:sleep(100),
+            ?assertEqual(
+                [],
+                emqx_gateway_cm_registry:lookup_channels(coap, <<"client1">>)
+            )
+        end,
+    ClientIdIsRequired =
+        fun(Channel) ->
+            URI =
+                ?MQTT_PREFIX ++
+                    "/connection",
+            Req = make_req(post),
+            {error, bad_request, _} = do_request(Channel, URI, Req)
+        end,
+    do(UsernamePasswordAreOptional),
+    do(ClientIdIsRequired).
+
 t_connection_with_authn_failed(_) ->
     ChId = {{127, 0, 0, 1}, 5683},
     {ok, Sock} = er_coap_udp_socket:start_link(),

apps/emqx_gateway_exproto/src/emqx_exproto_channel.erl

@@ -782,7 +782,7 @@ enrich_clientinfo(InClientInfo = #{proto_name := ProtoName}, ClientInfo) ->
 default_conninfo(ConnInfo) ->
     ConnInfo#{
         clean_start => true,
-        clientid => anonymous_clientid(),
+        clientid => emqx_gateway_utils:random_clientid(exproto),
         username => undefined,
         conn_props => #{},
         connected => true,
@@ -822,6 +822,3 @@ proto_name_to_protocol(<<>>) ->
     exproto;
 proto_name_to_protocol(ProtoName) when is_binary(ProtoName) ->
     binary_to_atom(ProtoName).
-
-anonymous_clientid() ->
-    iolist_to_binary(["exproto-", emqx_utils:gen_id()]).