fix: DH-20307: Throw errors when worker connection has been Disconnec… (#7362)

rc/0.40.x version of (#7175)

DH-20307: Don't attempt to reconnect when connections are explicitly
closed.

This PR is necessary to support fixes made in

[deephaven-ent/iris/#3518](deephaven-ent/iris#3518).
Specifically, there is a race condition where a created Core+ JS API
client can fail login and will continue to spam the server with login
attempts that will never succeed. That PR handles the client side piece
of this by explicitly disconnecting the client when this happens. The
server side fix is to stop attempting to reconnect if a connection is
explicitly closed.

### Testing
I have tested the 2 PRs together and have seen that this PR + the other
PR stops the rogue connection spamming. I have only seen change in
`connectToWorker` method of `WorkerConnection.java` actually get hit,
but I have also not observed any problems caused by it. (#DH-20307)

Author: bmingles

web/client-api/src/main/java/io/deephaven/web/client/api/CoreClient.java

@@ -122,7 +122,9 @@ public Promise<Void> login(@TsTypeRef(LoginCredentials.class) JsPropertyMap<Obje
         LazyPromise<Void> loginPromise = new LazyPromise<>();
         ideConnection.addEventListenerOneShot(
                 EventPair.of(QueryInfoConstants.EVENT_CONNECT, ignore -> loginPromise.succeed(null)),
-                EventPair.of(CoreClient.EVENT_RECONNECT_AUTH_FAILED, loginPromise::fail));
+                EventPair.of(CoreClient.EVENT_DISCONNECT, loginPromise::fail),
+                EventPair.of(CoreClient.EVENT_RECONNECT_AUTH_FAILED, loginPromise::fail),
+                EventPair.of(CoreClient.EVENT_REQUEST_FAILED, loginPromise::fail));
         Promise<Void> login = loginPromise.asPromise();
 
         if (alreadyRunning) {

web/client-api/src/main/java/io/deephaven/web/client/api/WorkerConnection.java

@@ -332,6 +332,12 @@ private void connectToWorker() {
 
                     return Promise.resolve((Object) null);
                 }, fail -> {
+                    // Connection was explicitly closed. We don't want to change
+                    // the status unless a `forceReconnect` is called.
+                    if (state == State.Disconnected) {
+                        return null;
+                    }
+
                     // this is non-recoverable, connection/auth/registration failed, but we'll let it start again when
                     // state changes
                     state = State.Failed;
@@ -909,8 +915,9 @@ private void notifyFieldsChangeListeners(JsVariableChanges update) {
 
     public Promise<Object> whenServerReady(String operationName) {
         switch (state) {
-            case Failed:
             case Disconnected:
+                throw new IllegalStateException("Can't " + operationName + " while connection is closed");
+            case Failed:
                 state = State.Reconnecting;
                 newSessionReconnect.initialConnection();
                 // deliberate fall-through
@@ -1389,8 +1396,9 @@ public void onOpen(BiConsumer<Void, String> callback) {
             case Connected:
                 LazyPromise.runLater(() -> callback.accept(null, null));
                 break;
-            case Failed:
             case Disconnected:
+                throw new IllegalStateException("Can't add onOpen callback when connection is closed");
+            case Failed:
                 state = State.Reconnecting;
                 newSessionReconnect.initialConnection();
                 // intentional fall-through