OPDATA-4087 track WS streamHandler connection attempts (#614)

* OPDATA-4087 track WS streamHandler connection attempts

* put back package.json

* lint fix

* review fix, add urlConfigFunctionParameters to pass state into implementing transport config.url()

* remove determineUrlChanges as it is not needed

* put back urlFromConfig varname

Author: mmcallister-cll

src/transports/websocket.ts

@@ -31,6 +31,14 @@ export class WebSocketClassProvider {
   }
 }
 
+/**
+ * Object used to pass partial websocket transport state into url config function.
+ */
+export interface WebSocketUrlConfigFunctionParameters {
+  /** Number of times streamHandler was called without a responsive connection */
+  streamHandlerInvocationsWithNoConnection: number
+}
+
 /**
  * Config object that is provided to the WebSocketTransport constructor.
  */
@@ -39,6 +47,7 @@ export interface WebSocketTransportConfig<T extends WebsocketTransportGenerics>
   url: (
     context: EndpointContext<T>,
     desiredSubs: TypeFromDefinition<T['Parameters']>[],
+    urlConfigFunctionParameters: WebSocketUrlConfigFunctionParameters,
   ) => Promise<string> | string
 
   /** Optional parameters used when establishing the WebSocket connection */
@@ -149,6 +158,7 @@ export class WebSocketTransport<
   currentUrl = ''
   lastMessageReceivedAt = 0
   connectionOpenedAt = 0
+  streamHandlerInvocationsWithNoConnection = 0
 
   constructor(private config: WebSocketTransportConfig<T>) {
     super()
@@ -328,11 +338,6 @@ export class WebSocketTransport<
       return
     }
 
-    // We want to check if the URL we calculate is different from the one currently connected.
-    // This is because some providers handle subscriptions on the URLs and not through messages.
-    const urlFromConfig = await this.config.url(context, subscriptions.desired)
-    const urlChanged = this.currentUrl !== urlFromConfig
-
     // We want to check that if we have a connection, it hasn't gone stale. That is,
     // since opening it, have we had any activity from the provider.
     const now = Date.now()
@@ -351,7 +356,27 @@ export class WebSocketTransport<
       timeSinceLastActivity: ${timeSinceLastActivity} |
       subscriptionUnresponsiveTtl: ${context.adapterSettings.WS_SUBSCRIPTION_UNRESPONSIVE_TTL} |
       connectionUnresponsive: ${connectionUnresponsive} |
-      `)
+    `)
+
+    // The var connectionUnresponsive checks whether the time since last activity on
+    // _any_ successful open connection (or 0 if we haven't had one yet) has exceeded
+    // WS_SUBSCRIPTION_UNRESPONSIVE_TTL. There is interplay with WS_SUBSCRIPTION_TTL
+    // to determine minimum TTL of an open connection given no explicit connection errors.
+    if (connectionUnresponsive) {
+      this.streamHandlerInvocationsWithNoConnection += 1
+      logger.trace(
+        `The connection is unresponsive, incremented streamHandlerIterationsWithNoConnection = ${this.streamHandlerInvocationsWithNoConnection}`,
+      )
+    }
+
+    // We want to check if the URL we calculate is different from the one currently connected.
+    // This is because some providers handle subscriptions on the URLs and not through messages.
+    // Subclasses may also implement alternate URL handling logic,
+    // eg: toggling through multiple possible URLs in case of failure.
+    const urlFromConfig = await this.config.url(context, subscriptions.desired, {
+      streamHandlerInvocationsWithNoConnection: this.streamHandlerInvocationsWithNoConnection,
+    })
+    const urlChanged = this.currentUrl !== urlFromConfig
 
     // Check if we should close the current connection
     if (!connectionClosed && (urlChanged || connectionUnresponsive)) {