feat(events): client conformance scenarios (#540)

examples/clients/typescript/events-broken-clients.ts

@@ -0,0 +1,27 @@
+/**
+ * Deliberately broken Events clients for the negative tests in
+ * src/scenarios/client/events/events.test.ts. Each one is the conformant
+ * client from events-client.ts with exactly one behaviour switched off, so a
+ * flipped check names the rule it caught.
+ */
+
+import {
+  CONFORMANT,
+  EventsClientOptions,
+  makeEventsClient
+} from './events-client.js';
+
+function broken(change: Partial<EventsClientOptions>) {
+  return makeEventsClient({ ...CONFORMANT, ...change });
+}
+
+export const ignoresExtensionGate = broken({ gateOnExtension: false });
+export const noDrainOnHasMore = broken({ drainOnHasMore: false });
+export const ignoresNextPollMs = broken({ respectNextPollMs: false });
+export const noPollFloor = broken({ pollFloorMs: 0 });
+export const dropsTruncatedCursor = broken({ persistTruncatedCursor: false });
+export const replaysNullCursor = broken({ replayNullCursor: true });
+export const failsOnAbsentCursor = broken({ tolerateAbsentCursor: false });
+export const ignoresListChanged = broken({ relistOnListChanged: false });
+export const refreshesAfterExpiry = broken({ refreshBeforeExpiry: false });
+export const neverReconnects = broken({ reconnectDeadStream: false });