Preserve chat scroll-away after delayed history

2026-06-28 19:10:12 +07:00
parent 96573d0bcc
commit 4968969c87
6 changed files with 494 additions and 8 deletions
@@ -0,0 +1,120 @@
+import type { Page } from "@playwright/test";
+import { daemonWsRoutePattern } from "./daemon-port";
+
+type WebSocketMessage = string | Buffer;
+
+interface CreatedAgentTimelineGate {
+  release(): void;
+  waitForCreatedAgent(): Promise<string>;
+  waitForDelayedResponse(): Promise<void>;
+  waitForForwardedResponse(): Promise<void>;
+}
+
+function parseWebSocketJson(message: WebSocketMessage): unknown {
+  const rawMessage = typeof message === "string" ? message : message.toString("utf8");
+  try {
+    return JSON.parse(rawMessage);
+  } catch {
+    return null;
+  }
+}
+
+function getSessionMessage(message: WebSocketMessage): Record<string, unknown> | null {
+  const envelope = parseWebSocketJson(message);
+  if (!envelope || typeof envelope !== "object") {
+    return null;
+  }
+  const maybeEnvelope = envelope as { type?: unknown; message?: unknown };
+  if (maybeEnvelope.type !== "session" || !maybeEnvelope.message) {
+    return null;
+  }
+  if (typeof maybeEnvelope.message !== "object") {
+    return null;
+  }
+  return maybeEnvelope.message as Record<string, unknown>;
+}
+
+function getPayload(message: Record<string, unknown>): Record<string, unknown> | null {
+  return message.payload && typeof message.payload === "object"
+    ? (message.payload as Record<string, unknown>)
+    : null;
+}
+
+export async function delayCreatedAgentInitialTailResponse(
+  page: Page,
+): Promise<CreatedAgentTimelineGate> {
+  let createdAgentId: string | null = null;
+  let releaseRequested = false;
+  let delayedResponseSeen = false;
+  const delayedForwards: Array<() => void> = [];
+  let resolveCreatedAgent: ((agentId: string) => void) | null = null;
+  let resolveDelayedResponse: (() => void) | null = null;
+  let resolveForwardedResponse: (() => void) | null = null;
+  const createdAgentSeen = new Promise<string>((resolve) => {
+    resolveCreatedAgent = resolve;
+  });
+  const delayedResponse = new Promise<void>((resolve) => {
+    resolveDelayedResponse = resolve;
+  });
+  const forwardedResponse = new Promise<void>((resolve) => {
+    resolveForwardedResponse = resolve;
+  });
+
+  await page.routeWebSocket(daemonWsRoutePattern(), (ws) => {
+    const server = ws.connectToServer();
+    const forwardToClient = (message: WebSocketMessage) => {
+      ws.send(message);
+      resolveForwardedResponse?.();
+    };
+
+    ws.onMessage((message) => {
+      server.send(message);
+    });
+
+    server.onMessage((message) => {
+      const sessionMessage = getSessionMessage(message);
+      const payload = sessionMessage ? getPayload(sessionMessage) : null;
+      if (sessionMessage?.type === "status" && payload?.status === "agent_created") {
+        const agentId = payload.agentId;
+        if (typeof agentId === "string") {
+          createdAgentId = agentId;
+          resolveCreatedAgent?.(agentId);
+        }
+      }
+
+      if (sessionMessage?.type === "fetch_agent_timeline_response") {
+        const agentId = payload?.agentId;
+        const direction = payload?.direction;
+        if (
+          !delayedResponseSeen &&
+          typeof agentId === "string" &&
+          agentId === createdAgentId &&
+          direction === "tail"
+        ) {
+          delayedResponseSeen = true;
+          resolveDelayedResponse?.();
+          if (releaseRequested) {
+            forwardToClient(message);
+            return;
+          }
+          delayedForwards.push(() => forwardToClient(message));
+          return;
+        }
+      }
+
+      ws.send(message);
+    });
+  });
+
+  return {
+    release() {
+      releaseRequested = true;
+      for (const forward of delayedForwards.splice(0)) {
+        forward();
+      }
+    },
+    waitForCreatedAgent: () => createdAgentSeen,
+    waitForDelayedResponse: () => delayedResponse,
+    waitForForwardedResponse: () => forwardedResponse,
+  };
+}