pikasTech-HWLAB/internal/cloud/workbench-kafka-rail-stream.test.ts

import { expect, test } from "bun:test";

import { createWorkbenchKafkaRailProjectionStream } from "./workbench-kafka-rail-stream.ts";

test("rail stream emits scoped snapshots and only semantic live deltas", async () => {
  const summaries = new Map([
    ["ses_rail_a", railSummary("ses_rail_a", "1", "running")],
    ["ses_rail_b", railSummary("ses_rail_b", "2", "completed")]
  ]);
  const subscribers = new Set<(envelope: unknown) => void>();
  const delivered: any[] = [];
  const bridge = {
    async waitWorkbenchSessionRailReady() { return { ready: true }; },
    workbenchSessionSummaries({ sessionIds = [] } = {}) {
      return { ok: true, sessions: sessionIds.map((sessionId: string) => summaries.get(sessionId)) };
    },
    subscribeLiveHwlabEvents(listener: (envelope: unknown) => void) {
      subscribers.add(listener);
      return () => subscribers.delete(listener);
    }
  };
  const stream = createWorkbenchKafkaRailProjectionStream({
    bridge,
    sessionIds: ["ses_rail_b", "ses_rail_a"],
    deliver(payload: unknown) { delivered.push(payload); return true; }
  });

  await stream.start();
  expect(delivered.map((item) => [item.phase, item.sessionId, item.session.status])).toEqual([
    ["snapshot", "ses_rail_a", "running"],
    ["snapshot", "ses_rail_b", "completed"]
  ]);

  for (const listener of subscribers) listener({ schema: "hwlab.event.v1", sessionId: "ses_rail_a", event: { type: "assistant" } });
  await Promise.resolve();
  expect(delivered).toHaveLength(2);

  summaries.set("ses_rail_a", railSummary("ses_rail_a", "4", "completed"));
  for (const listener of subscribers) listener({ schema: "hwlab.event.v1", sessionId: "ses_rail_a", event: { type: "result", terminal: true } });
  await Promise.resolve();
  await Promise.resolve();
  expect(delivered.map((item) => [item.phase, item.sessionId, item.session.status])).toEqual([
    ["snapshot", "ses_rail_a", "running"],
    ["snapshot", "ses_rail_b", "completed"],
    ["live", "ses_rail_a", "completed"]
  ]);
  expect(stream.status()).toMatchObject({ live: true, snapshotCount: 2, liveCount: 1 });
  stream.stop();
  expect(subscribers.size).toBe(0);
});

test("rail stream waits for the first user-derived summary without failing the active session", async () => {
  const sessionId = "ses_new_without_user";
  const summaries = new Map<string, ReturnType<typeof railSummary>>();
  const subscribers = new Set<(envelope: unknown) => void>();
  const delivered: any[] = [];
  const failures: unknown[] = [];
  const bridge = {
    async waitWorkbenchSessionRailReady() { return { ready: true }; },
    workbenchSessionSummaries({ sessionIds = [] } = {}) {
      return { ok: true, sessions: sessionIds.map((id: string) => summaries.get(id)).filter(Boolean) };
    },
    subscribeLiveHwlabEvents(listener: (envelope: unknown) => void) {
      subscribers.add(listener);
      return () => subscribers.delete(listener);
    }
  };
  const stream = createWorkbenchKafkaRailProjectionStream({
    bridge,
    sessionIds: [sessionId],
    deliver(payload: unknown) { delivered.push(payload); return true; },
    onFailure(error: unknown) { failures.push(error); }
  });

  await stream.start();
  expect(delivered).toEqual([]);
  expect(failures).toEqual([]);

  summaries.set(sessionId, railSummary(sessionId, "7", "running"));
  for (const listener of subscribers) listener({ schema: "hwlab.event.v1", sessionId, event: { type: "user" } });
  await Promise.resolve();
  await Promise.resolve();

  expect(delivered).toHaveLength(1);
  expect(delivered[0]).toMatchObject({ phase: "live", sessionId, session: { firstUserMessagePreview: `title ${sessionId}` } });
  expect(failures).toEqual([]);
  stream.stop();
});

function railSummary(sessionId: string, offset: string, status: string) {
  return {
    sessionId,
    firstUserMessagePreview: `title ${sessionId}`,
    lastUserMessageAt: "2026-07-22T08:00:00.000Z",
    lastTraceId: `trc_${sessionId}`,
    status,
    revision: { topic: "hwlab.event.v1", partition: 0, offset, valuesRedacted: true },
    valuesRedacted: true
  };
}