OmniRoute/tests/unit/session-affinity-combo-timeout-eviction.test.ts

// #6219 follow-up — a COMBO per-model timeout must also evict the sticky session
// pin.
//
// Observed in production: combo "coding" [priority] pinned a session to one codex
// account. That account stalled past comboTargetTimeoutMs, the combo aborted the
// target and synthesized a 524, and — because a stall is not a quota/auth failure —
// nothing called markAccountUnavailable. The #6219 eviction only runs on that
// generic failover path, so the pin survived its full 30-minute TTL and every
// following request in the session was handed straight back to the stalled
// account: four consecutive requests, four 120s timeouts, "all targets exhausted"
// each time, while four sibling codex accounts sat healthy and unused.
//
// The fix classifies the abort reason (open-sse/services/combo/comboAbortReasons.ts)
// and evicts the connection-matched pin from the dispatch site in chat.ts.

import test from "node:test";
import assert from "node:assert/strict";
import fs from "node:fs";
import os from "node:os";
import path from "node:path";

const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-combo-timeout-affinity-"));
process.env.DATA_DIR = TEST_DATA_DIR;
process.env.API_KEY_SECRET = process.env.API_KEY_SECRET || "combo-timeout-affinity-test-secret";

const core = await import("../../src/lib/db/core.ts");
const affinityDb = await import("../../src/lib/db/sessionAccountAffinity.ts");
const pin = await import("../../src/sse/services/sessionAffinityPin.ts");
const abortReasons = await import("../../open-sse/services/combo/comboAbortReasons.ts");

const PROVIDER = "codex";
const SESSION = "session-combo-timeout";
const STALLED = "conn-stalled";
const HEALTHY = "conn-healthy";
const TTL = 30 * 60_000;

function abortedWith(reason: unknown): AbortSignal {
  const controller = new AbortController();
  controller.abort(reason);
  return controller.signal;
}

const timedOutSignal = () => abortedWith(new Error(abortReasons.COMBO_PER_MODEL_TIMEOUT_REASON));

test.beforeEach(() => {
  core.resetDbInstance();
  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
});

test.after(() => {
  core.resetDbInstance();
  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
});

test("evicts the pin when the combo per-model timeout abandons the pinned account", () => {
  affinityDb.upsertSessionAccountAffinity(SESSION, PROVIDER, STALLED, Date.now(), TTL);

  const evicted = pin.evictSessionAffinityOnComboTimeout({
    sessionKey: SESSION,
    provider: PROVIDER,
    connectionId: STALLED,
    modelAbortSignal: timedOutSignal(),
  });

  assert.equal(evicted, true, "a timed-out pinned account must lose its pin");
  assert.equal(
    affinityDb.getSessionAccountAffinity(SESSION, PROVIDER, TTL),
    null,
    "the next request must be free to pick another account"
  );
});

test("leaves the pin intact on a client disconnect", () => {
  affinityDb.upsertSessionAccountAffinity(SESSION, PROVIDER, STALLED, Date.now(), TTL);

  const evicted = pin.evictSessionAffinityOnComboTimeout({
    sessionKey: SESSION,
    provider: PROVIDER,
    connectionId: STALLED,
    modelAbortSignal: abortedWith(new Error("request_signal_aborted")),
  });

  assert.equal(evicted, false, "a client hanging up says nothing about account health");
  assert.equal(
    affinityDb.getSessionAccountAffinity(SESSION, PROVIDER, TTL)?.connectionId,
    STALLED,
    "pin must survive so the session keeps its prompt-cache locality"
  );
});

test("leaves the pin intact when a hedged sibling cancelled this target", () => {
  affinityDb.upsertSessionAccountAffinity(SESSION, PROVIDER, STALLED, Date.now(), TTL);

  const evicted = pin.evictSessionAffinityOnComboTimeout({
    sessionKey: SESSION,
    provider: PROVIDER,
    connectionId: STALLED,
    modelAbortSignal: abortedWith(new Error(abortReasons.COMBO_HEDGE_CANCELLED_REASON)),
  });

  assert.equal(evicted, false, "losing a hedge race is not an account failure");
  assert.equal(affinityDb.getSessionAccountAffinity(SESSION, PROVIDER, TTL)?.connectionId, STALLED);
});

test("leaves the pin intact when the dispatch was never aborted", () => {
  affinityDb.upsertSessionAccountAffinity(SESSION, PROVIDER, STALLED, Date.now(), TTL);

  const evicted = pin.evictSessionAffinityOnComboTimeout({
    sessionKey: SESSION,
    provider: PROVIDER,
    connectionId: STALLED,
    modelAbortSignal: new AbortController().signal,
  });

  assert.equal(evicted, false);
  assert.equal(affinityDb.getSessionAccountAffinity(SESSION, PROVIDER, TTL)?.connectionId, STALLED);
});

test("never evicts a pin that points at a different (healthy) account", () => {
  affinityDb.upsertSessionAccountAffinity(SESSION, PROVIDER, HEALTHY, Date.now(), TTL);

  const evicted = pin.evictSessionAffinityOnComboTimeout({
    sessionKey: SESSION,
    provider: PROVIDER,
    connectionId: STALLED,
    modelAbortSignal: timedOutSignal(),
  });

  assert.equal(evicted, false, "connection-matched guard must hold");
  assert.equal(affinityDb.getSessionAccountAffinity(SESSION, PROVIDER, TTL)?.connectionId, HEALTHY);
});

test("no-ops without a session key or connection id", () => {
  const signal = timedOutSignal();
  assert.equal(
    pin.evictSessionAffinityOnComboTimeout({
      sessionKey: null,
      provider: PROVIDER,
      connectionId: STALLED,
      modelAbortSignal: signal,
    }),
    false
  );
  assert.equal(
    pin.evictSessionAffinityOnComboTimeout({
      sessionKey: SESSION,
      provider: PROVIDER,
      connectionId: null,
      modelAbortSignal: signal,
    }),
    false
  );
});

test("isComboPerModelTimeoutAbort accepts a bare string abort reason", () => {
  assert.equal(
    abortReasons.isComboPerModelTimeoutAbort(
      abortedWith(abortReasons.COMBO_PER_MODEL_TIMEOUT_REASON)
    ),
    true
  );
  assert.equal(abortReasons.isComboPerModelTimeoutAbort(null), false);
});

test("the combo timeout runner aborts with the shared reason constant", () => {
  const src = fs.readFileSync(
    new URL("../../open-sse/services/combo/targetTimeoutRunner.ts", import.meta.url),
    "utf8"
  );
  assert.match(
    src,
    /const abortErr = new Error\(COMBO_PER_MODEL_TIMEOUT_REASON\)/,
    "the runner must construct the shared timeout reason"
  );
  assert.match(
    src,
    /timeoutController\.abort\(abortErr\)/,
    "the runner must abort with that Error so the eviction predicate matches"
  );
});

test("chat.ts routes its upstream dispatch through the eviction-aware seam", () => {
  const src = fs.readFileSync(new URL("../../src/sse/handlers/chat.ts", import.meta.url), "utf8");
  assert.match(
    src,
    /dispatchChatWithAffinityEviction\(/,
    "chat.ts must dispatch through the seam that owns the eviction"
  );
  assert.doesNotMatch(
    src,
    /await executeChatWithBreaker\(/,
    "chat.ts must not bypass the seam by calling executeChatWithBreaker directly"
  );
});

test("the dispatch seam evicts when a dispatch is abandoned", () => {
  const src = fs.readFileSync(
    new URL("../../src/sse/handlers/chatDispatch.ts", import.meta.url),
    "utf8"
  );
  assert.match(
    src,
    /evictSessionAffinityOnComboTimeout\(/,
    "chatDispatch.ts must call the eviction"
  );
});