From a726bd73409352c3f522bcfbe6d37875e8d329d0 Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Thu, 16 Jul 2026 18:11:17 +0100
Subject: [PATCH] fix(qa): retry transient FTS settle races

---
 .../src/suite-runtime-agent-session.test.ts   | 49 +++++++++++++++++++
 .../qa-lab/src/suite-runtime-agent-session.ts | 43 +++++++++++++---
 2 files changed, 86 insertions(+), 6 deletions(-)

diff --git a/extensions/qa-lab/src/suite-runtime-agent-session.test.ts b/extensions/qa-lab/src/suite-runtime-agent-session.test.ts
index 82d4d30b8c04..187c015218ca 100644
--- a/extensions/qa-lab/src/suite-runtime-agent-session.test.ts
+++ b/extensions/qa-lab/src/suite-runtime-agent-session.test.ts
@@ -183,6 +183,55 @@ describe("qa suite runtime agent session helpers", () => {
     });
   });
 
+  it("retries transient FTS integrity mismatches while child transcripts settle", async () => {
+    const readEntries = vi
+      .fn()
+      .mockImplementationOnce(() => {
+        throw new Error(
+          'SQLite integrity_check failed for qa.sqlite: fts5: checksum mismatch for table "session_transcript_fts"',
+        );
+      })
+      .mockReturnValueOnce([
+        {
+          sessionKey: "session-1",
+          entry: { sessionId: "session-1", updatedAt: 10 },
+        },
+      ]);
+    vi.useFakeTimers();
+
+    const pending = readRawQaSessionStore(
+      { gateway: { tempRoot: "/tmp/qa-fts-settle" } } as never,
+      { readEntries, retryDelaysMs: [1] },
+    );
+    await vi.advanceTimersByTimeAsync(1);
+
+    await expect(pending).resolves.toEqual({
+      "session-1": { sessionId: "session-1", updatedAt: 10 },
+    });
+    expect(readEntries).toHaveBeenCalledTimes(2);
+  });
+
+  it("fails closed when an FTS integrity mismatch does not settle", async () => {
+    const mismatch = new Error(
+      'SQLite integrity_check failed for qa.sqlite: fts5: checksum mismatch for table "session_transcript_fts"',
+    );
+    const readEntries = vi.fn(() => {
+      throw mismatch;
+    });
+    vi.useFakeTimers();
+
+    const assertion = expect(
+      readRawQaSessionStore({ gateway: { tempRoot: "/tmp/qa-fts-persistent" } } as never, {
+        readEntries,
+        retryDelaysMs: [1],
+      }),
+    ).rejects.toThrow(mismatch.message);
+    await vi.runAllTimersAsync();
+
+    await assertion;
+    expect(readEntries).toHaveBeenCalledTimes(2);
+  });
+
   it("seeds QA session metadata and transcript messages in SQLite", async () => {
     const tempRoot = await makeTempDir("qa-session-seed-");
     const sessionId = "seeded-session";
diff --git a/extensions/qa-lab/src/suite-runtime-agent-session.ts b/extensions/qa-lab/src/suite-runtime-agent-session.ts
index 65796371f329..6545dbfaec74 100644
--- a/extensions/qa-lab/src/suite-runtime-agent-session.ts
+++ b/extensions/qa-lab/src/suite-runtime-agent-session.ts
@@ -43,6 +43,7 @@ type QaSessionTranscriptSeedParams = {
 };
 
 const SESSION_STORE_LOCK_RETRY_DELAYS_MS = [1_000, 3_000, 5_000] as const;
+const SESSION_STORE_FTS_SETTLE_RETRY_DELAYS_MS = [100, 250, 500, 1_000, 2_000] as const;
 
 type QaSessionTranscriptSummary = {
   assistantToolCallCounts: Record<string, number>;
@@ -67,6 +68,15 @@ function isSessionStoreLockTimeout(error: unknown) {
   );
 }
 
+function isSessionStoreFtsSettleRace(error: unknown) {
+  const text = formatErrorMessage(error);
+  return (
+    text.includes("SQLite integrity_check failed") &&
+    text.includes("fts5: checksum mismatch") &&
+    text.includes("session_transcript_fts")
+  );
+}
+
 function readSessionTranscriptEventMessage(event: unknown) {
   return isRecord(event) && isRecord(event.message) ? event.message : undefined;
 }
@@ -287,12 +297,33 @@ async function seedQaSessionTranscript(
   }
 }
 
-async function readRawQaSessionStore(env: Pick<QaSuiteRuntimeEnv, "gateway">) {
-  return Object.fromEntries(
-    listSessionEntries({ agentId: "qa", env: qaSessionRuntimeEnv(env.gateway.tempRoot) }).map(
-      ({ sessionKey, entry }) => [sessionKey, entry as QaRawSessionStoreEntry],
-    ),
-  );
+async function readRawQaSessionStore(
+  env: Pick<QaSuiteRuntimeEnv, "gateway">,
+  options: {
+    readEntries?: typeof listSessionEntries;
+    retryDelaysMs?: readonly number[];
+  } = {},
+) {
+  const runtimeEnv = qaSessionRuntimeEnv(env.gateway.tempRoot);
+  const readEntries = options.readEntries ?? listSessionEntries;
+  const retryDelaysMs = options.retryDelaysMs ?? SESSION_STORE_FTS_SETTLE_RETRY_DELAYS_MS;
+  for (let attempt = 0; attempt <= retryDelaysMs.length; attempt += 1) {
+    try {
+      return Object.fromEntries(
+        readEntries({ agentId: "qa", env: runtimeEnv }).map(({ sessionKey, entry }) => [
+          sessionKey,
+          entry as QaRawSessionStoreEntry,
+        ]),
+      );
+    } catch (error) {
+      if (!isSessionStoreFtsSettleRace(error) || attempt === retryDelaysMs.length) {
+        throw error;
+      }
+      // Child completion can publish before its transcript writer has settled the FTS state.
+      await sleep(retryDelaysMs[attempt]);
+    }
+  }
+  throw new Error("QA session store read failed after FTS settle retries");
 }
 
 async function readSessionTranscriptSummary(