Improve speed of getUnreadByConversationAndMarkRead query

ts/test-node/sql/migration_1540_test.node.ts

@@ -0,0 +1,94 @@
+// Copyright 2025 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+import { assert } from 'chai';
+
+import { type WritableDB } from '../../sql/Interface.std.js';
+import { sql, sqlFragment } from '../../sql/util.std.js';
+import { createDB, explain, updateToVersion } from './helpers.node.js';
+
+describe('SQL/updateToSchemaVersion1540', () => {
+  let db: WritableDB;
+
+  beforeEach(() => {
+    db = createDB();
+    updateToVersion(db, 1540);
+  });
+  afterEach(() => {
+    db.close();
+  });
+
+  const CORE_UPDATE_QUERY = sqlFragment`
+    UPDATE messages
+    INDEXED BY messages_conversationId_expirationStartTimestamp
+    SET
+        expirationStartTimestamp = 342342
+    WHERE
+        conversationId = 'conversationId' AND
+        type IN ('incoming', 'poll-terminate') AND
+        hasExpireTimer IS 1 AND
+        received_at < 1304923
+    `;
+
+  const UPDATE_WHEN_NULL_START_QUERY = sqlFragment`
+        ${CORE_UPDATE_QUERY} AND
+        expirationStartTimestamp IS NULL
+    `;
+  const UPDATE_WHEN_LATE_START_QUERY = sqlFragment`
+        ${CORE_UPDATE_QUERY} AND
+        expirationStartTimestamp > 342342
+    `;
+
+  it('uses index efficiently with null start + storyId condition', () => {
+    const detail = explain(
+      db,
+      sql`
+        ${UPDATE_WHEN_NULL_START_QUERY} AND
+          storyId is NULL
+        `
+    );
+
+    assert.strictEqual(
+      detail,
+      'SEARCH messages USING INDEX messages_conversationId_expirationStartTimestamp' +
+        ' (conversationId=? AND expirationStartTimestamp=?)'
+    );
+  });
+  it('uses index efficiently with null start + no storyId condition', () => {
+    const detail = explain(
+      db,
+      sql`
+        ${UPDATE_WHEN_NULL_START_QUERY}
+        `
+    );
+
+    assert.strictEqual(
+      detail,
+      'SEARCH messages USING INDEX messages_conversationId_expirationStartTimestamp' +
+        ' (conversationId=? AND expirationStartTimestamp=?)'
+    );
+  });
+
+  it('uses index efficiently with lateStart query and no storyId condition', () => {
+    const detail = explain(db, sql`${UPDATE_WHEN_LATE_START_QUERY}`);
+
+    assert.strictEqual(
+      detail,
+      'SEARCH messages USING INDEX messages_conversationId_expirationStartTimestamp' +
+        ' (conversationId=? AND expirationStartTimestamp>?)'
+    );
+  });
+
+  it('uses index efficiently with lateStart query and storyId condition', () => {
+    const detail = explain(
+      db,
+      sql`${UPDATE_WHEN_LATE_START_QUERY} AND
+          storyId is NULL`
+    );
+
+    assert.strictEqual(
+      detail,
+      'SEARCH messages USING INDEX messages_conversationId_expirationStartTimestamp' +
+        ' (conversationId=? AND expirationStartTimestamp>?)'
+    );
+  });
+});