test for await db.set in createAuthor

src/tests/backend/specs/regression-db.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const AuthorManager = require('../../../node/db/AuthorManager');
+const assert = require('assert').strict;
+const common = require('../common');
+const db = require('../../../node/db/DB');
+
+describe(__filename, function () {
+  let setBackup;
+
+  before(async function () {
+    await common.init();
+    setBackup = db.set;
+
+    db.set = async (...args) => {
+      // delay db.set
+      await new Promise((resolve) => { setTimeout(() => resolve(), 500); });
+      return await setBackup.call(db, ...args);
+    };
+  });
+
+  after(async function () {
+    db.set = setBackup;
+  });
+
+  it('regression test for missing await in createAuthor (#5000)', async function () {
+    this.timeout(700);
+    const {authorID} = await AuthorManager.createAuthor(); // Should block until db.set() finishes.
+    assert(await AuthorManager.doesAuthorExist(authorID));
+  });
+});