Please run down the following list and make sure you've tried the usual "quick fixes":

• Search the issues already opened: https://github.com/googleapis/nodejs-firestore/issues
• Search the issues on our "catch-all" repository: https://github.com/googleapis/google-cloud-node
• Search StackOverflow: http://stackoverflow.com/questions/tagged/google-cloud-platform+node.js

If you are still having issues, please be sure to include as much information as possible:

Environment details

• OS:
• Node.js version: 10.15.1
• npm version:
• @google-cloud/firestore version: 1.0.2

Steps to reproduce

1. Call firestore.runTransaction with an async function
2. You will get the error Error: Argument "updateFunction" is not a valid function.
3. The issue is that isFunction checks for [object Function] when an async function produces [object AsyncFunction]

Making sure to follow these steps will guarantee the quickest resolution possible.

Thanks!