Unable to deploy functions with Typescript

Version info

firebase-functions: 2.1.0

firebase-tools: 6.1.2

firebase-admin: 6.4.0

Test case

When using Typescript together with firebase functions I’m unable to deploy any code because of the following error:

Error: mod.hasOwnProperty is not a function

Typescript version: 3.2.2

Steps to reproduce

functions/index.ts

import * as functions from 'firebase-functions'
import * as admin from 'firebase-admin';

admin.initializeApp(functions.config().firebase);
admin.firestore().settings({ timestampsInSnapshots: true });
const env = functions.config();
...

Run $ firebase deploy --only functions

Result

✔  functions: Finished running predeploy script.
i  functions: ensuring necessary APIs are enabled...
✔  functions: all necessary APIs are enabled
i  functions: preparing functions directory for uploading...

Error: mod.hasOwnProperty is not a function

Were you able to successfully deploy your functions?

No. I got the following error message - Error: mod.hasOwnProperty is not a function

Expected behavior

Functions should get deployed.

Actual behavior

Error: mod.hasOwnProperty is not a function

[joehan]

@mlejva I took a look at the error message that you are getting, and I believe it is coming from extractTriggers.js (https://github.com/firebase/firebase-tools/blob/master/src/extractTriggers.js) in firebase-tools. This code is run when you ‘firebase deploy’ in order to find the names of your functions from what you export in index.ts. firebase deploy expects that src/index.ts is only exporting functions created via firebase-functions (or custom functions written to the same spec). You shouldn’t export other things in your index.ts file. Hopefully this helps! I’m going to close this since its not an issue with our codebase, but I’m happy to clarify any other questions you may have.

[matheo]

I just found that some bundlers/optimizers can remove the __proto__ functions of the Object and that will break firebase-tools logic. See firebase/firebase-tools#1687