When trying to update an array in Cloud Firestore you might run into this error: FieldValue.arrayUnion() called with invalid data. Nested arrays are not supported.
However, that error might be a bit misleading. The following code will crash:
firebase.firestore.FieldValue.arrayUnion(['javascript', 'typescript']);
You don't have a nested array per se but your code will fail because Firestore requires you to pass those items individually. All you have to do is using the spread operator instead:
firebase.firestore.FieldValue.arrayUnion(...['javascript', 'typescript']);
Discussion (2)
Really helpful post....was searching for "Adding an array into a Firebase Array Field.", with no luck. Finally, found a proper verified no for direct use of arrayUnion. Thanks a lot man.
You saved my day! Thank you!