Sync configuration being undefined or missing entirely should produce the same behaviour

[kraenhansen]

How frequently does the bug occur?

All the time

Description

When opening a Realm and passing in undefined as the sync property on the config the library should behave the same as if the key is missing entirely. This is currently not the case.

If the property is present but the value is undefined, opening the Realm will throw:

TypeError: Cannot read property 'newRealmFileBehavior' of undefined

The offending line is this: https://github.com/realm/realm-js/blob/master/lib/extensions.js#L167

It would be great to support opening the Realm as a local Realm if config.sync === true as well.

Stacktrace & log output

No response

Can you reproduce the bug?

Yes, always

Reproduction Steps

No response

Version

10.8.0

What SDK flavour are you using?

Local Database only

Are you using encryption?

No, not using encryption

Platform OS and version(s)

N/A

Build environment

No response