V3 InMemoryCache: Object Fieldname Characters too Restrictive

I have a nested object that uses Guids as the fieldname:

var user = {
  id: '1',
  nestedObject: {
     'd7eb901a-cc21-4f8f-93f4-0408406e6a00': 'some value'
  }
}

I use cache.writeData to update the nestedObject:

cache.writeData({
  id: defaultDataIdFromObject(user)
  data: { 
    nestedObject: {
      'd7eb901a-cc21-4f8f-93f4-0408406e6a00': 'a different value'
    }
 },
});

Intended outcome: I am expecting the imMemoryCache to update the User to the following value:

{
  id: '1',
  nestedObject: {
     'd7eb901a-cc21-4f8f-93f4-0408406e6a00': 'a different value'
  }
}

Actual outcome: In actuality, the keys for the nested object get messed up (seem to get doubled):

{
  id: '1',
  nestedObject: {
     'd7eb901a-cc21-4f8f-93f4-0408406e6a00-d7eb901a-cc21-4f8f-93f4-0408406e6a00': 'a different value'
  }
}

How to reproduce the issue: Follow steps above to reproduce

Notes

• This is possible due to the limited characters in the FieldNamePattern variable in cache/inMemory/helpers.ts
• There are a lot more valid JSON key characters that are missing. However, the hyphen was the only one I was running into in this example
• Feature Request Sidenote: The ability to pass in a custom merge algorithm could be useful
• Possible Bug sidenote: Due to the merge algorithm, it seems like it is not possible to reset a field back to undefined. Is this correct, or intended behaviour? And, if intended, is there a way to set a field back to undefined in cache?

Versions System: OS: macOS 10.15.2 Binaries: Node: 12.12.0 - /usr/local/bin/node Yarn: 1.19.1 - /usr/local/bin/yarn npm: 6.9.0 - /usr/local/bin/npm Browsers: Chrome: 79.0.3945.88 Safari: 13.0.4 npmPackages: @apollo/client: ^3.0.0-beta.10 => 3.0.0-beta.16 @apollo/react-hooks: ^3.2.0-beta.0 => 3.2.0-beta.0 apollo-link-debounce: ^2.1.0 => 2.1.0

[jamshally]

@hwillson - yes, thanks, these are all resolved for me now as of v3.0.0-beta.24

[benjamn]

@ahrnee I think all of these problems can be solved by making the evict method more powerful: https://github.com/apollographql/apollo-client/pull/5773