bug(reducers): updates to arrays inside documents don't work as expected

Do you want to request a feature or report a bug?
bug

What is the current behavior? If you store an array inside a firestore document (e.g. { content: ['an', 'array'] }) and update that document such that the array is shorter ({ content: ['single'] }), the update action that fires merges the arrays and doesn’t delete the extra elements ({ content: ['single', 'array'] }).

Note that { content: ['single'] } is what is in the firestore database at this stage.

What is the expected behavior? For the array to be pruned

Which versions of dependencies, and which browser are affected by this issue? Did this work in previous versions or setups? Definitely exists in 0.5.8, unclear if it worked previously

Steps to reproduce and if possible a minimal demo of the problem via codesandbox or similar. See pull request and the test attached.

[GuillemotF]

I have a similar behaviour with objects in a document (instead of an array) when removing a property.

Example :

const documentUpdate = {};
documentUpdate['someObject.someProperty'] =  firestore.FieldValue.delete();
firestore.update(
      {
        collection: 'test',
        doc: 'someId',
      },
      documentUpdate,
);

Will correctly update data state in redux but not the ordered one.

Edit : Your PR also fixes this issue

[YuvalKlein]

Yeesss!! working! thank you!