Partial update array - create / initialize a null array

[alexjamesbrown]

Is it possible to add an item to an array using partial update - for an array that doesn't yet exist in the document?
Now that I've typed that out, it does sound like a silly question, but to illustrate the point, I've extended the CosmosGettingStarted project slightly, and added a property to the Family object:

public class Family
{
// omitted for brevity
public Address Address { get; set; }

    public IEnumerable<Address> AddressList { get; set; }
    
    public override string ToString()
    {
        return JsonConvert.SerializeObject(this);
    }
}

Notice I've added `AddressList

What I want to do, is a partial update, something like this:

        var patchResponse = await this.container.PatchItemAsync<Family>("Wakefield.7", new PartitionKey("Wakefield"),  new[]
        {
            PatchOperation.Add("/AddressList/0", new Address { State = "State 0", County = "County 0", City = "City 0" })
        });

This fails - because AddressList doesn't exist:

The segment (AddressList) has to be an array or an object to operate upon.

If I init the AddressList in the ctor of family, this works as expected.