Accessing the model in default parameter callback

[rafsawicki]

In version 1.x, a default field callback was called with the current model being passed as a parameter, so the following pattern was possible for setting range keys and index fields:

const schema = new Schema({
  id: String,
  rangeKey: {
    type: String,
    rangeKey: true,
    default: (model) => `${model.foo}_${model.bar}`,
    forceDefault: true,
  },
  foo: String,
  bar: String,
});

Based on my search, the parameter was added in 0.8.0, but it seems to have been removed at some point in time. We use this feature quite extensively in our codebase and are looking into upgrading from 1.x. Is there any other way to access the model in a default callback or setting default fields based on other model values?