static-deep-properties.md

Static deep properties

The static deep properties are properties attached to stamp itself. But unlike regular (shallow) static properties these are deeply merged together by stamp deep merging algorithm.

const SchemaTypes = stampit.deepStatics({
  Types: {
    String,
    Number,
    Array
  }
})

const ObjectIdSchemaType = stampit.deepStatics({
  Types: {
    ID: String,
    ObjectId: require('./object-id')
  }
})

const Schema = stampit(SchemaTypes, ObjectIdSchemaType, { // stamp deep merging kicks in this line
  init(data, { stamp }) {
    // stamp.Types.String, stamp.Types.ID, ...
  }
})

// Schema.Types.String
// Schema.Types.Number
// Schema.Types.Array
// as well as
// Schema.Types.ID
// Schema.Types.ObjectId

Descriptor merging algorithm

The staticDeepProperties are deeply merged using stamp deep merging algorithm. See below - the Types value is always a new object.

SchemaTypes.Types !== Schema.Types // NEVER EQUAL! NO MATTER WHAT!

Sometimes a regular (shallow) static property has the same name as a deep static property. The shallow static property always wins.

const NullTypes = stampit.statics({
  Types: null
})

const NoTypesSchema = Schema.compose(NullTypes)

NoTypesSchema.Types === null // the regular property overwrites deep property

Other ways to add static deep properties

Exactly the same stamp can be created in few ways. Here they all are.

const myTypes = { String, ID: String, Number, Array }

const AuthServiceToken = stampit({
  deepStatics: {
    Types: myTypes
  }
})

const HasLog = stampit({
  staticDeepProperties: {
    Types: myTypes
  }
})

const HasLog = stampit.deepStatics({
  Types: myTypes
})

const HasLog = stampit.staticDeepProperties({
  Types: myTypes
})

const HasLog = stampit().deepStatics({
  Types: myTypes
})

const HasLog = stampit().staticDeepProperties({
  Types: myTypes
})