Using Default Values for Schema Instances in Unit Tests

class Foo extends Schema.Class<Foo>("Foo")({
    a: Schema.String,
    b: Schema.Boolean,
    c: Schema.Number,
    d: Schema.Number
}){}

const dosomething = (f: Foo) => {
    return f.c + 42
}

const res = dosomething(Foo.make({c: 5})) // Foo.make needs a, b and d obviously
assert(res === 47)

class Rule extends Schema.Class<Rule>("Rule")({
// all my fields
}) {
        private static DEFAULTS = {} // define some default values for my fields
    static createWithDefaults(props: Partial<Rule>) {
        return new Rule({
            ...Rule.DEFAULTS,
            ...props,
        })
    }

        static createPromotion(rebate: number) {return this.crateWithDefaults({rebate, type: 'promotion'}}
}
// finally in my tests I can create a Rule intance with the fields I want `Rule.createWithDefaults({refund: true})`