Required Fields and Struct Disjunctions

[brandoshmando]

I'm playing around with required fields to get a feel for how they operate and I'm running into a case where I'd expect one concrete output but I'm getting another non-concrete output.

Given the following:

_test: (close({
    method: "GET"
    resource: "policies"
    name!: string
    out: "list"
}) | {
    method: "GET"
    resource: "policies"
    name!: string
    id!: string
    
    out: "detail"
})

out: _test & { name:"books" }

I'd expect the following concrete output:

out: {
    method: "GET"
    resource: "policies"
    name: "books"
    out: "list"
}

Because this represents the "most concrete" possible value.

Instead I'm getting an incomplete value:

out: {
	method:   "GET"
	resource: "policies"
	name:     "books"
	out:      "list"
} | {
	method:   "GET"
	resource: "policies"
	name:     "books"
	id!:      string //<- here
	out:      "detail"
}

I'd expect cue to recognize the most concrete path and output that value.

Am I misinterpreting how required fields should be working in this case? It seems that the most concrete path isn't being output. Tip Playground link -> https://tip.cuelang.org/play/?id=3PZ4BLMJxHQ#cue@export@cue

[brandoshmando]

FWIW, when providing the ID, it does output the correct struct.
Tip Playground link -> https://tip.cuelang.org/play/?id=F4-ZcNRNs1l#cue@export@cue