Setting a type `ctor` fails if called before the type is registered into the namespace

[ericmorand]

protobuf.js version: 7.4.0

Setting a type ctor fails if called before the type is registered into the namespace.

Let's consider the following code:

import {Field, Message, Root, Type} from "protobufjs";

export const namespace = new Root();

const anyType = new Type('Any')
    .add(new Field('y', 1, 'string'));

const fooType = new Type('Foo')
    .add(new Field('x', 1, 'Any'));

fooType.ctor = class extends Message {

};

namespace
    .add(anyType)
    .add(fooType);

fooType.create({
    x: true
});

This code fails with a Error: no such Type or Enum 'Any' in Type Foo error.

Now, let's try registering the ctor of fooType after the type was registered into the namespace.

import {Field, Message, Root, Type} from "protobufjs";

export const namespace = new Root();

const anyType = new Type('Any')
    .add(new Field('y', 1, 'string'));

const fooType = new Type('Foo')
    .add(new Field('x', 1, 'Any'));

namespace
    .add(anyType)
    .add(fooType);

fooType.ctor = class extends Message {

};

fooType.create({
    x: true
});

This time, the code succeeds.

Except if I missed something, this requirement to have the ctor property set after a type is registered into the namespace is not documented.

Ot maybe it is a bug. I understand that the type Foo depends on the type Bar, but it seems very unexpected that the ctor setter actually checks the existence of the other types before proceeding. I assumed it would be deffered until execution (i.e. calls to create or toObject).

If it is a design decision, I'd be curious to understand its rational. Regardless, I think it needs to be documented. I spent a lot of time trying to figure out the issue and I assume I've not been the only one and won't be the last.