Cannot compose sealed ObjectModels

[dogrover]

I'm trying to define a nested object model, where one of the child objects is sealed. For example, this works fine (using v3.0.1):

const Dependency = ObjectModel({
  name: String,
});

const Package = ObjectModel({
  name: String,
  data: {
    description: String,
    hard_dependencies: {
      one: Dependency,
      two: Dependency,
    }
  }
});

const test_item = new Package({
  name: "Test item",
  data: {
    description: "A test item",
    hard_dependencies: {
        one: {
        name: "module 1",
        bad_attr: false,
      },
      two: {
        name: "module 2",
      }
    }
  }
});

But I get an error when I change the Dependency definition to this:

const Dependency = ObjectModel({
  name: String,
}).sealed=true;

The error is:

Uncaught TypeError: expecting data.hard_dependencies.one to be true, got Object { name: "module 1", nope: false } expecting data.hard_dependencies.two to be true, got Object { name: "module 2" } at window.onload (VM180:72)

This seems to be happening because Dependency now gets the value of the assignment from sealed=true, rather than the function that it should be.

I've tried:

var Dependency = ObjectModel({
  name: String,
});
Dependency.sealed=true;

but it has no effect.

Could you provide an example on how to use the sealed property?

[sylvainpolletvillard]

Hello,

In your first example, you are assigning Dependency to true (Dependency = model.sealed = true) The second code is the correct one.

However, currently, the sealed property prevent extensions on future mutations, and not initial assignment. Basically it "seals" the instance after it has been instanciated with initial values. If you try test_item.data.hard_dependencies.one.bad_attr = true afterwards, you will get the intended error message.

I agree this is not intuitive, and I plan to change this and throw errors when undeclared props are passed to sealed model constructors.

[sylvainpolletvillard]

Note that if you want all your models to be sealed, you can set ObjectModel.prototype.sealed = true However, this is not something I would recommend since it prevents model extensions.

[dogrover]

Thanks for the update. And thanks for the module; exactly what I needed! I'll see if I can modify the target code to deal with checking for extra attributes after initial assignment.

[sylvainpolletvillard]

Currently working on it. Stay tuned

[sylvainpolletvillard]

Here we go, v3.1.0 released:

• sealed models now prevent all undeclared properties at initial or future assignments, on direct and nested properties
• add a params option to object models constructor if you want to do it one-line: Model(def, { sealed: true })
• add a dedicated section in the docs for sealed models: http://objectmodel.js.org/#doc-sealed