Meta getProperty mutates underlying storage

[danielgtaylor]

This leads to non-obvious behavior which I think we need to properly define or change. Here is the implementation as it stands:

pimitives.es6#34-40

class Meta {
  getProperty(name, value) {
    if (!this.meta[name]) {
      this.meta[name] = registry.toType(value);
    }

    return this.meta[name];
  }
}

Here is the surprising part:

const element = new ElementType();

console.log(element.toCompactRefract());
// => ['element', {}, {}, null]

// Access the non-existing name property
element.name;

// What? Now there is a meta name for some reason!?
console.log(element.toCompactRefract());
// => ['element', {name: ''}, {}, null]

// Try to get something from meta with a default if not found
element.getProperty('foo', 'bar');

// What? Now my default value is getting serialized!
console.log(element.toCompactRefract());
// => ['element', {name: '', foo: 'bar'}, {}, null]

I'm sorry I glossed over this in the initial review! I believe the code is written this way to cache the conversion to refract element classes for the default value, but I think we need to either do that conversion each time or keep a separate cache that doesn't mutate the original meta values..

Thoughts @smizell?

[smizell]

@danielgtaylor Great find here. I think you're right. I'll be thinking on this as I do not think what I currently wrote is helpful to the user. I also think I should have made getProperty a private method.

I'll be thinking on this. I'm working on a proposal for Minim that I'll be running by you soon.