getter/setter per attribute

[soletan]

As a developer
I would like to declare getter/setter
to control direct read/write access on attributes of a model.

Proposal:

exports.myAttribute = {
    type: "string",
    getter( raw ) {
        return someProcessing( raw );
    },
    setter( newValue, oldValue ) { 
        if ( !newValue ) {
            throw new TypeError( "missing actual value" );
        }

        return computedNewValue( newValue ); 
    },
};

• Getters and setters are provided as declaration properties of an attribute.

• They are supported without regards to the actual type of attribute.

• Declaring either getter or setter should result in actual value accessible via getter/setter, only.

• Declaring only getter or only setter should throw exception in case of using the lacking one by default.

• Getters are invoked without any particular context (so it's ok to use arrow functions rather than requiring access to some particular context via this to work).

• Getters are invoked with the attribute's current value as stored in backend.

• Getters are designed to return the value as desired or throw exception in case of getting value is prohibited.

• Setters are invoked without any particular context (so it's ok to use arrow functions rather than requiring access to some particular context via this to work).

• Setters are invoked with attribute's new value to be and its current value to be replaced.

• Setters are expected to return the eventually new value of attribute or throw exception in case of setting value is prohibited.