mobx/src/types/overrideannotation.ts

Simple, scalable state management.

import { die, Annotation, hasProp, ObservableObjectAdministration, MakeResult } from "../internal"

const OVERRIDE = "override"

export const override: Annotation = {
    annotationType_: OVERRIDE,
    make_,
    extend_
}

export function isOverride(annotation: Annotation): boolean {
    return annotation.annotationType_ === OVERRIDE
}

function make_(this: Annotation, adm: ObservableObjectAdministration, key): MakeResult {
    // Must not be plain object
    if (__DEV__ && adm.isPlainObject_) {
        die(
            `Cannot apply '${this.annotationType_}' to '${adm.name_}.${key.toString()}':` +
                `\n'${this.annotationType_}' cannot be used on plain objects.`
        )
    }
    // Must override something
    if (__DEV__ && !hasProp(adm.appliedAnnotations_!, key)) {
        die(
            `'${adm.name_}.${key.toString()}' is annotated with '${this.annotationType_}', ` +
                `but no such annotated member was found on prototype.`
        )
    }
    return MakeResult.Cancel
}

function extend_(this: Annotation, adm, key, descriptor, proxyTrap): boolean {
    die(44, this.annotationType_)
}