How to get an error if a getter or field is missing?

Help Requests
1

Here is a simple Aurelia class :

export class MyClass {

    @bindable public someValue: number;

    constructor( ) {   }

    @computedFrom("someValue")
    get isPositive() {
        return someValue > 0;
    }

And the view :

<template>
            <div if.bind="isPositive"></div>
</template>

How to make Aurelia report an error if “isPositive” does not exist?
At the moment, it will be confusingly and silently be turned into “false”. I will never know that something’s not working as it should just because I forgot the getter.

2

Maybe I can try to work with coercion settings, as seen below this anchor : Bindable properties | The Aurelia 2 Docs

At least I will get undefined instead of 0.