Using tasks that perform on property update

computed-task.js

// Mixin
import { task } from 'ember-concurrency';
import Mixin from '@ember/object/mixin';

export default Mixin.create({

	computedTask(keyToWatch, genFunc) {
		// Maybe check if this wasn't previously set up
		
		// Ready the task
		Ember.defineProperty(this, 'taskToRun', task(genFunc).restartable());

		// Add the observer that performs the task on value update
		this.addObserver(keyToWatch, () => {
			this.taskToRun.perform();
		});

		// Run the first time
		this.taskToRun.perform();
	}

});

usage.js

import ComputedTask from 'computed-tasks/mixins/my-comp-task';
import { timeout } from 'ember-concurrency';
import { later } from '@ember/runloop';
import Component from '@ember/component';

export default Component.extend(ComputedTask, {

	mSetupComputedTaskExample() {
		
		this.computedTask('foo', function * () {
			
			yield timeout(1000);
			let randomVal = Math.random();
			let fooVal = this.get('foo');
			
			this.set('newFoo', `fooVal = ${fooVal}, randomVal =  ${randomVal}`);
		});

	},

	didInsertElement() {
		// Initial value
		this.set('foo', 'Physics');

		this.mSetupComputedTaskExample();

		// To see it in action
		later(this, function(){
			this.set('foo', 'Biology');
		}, 2000);
	}

});