Here is the source code for the test case. We have a few tests coded that provide enough to get us started.

A few key touch points are highlighted. We just insert the name "Counter" into those slots, and then we're ready to add the "//Tests".

/*
	File: model-test-case.js
	Class: CounterTestCase
	
	//framework
	1) Code tagged with the tag //framework requires
	a minor edit or no edit (comment by tag will inform)
	2) The expression "extends superClass" below is also
	part of the framework support (no edit required)
*/

//framework -- test case name
addTestCase("CounterTestCase");

class CounterTestCase extends TestCase {
	//ivars: unit
	
	//-----------------
	//Unit Test Support
	
	getUnitName() {
		//framework -- model type (class)
		return 'Counter';
	}
	
	//-----------------
	//Setup
	
	beforeEach() {
		//Called before each test for test setup (if needed)
		//Construct a unit model for testing (we use ivar "unit")
		super.beforeEach();
		//framework - name of model class here (and using the constructor that is available)
		this.unit = new Counter();
	}
	
	//-----------------
	//Tests
	
	testConstruction() {
		//Initially we expect count to be 0
		this.assertEquals(0, this.unit.getCount());
	}
	
	testIncrement() {
		const counter = this.unit;
		counter.increment();
		counter.increment();
		this.assertEquals(2, counter.getCount());
	}
	
	testDecrement() {
		const counter = this.unit;
		counter.decrement();
		counter.decrement();
		this.assertEquals(-2, counter.getCount());
	}
	
	
}