getters.js
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getters.js
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	import { test, summary } from './helpers.js';

	console.log('Getter/Setter Tests\n');

	let obj1 = {
	get value() {
	return 42;
	}
	};
	test('basic getter', obj1.value, 42);

	let obj2 = {
	_count: 0,
	get count() {
	return this._count;
	},
	set count(val) {
	this._count = val;
	}
	};
	test('getter initial value', obj2.count, 0);
	obj2.count = 10;
	test('setter updates value', obj2.count, 10);

	let obj3 = {
	firstName: 'John',
	lastName: 'Doe',
	get fullName() {
	return this.firstName + ' ' + this.lastName;
	}
	};
	test('computed getter', obj3.fullName, 'John Doe');

	let obj4 = {
	get 'special-key'() {
	return 'special';
	}
	};
	test('string key getter', obj4['special-key'], 'special');

	let obj5 = {
	get 0() {
	return 'zero';
	}
	};
	test('number key getter', obj5[0], 'zero');

	let obj6 = {
	_x: 0,
	_y: 0,
	get x() {
	return this._x;
	},
	set x(v) {
	this._x = v;
	},
	get y() {
	return this._y;
	},
	set y(v) {
	this._y = v;
	}
	};
	obj6.x = 5;
	obj6.y = 10;
	test('multiple getters x', obj6.x, 5);
	test('multiple getters y', obj6.y, 10);

	let obj7 = {
	get data() {
	return { a: 1, b: 2 };
	}
	};
	test('getter returns object', obj7.data.a, 1);

	let obj8 = {
	_age: 0,
	get age() {
	return this._age;
	},
	set age(val) {
	if (val < 0) val = 0;
	this._age = val;
	}
	};
	obj8.age = -5;
	test('setter validation', obj8.age, 0);
	obj8.age = 25;
	test('setter valid value', obj8.age, 25);

	let obj9 = {
	get readonly() {
	return 'constant';
	}
	};
	test('getter-only read', obj9.readonly, 'constant');
	obj9.readonly = 'changed';
	test('getter-only unchanged', obj9.readonly, 'constant');

	let strictError = (function () {
	'use strict';
	try {
	let strictObj = {
	get x() {
	return 1;
	}
	};
	strictObj.x = 2;
	return false;
	} catch (e) {
	return e instanceof TypeError;
	}
	})();
	test('strict mode getter-only throws', strictError, true);

	let obj10 = {
	multiplier: 3,
	_value: 7,
	get computed() {
	return this._value * this.multiplier;
	}
	};
	test('getter with this', obj10.computed, 21);

	let sideEffect = 0;
	let obj11 = {
	set trigger(val) {
	sideEffect = val * 2;
	}
	};
	obj11.trigger = 5;
	test('setter side effect', sideEffect, 10);

	summary();

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