make-arrow-function/test/index.js

Function that returns an arbitrary arrow function, or undefined if arrow function syntax is unsupported.

'use strict';

var test = require('tape');
var makeArrowFunction = require('../');

test('makeArrowFunction() is undefined or an arrow function', function (t) {
	var arrowFunction = makeArrowFunction();
	if (arrowFunction) {
		t.equal(typeof arrowFunction, 'function', 'makeArrowFunction is function');
		t.equal(String(arrowFunction), '(a, b) => a * b', 'arrowFunction has expected source');
	} else {
		t.equal(typeof arrowFunction, 'undefined', 'makeArrowFunction is undefined');
	}
	t.end();
});

test('makeArrowFunction.list() is an array', function (t) {
	var funcs = makeArrowFunction.list();
	var expectedSources = [
		'(a, b) => a * b',
		'() => 42',
		'() => function () {}',
		'() => x => x * x',
		'y => x => x * x',
		'x => x * x',
		'x => { return x * x; }',
		'(x, y) => { return x + x; }',
		'(a = Math.random(10)) => {}',
		'(a = function() {\n\tif (Math.random() < 0.5) { return 42; }\n\treturn "something else";\n}) => a()'
	];
	t.plan(1 + (2 * funcs.length));
	t.equal(Object.prototype.toString.call(funcs), '[object Array]', 'list() is an array');
	if (funcs.length === 0) {
		t.comment('no arrow functions present');
	} else {
		for (var i = 0; i < funcs.length; ++i) {
			t.equal(typeof funcs[i], 'function', funcs[i] + ' is a function');
			t.equal(String(funcs[i]), expectedSources[i], '"' + funcs[i] + '" !== "' + expectedSources[i] + '"');
		}
	}
	t.end();
});