Jasmine test cases - "these"

jasmine-these usage example.js

describe("typeof", function() {
	these("expects ", {
		"0 to output number": [ 0, "number" ],
		"NaN to output number": [ NaN, "number" ],
		"undefined to output undefined": [ undefined, "undefined" ],
		"null to output object": [ null, "object" ],
		"Date to output object": [ new Date(), "object" ],
		"{} to output object": [ {}, "object" ],
		"anon function to output object": [ function(){}, "object" ],
	}, function(input, expectedOutput) {
		var actualOutput = typeof input;
		expect(actualOutput).toBe(expectedOutput);
	});
});

jasmine-these.js

// Note: credit goes to William Cowell for creating this extremely helpful test-case runner!

/**
 * Creates a bunch of "it" blocks, one for each test case.
 *
 * @param {String}                 desc - Describes all test cases
 * @param {Object.<string, Array>} testCases
 * @param {String}                 testCases.<key> - Describes each test case
 * @param {Array}                  testCases.<value> - An array of args that will be passed to the test
 * @param {Function(...)}          test - This test will be called once for each test case
 */
function these(desc, testCases, test) {
	_these(it, desc, testCases, test);
}
function xthese(desc, testCases, test) {
	_these(xit, desc, testCases, test);
}
function _these(it, desc, testCases, test) {
	Object.keys(testCases).forEach(function (testCaseName) {
		var testCaseArguments = testCases[testCaseName];

		it(desc + testCaseName, function () {
			test.apply(null, testCaseArguments);
		});
	});
}

In this example, these will generate 7 it blocks, such as
it("expects 0 to output number", ...) and
it("expects NaN to output number", ...).

Each test case will call the test function with the supplied arguments.
Nice, simple, and extraordinarily helpful!!!

Side note: semantically, these is not a good term, because you're not supposed to be describing the test cases.
However, I cannot think of a better term, apart from creating an overload for it.
Ideally, if merged into jasmine, an overload of it would be achievable. But as a "stand alone" utility, these will have to be good enough.