range() #js

range.js

TestCase("range", {
    "test of range": function() {
        function range() {
            var s, e, i, j;
            if (2 < arguments.length) {
                s = arguments[0];
                e = arguments[1];
                i = arguments[2];
                if (0 === i) {
                    throw new Error("step must be not zero.");
                }
            } else if (1 < arguments.length) {
                s = arguments[0];
                e = arguments[1];
                i = 1;
            } else if (0 < arguments.length) {
                s = 0;
                e = arguments[0];
                i = 1;
            } else {
                throw new Error("more than 1 arguments is required.");
            }

            var result = [];

            if (0 < i) {
                for (j=s; e>j; j+=i) {
                    result.push(j);
                }
            } else {
                for (j=s; e<j; j+=i) {
                    result.push(j);
                }
            }

            return result;

        }

        assertEquals([1, 2, 3, 4], range(1, 5));
        assertEquals([0, 1, 2, 3], range(0, 4));
        assertEquals([-1, 0], range(-1, 1));
        assertEquals([], range(5, 2));
        assertEquals([5, 4, 3], range(5, 2, -1));
        assertEquals([], range(2, 5, -1));
        assertEquals([0, 1, 2, 3, 4], range(5));
        assertException(range.bind(null, 1, 5, 0), "Error");
    }
});