#js #tddjs

namespace.js

(function() {

    var namespaces = {};

    function namespace(string) {

        var object = namespaces;
        var levels = string.split(".");

        if (!(levels[0] in object) && levels[0] in window) {
            throw new Error(levels[0] + " is already defined as a global variable.");
        }

        for (var i in levels) {
            if (typeof object[levels[i]] == "undefined") {
                object[levels[i]] = {};
            }
            object = object[levels[i]];
        }

        window[levels[0]] = namespaces[levels[0]];

        return object;

    }

    window.namespace = namespace;

}())

namespaceTest.js

TestCase("Namespace", {

    setUp: function() {
        delete window.nstest;
    },

    "test sounld create non-existent object": function() {
        namespace("nstest");
        assertObject(nstest);
    },

    "test error should be thrown when the same as global variable is given": function() {
        assertException(namespace.bind(null, "window"), "Error");
    },

    "test sould not overwite existent objects": function() {
        window.nstest = { nested: {} };
        var result = namespace("nstest.nested");
        assertSame(nstest.nested, result);
    },

    "test only create missing parts": function() {
        var existing = {};
        nstest = { nested: { ui: existing } };
        var result = namespace("nstest.nested.ui");
        assertSame(result, nstest.nested.ui);
        assertObject(nstest.nested.ui);
    }

});