zulip/frontend_tests/zjsunit/namespace.js

const _ = require('underscore/underscore.js');

let dependencies = [];
const requires = [];
let old_builtins = {};

exports.set_global = function (name, val) {
    global[name] = val;
    dependencies.push(name);
    return val;
};

exports.patch_builtin = function (name, val) {
    old_builtins[name] = global[name];
    global[name] = val;
    return val;
};

exports.zrequire = function (name, fn) {
    if (fn === undefined) {
        fn = '../../static/js/' + name;
    } else if (/^generated\/|^js\/|^shared\/|^third\//.test(fn)) {
        // FIXME: Stealing part of the NPM namespace is confusing.
        fn = '../../static/' + fn;
    }
    delete require.cache[require.resolve(fn)];
    const obj = require(fn);
    requires.push(fn);
    set_global(name, obj);
    return obj;
};

exports.restore = function () {
    dependencies.forEach(function (name) {
        delete global[name];
    });
    requires.forEach(function (fn) {
        delete require.cache[require.resolve(fn)];
    });
    dependencies = [];
    delete global.window.electron_bridge;
    _.extend(global, old_builtins);
    old_builtins = {};
};

exports.stub_out_jquery = function () {
    set_global('$', function () {
        return {
            on: function () {},
            trigger: function () {},
            hide: function () {},
            removeClass: function () {},
        };
    });
    $.fn = {};
    $.now = function () {};
};

exports.with_overrides = function (test_function) {
    // This function calls test_function() and passes in
    // a way to override the namespace temporarily.

    const clobber_callbacks = [];

    const override = function (name, f) {
        const parts = name.split('.');
        const module = parts[0];
        const func_name = parts[1];

        if (!_.has(global, module)) {
            set_global(module, {});
        }

        global[module][func_name] = f;

        clobber_callbacks.push(function () {
            // If you get a failure from this, you probably just
            // need to have your test do its own overrides and
            // not cherry-pick off of the prior test's setup.
            global[module][func_name] =
                'ATTEMPTED TO REUSE OVERRIDDEN VALUE FROM PRIOR TEST';
        });
    };

    test_function(override);

    _.each(clobber_callbacks, function (f) {
        f();
    });
};