zrequire('user_pill');
zrequire('settings_user_groups');

set_global('$', global.make_zjquery());
set_global('i18n', global.stub_i18n);
set_global('confirm_dialog', {});

const Dict = zrequire('dict').Dict;

const noop = function () {};

const pills = {
    pill: {},
};

let create_item_handler;

set_global('channel', {});
set_global('blueslip', global.make_zblueslip());
set_global('typeahead_helper', {});
set_global('user_groups', {
    get_user_group_from_id: noop,
    remove: noop,
    add: noop,
});
set_global('ui_report', {});
set_global('people', {
    my_current_user_id: noop,
    small_avatar_url_for_person: function () {
        return 'http://example.com/example.png';
    },
});
set_global('page_params', {});

function reset_test_setup(pill_container_stub) {
    function input_pill_stub(opts) {
        assert.equal(opts.container, pill_container_stub);
        create_item_handler = opts.create_item_from_text;
        assert(create_item_handler);
        return pills;
    }
    set_global('input_pill', {
        create: input_pill_stub,
    });
}

run_test('can_edit', () => {
    page_params.is_guest = false;
    page_params.is_admin = true;
    assert(settings_user_groups.can_edit(1));

    page_params.is_admin = false;
    page_params.is_guest = true;
    assert(!settings_user_groups.can_edit(1));

    page_params.is_guest = false;
    page_params.is_admin = false;
    user_groups.is_member_of = (group_id, user_id) => {
        assert.equal(group_id, 1);
        assert.equal(user_id, undefined);
        return false;
    };
    assert(!settings_user_groups.can_edit(1));

    page_params.realm_user_group_edit_policy = 2;
    page_params.is_admin = true;
    assert(settings_user_groups.can_edit(1));

    page_params.is_admin = false;
    user_groups.is_member_of = (group_id, user_id) => {
        assert.equal(group_id, 1);
        assert.equal(user_id, undefined);
        return true;
    };
    assert(!settings_user_groups.can_edit(1));

    page_params.realm_user_group_edit_policy = 1;
    page_params.is_admin = false;
    user_groups.is_member_of = (group_id, user_id) => {
        assert.equal(group_id, 1);
        assert.equal(user_id, undefined);
        return true;
    };
    assert(settings_user_groups.can_edit(1));

});

const user_group_selector = "#user-groups #1";
const cancel_selector = "#user-groups #1 .save-status.btn-danger";
const saved_selector = "#user-groups #1 .save-status.sea-green";
const name_selector = "#user-groups #1 .name";
const description_selector = "#user-groups #1 .description";
const instructions_selector = "#user-groups #1 .save-instructions";

run_test('populate_user_groups', () => {
    const realm_user_group = {
        id: 1,
        name: 'Mobile',
        description: 'All mobile people',
        members: Dict.from_array([2, 4]),
    };
    const iago = {
        email: 'iago@zulip.com',
        user_id: 2,
        full_name: 'Iago',
    };
    const alice = {
        email: 'alice@example.com',
        user_id: 31,
        full_name: 'Alice',
    };
    const bob = {
        email: 'bob@example.com',
        user_id: 32,
        full_name: 'Bob',
    };

    people.get_realm_persons = function () {
        return [iago, alice, bob];
    };

    user_groups.get_realm_user_groups = function () {
        return [realm_user_group];
    };

    let templates_render_called = false;
    const fake_rendered_temp = $.create('fake_admin_user_group_list_template_rendered');
    global.stub_templates(function (template, args) {
        assert.equal(template, 'admin_user_group_list');
        assert.equal(args.user_group.id, 1);
        assert.equal(args.user_group.name, 'Mobile');
        assert.equal(args.user_group.description, 'All mobile people');
        templates_render_called = true;
        return fake_rendered_temp;
    });

    let user_groups_list_append_called = false;
    $('#user-groups').append = function (rendered_temp) {
        assert.equal(rendered_temp, fake_rendered_temp);
        user_groups_list_append_called = true;
    };

    let get_person_from_user_id_called = false;
    people.get_person_from_user_id = function (user_id) {
        if (user_id === iago.user_id) {
            return iago;
        }
        if (user_id === undefined) {
            return noop;
        }
        assert.equal(user_id, 4);
        blueslip.set_test_data('warn', 'Undefined user in function append_user');
        get_person_from_user_id_called = true;
    };

    settings_user_groups.can_edit = function () {
        return true;
    };

    const all_pills = {};

    const pill_container_stub = $('.pill-container[data-group-pills="1"]');
    pills.appendValidatedData = function (item) {
        const id = item.user_id;
        assert.equal(all_pills[id], undefined);
        all_pills[id] = item;
    };
    pills.items = function () {
        return _.values(all_pills);
    };

    let text_cleared;
    pills.clear_text = function () {
        text_cleared = true;
    };

    const input_field_stub = $.create('fake-input-field');
    pill_container_stub.children = function () {
        return input_field_stub;
    };

    let input_typeahead_called = false;
    input_field_stub.typeahead = function (config) {
        assert.equal(config.items, 5);
        assert(config.fixed);
        assert(config.dropup);
        assert(config.stopAdvance);
        assert.equal(typeof config.source, 'function');
        assert.equal(typeof config.highlighter, 'function');
        assert.equal(typeof config.matcher, 'function');
        assert.equal(typeof config.sorter, 'function');
        assert.equal(typeof config.updater, 'function');

        (function test_highlighter() {
            const fake_person = $.create('fake-person');
            typeahead_helper.render_person = function () {
                return fake_person;
            };
            assert.equal(config.highlighter(), fake_person);
        }());

        const fake_context = {
            query: 'ali',
        };

        (function test_source() {
            const result = config.source.call(fake_context, iago);
            const emails = _.pluck(result, 'email').sort();
            assert.deepEqual(emails, [alice.email, bob.email]);
        }());

        (function test_matcher() {
            /* Here the query doesn't begin with an '@' because typeahead is triggered
            by the '@' sign and thus removed in the query. */
            let result = config.matcher.call(fake_context, iago);
            assert(!result);

            result = config.matcher.call(fake_context, alice);
            assert(result);
        }());

        (function test_sorter() {
            let sort_recipientbox_typeahead_called = false;
            typeahead_helper.sort_recipientbox_typeahead = function () {
                sort_recipientbox_typeahead_called = true;
            };
            config.sorter.call(fake_context);
            assert(sort_recipientbox_typeahead_called);
        }());

        (function test_updater() {
            input_field_stub.text('@ali');
            user_groups.get_user_group_from_id = function () {
                return realm_user_group;
            };

            let saved_fade_out_called = false;
            let cancel_fade_to_called = false;
            let instructions_fade_to_called = false;
            $(saved_selector).fadeOut = function () {
                saved_fade_out_called = true;
            };
            $(cancel_selector).css = function (data) {
                if (typeof data === 'string') {
                    assert.equal(data, 'display');
                }
                assert.equal(typeof data, 'object');
                assert.equal(data.display, 'inline-block');
                assert.equal(data.opacity, '0');
                return $(cancel_selector);
            };
            $(cancel_selector).fadeTo = function () {
                cancel_fade_to_called = true;
            };
            $(instructions_selector).css = function (data) {
                if (typeof data === 'string') {
                    assert.equal(data, 'display');
                }
                assert.equal(typeof data, 'object');
                assert.equal(data.display, 'block');
                assert.equal(data.opacity, '0');
                return $(instructions_selector);
            };
            $(instructions_selector).fadeTo = function () {
                instructions_fade_to_called = true;
            };

            text_cleared = false;
            config.updater(alice);
            // update_cancel_button is called.
            assert(saved_fade_out_called);
            assert(cancel_fade_to_called);
            assert(instructions_fade_to_called);
            assert.equal(text_cleared, true);
        }());
        input_typeahead_called = true;
    };

    let get_by_email_called = false;
    people.get_by_email = function (user_email) {
        get_by_email_called = true;
        if (user_email === iago.email) {
            return iago;
        }
        if (user_email === bob.email) {
            return bob;
        }
        assert.equal(user_email,
                     'Expected user email to be of Alice or Iago here.');
    };
    pills.onPillCreate = function (handler) {
        assert.equal(typeof handler, 'function');
        handler();
    };

    function test_create_item(handler) {
        (function test_rejection_path() {
            const item = handler(iago.email, pills.items());
            assert(get_by_email_called);
            assert.equal(item, undefined);
        }());

        (function test_success_path() {
            get_by_email_called = false;
            const res = handler(bob.email, pills.items());
            assert(get_by_email_called);
            assert.equal(typeof res, 'object');
            assert.equal(res.user_id, bob.user_id);
            assert.equal(res.display_value, bob.full_name);
        }());
    }

    pills.onPillRemove = function (handler) {
        global.patch_builtin('setTimeout', function (func) {
            func();
        });
        realm_user_group.members = Dict.from_array([2, 31]);
        handler();
    };

    reset_test_setup(pill_container_stub);
    settings_user_groups.set_up();
    assert(templates_render_called);
    assert(user_groups_list_append_called);
    assert(get_person_from_user_id_called);
    assert(input_typeahead_called);
    assert.equal(blueslip.get_test_logs('warn').length, 1);
    blueslip.clear_test_data();
    test_create_item(create_item_handler);

    // Tests for settings_user_groups.set_up workflow.
    assert.equal(typeof $('.organization form.admin-user-group-form').get_on_handler("submit"), 'function');
    assert.equal(typeof $('#user-groups').get_on_handler('click', '.delete'), 'function');
    assert.equal(typeof $('#user-groups').get_on_handler('keypress', '.user-group h4 > span'), 'function');
});
run_test('with_external_user', () => {

    const realm_user_group = {
        id: 1,
        name: 'Mobile',
        description: 'All mobile people',
        members: Dict.from_array([2, 4]),
    };

    user_groups.get_realm_user_groups = function () {
        return [realm_user_group];
    };

    // We return noop because these are already tested, so we skip them
    people.get_realm_persons = function () {
        return noop;
    };

    global.stub_templates(function () {
        return noop;
    });

    people.get_person_from_user_id = function () {
        return noop;
    };

    user_pill.append_person = function () {
        return noop;
    };

    let can_edit_called = 0;
    settings_user_groups.can_edit = function () {
        can_edit_called += 1;
        return false;
    };

    // Reset zjquery to test stuff with user who cannot edit
    set_global('$', global.make_zjquery());

    let user_group_find_called = 0;
    const user_group_stub = $('div.user-group[id="1"]');
    const name_field_stub = $.create('fake-name-field');
    const description_field_stub = $.create('fake-description-field');
    const input_stub = $.create('fake-input');
    user_group_stub.find = function (elem) {
        if (elem === '.name') {
            user_group_find_called += 1;
            return name_field_stub;
        }
        if (elem === '.description') {
            user_group_find_called += 1;
            return description_field_stub;
        }
    };

    const pill_container_stub = $('.pill-container[data-group-pills="1"]');
    const pill_stub = $.create('fake-pill');
    let pill_container_find_called = 0;
    pill_container_stub.find = function (elem) {
        if (elem === '.input') {
            pill_container_find_called += 1;
            return input_stub;
        }
        if (elem === '.pill') {
            pill_container_find_called += 1;
            return pill_stub;
        }
    };

    input_stub.css = function (property, val) {
        assert.equal(property, 'display');
        assert.equal(val, 'none');
    };

    // Test the 'off' handlers on the pill-container
    const turned_off = {};
    pill_container_stub.off = function (event_name, sel) {
        if (sel === undefined) {
            sel = 'whole';
        }
        turned_off[event_name + '/' + sel] = true;
    };

    let pill_hover_called = false;
    let callback;
    let empty_fn;
    pill_stub.hover = function (one, two) {
        callback = one;
        empty_fn = two;
        pill_hover_called = true;
        assert.equal(typeof one, 'function');
        assert.equal(typeof two, 'function');
    };

    const exit_button = $.create('fake-pill-exit');
    pill_stub.set_find_results('.exit', exit_button);
    let exit_button_called = false;
    exit_button.css = function (property, value) {
        exit_button_called = true;
        assert.equal(property, 'opacity');
        assert.equal(value, '0.5');
    };

    // We return noop because these are already tested, so we skip them
    pill_container_stub.children = function () {
        return noop;
    };

    $('#user-groups').append = function () {
        return noop;
    };

    reset_test_setup(pill_container_stub);

    settings_user_groups.set_up();

    let set_parents_result_called = 0;
    let set_attributes_called = 0;

    // Test different handlers with an external user
    const delete_handler = $('#user-groups').get_on_handler('click', '.delete');
    const fake_delete = $.create('fk-#user-groups.delete_btn');
    fake_delete.set_parents_result('.user-group', $('.user-group'));
    set_parents_result_called += 1;
    $('.user-group').attr('id', '1');
    set_attributes_called += 1;

    const name_update_handler = $(user_group_selector).get_on_handler("input", ".name");

    const des_update_handler = $(user_group_selector).get_on_handler("input", ".description");

    const member_change_handler = $(user_group_selector).get_on_handler("blur", ".input");

    const name_change_handler = $(user_group_selector).get_on_handler("blur", ".name");

    const des_change_handler = $(user_group_selector).get_on_handler("blur", ".description");

    const event = {
        stopPropagation: noop,
    };
    let pill_click_called = false;
    const pill_click_handler = pill_container_stub.get_on_handler('click');
    pill_click_called = true;

    assert(callback);
    assert(empty_fn);
    callback();
    empty_fn();
    pill_click_handler(event);
    assert.equal(delete_handler.call(fake_delete), undefined);
    assert.equal(name_update_handler(), undefined);
    assert.equal(des_update_handler(), undefined);
    assert.equal(member_change_handler(), undefined);
    assert.equal(name_change_handler(), undefined);
    assert.equal(des_change_handler(), undefined);
    assert.equal(set_parents_result_called, 1);
    assert.equal(set_attributes_called, 1);
    assert.equal(can_edit_called, 9);
    assert(exit_button_called);
    assert(pill_click_called);
    assert(pill_hover_called);
    assert.equal(user_group_find_called, 2);
    assert.equal(pill_container_find_called, 4);
    assert.equal(turned_off['keydown/.pill'], true);
    assert.equal(turned_off['keydown/.input'], true);
    assert.equal(turned_off['click/whole'], true);
});

run_test('reload', () => {
    $('#user-groups').html('Some text');
    let populate_user_groups_called = false;
    settings_user_groups.populate_user_groups = function () {
        populate_user_groups_called = true;
    };
    settings_user_groups.reload();
    assert(populate_user_groups_called);
    assert.equal($('#user-groups').html(), '');
});

run_test('reset', () => {
    settings_user_groups.reset();
    const result = settings_user_groups.reload();
    assert.equal(result, undefined);
});

run_test('on_events', () => {

    settings_user_groups.can_edit = function () {
        return true;
    };

    (function test_admin_user_group_form_submit_triggered() {
        const handler = $('.organization form.admin-user-group-form').get_on_handler("submit");
        const event = {
            stopPropagation: noop,
            preventDefault: noop,
        };
        const fake_this = $.create('fake-form.admin-user-group-form');
        const fake_object_array = [{
            name: 'fake-name',
            value: '',
        }, {
            name: 'fake-name',
            value: 'fake-value',
        }];
        fake_this.serializeArray = function () {
            return fake_object_array;
        };
        channel.post = function (opts) {
            const data = {
                members: '[null]',
            };
            data[fake_object_array[1].name] = fake_object_array[1].value;
            assert.equal(opts.url, "/json/user_groups/create");
            assert.deepEqual(opts.data, data);

            (function test_post_success() {
                $('#admin-user-group-status').show();
                $("form.admin-user-group-form input[type='text']").val('fake-content');
                ui_report.success = function (text, ele) {
                    assert.equal(text, 'translated: User group added!');
                    assert.equal(ele, $('#admin-user-group-status'));
                };

                opts.success();

                assert(!$('#admin-user-group-status').visible());
                assert.equal($("form.admin-user-group-form input[type='text']").val(), '');
            }());

            (function test_post_error() {
                $('#admin-user-group-status').show();
                ui_report.error = function (error_msg, error_obj, ele) {
                    const xhr = {
                        responseText: '{"msg":"fake-msg"}',
                    };
                    assert.equal(error_msg, 'translated: Failed');
                    assert.deepEqual(error_obj, xhr);
                    assert.equal(ele, $('#admin-user-group-status'));
                };
                const xhr = {
                    responseText: '{"msg":"fake-msg", "attrib":"val"}',
                };
                opts.error(xhr);

                assert(!$('#admin-user-group-status').visible());
            }());
        };

        handler.call(fake_this, event);
    }());

    (function test_user_groups_delete_click_triggered() {
        const handler = $('#user-groups').get_on_handler("click", ".delete");
        const fake_this = $.create('fake-#user-groups.delete_btn');
        fake_this.set_parents_result('.user-group', $('.user-group'));
        $('.user-group').attr('id', '1');

        channel.del = function (opts) {
            const data = {
                id: 1,
            };
            let settings_user_groups_reload_called = false;
            assert.equal(opts.url, "/json/user_groups/1");
            assert.deepEqual(opts.data, data);

            settings_user_groups.reload = function () {
                settings_user_groups_reload_called = true;
            };
            opts.success();
            assert(settings_user_groups_reload_called);

            fake_this.text(i18n.t('fake-text'));
            opts.error();
            assert.equal(fake_this.text(), 'translated: Failed!');
        };

        confirm_dialog.launch = (conf) => {
            conf.on_click();
        };

        handler.call(fake_this);
    }());

    (function test_user_groups_keypress_enter_triggered() {
        const handler = $('#user-groups').get_on_handler("keypress", ".user-group h4 > span");
        let default_action_for_enter_stopped = false;
        const event = {
            which: 13,
            preventDefault: function () {
                default_action_for_enter_stopped = true;
            },
        };
        handler(event);
        assert(default_action_for_enter_stopped);
    }());

    (function test_do_not_blur() {
        const blur_event_classes = [".name", ".description", ".input"];
        let api_endpoint_called = false;
        channel.post = function () {
            api_endpoint_called = true;
        };
        channel.patch = noop;
        const fake_this = $.create('fake-#user-groups_do_not_blur');
        const event = {
            relatedTarget: fake_this,
        };

        // Any of the blur_exceptions trigger blur event.
        _.each(blur_event_classes, function (class_name) {
            const handler = $(user_group_selector).get_on_handler("blur", class_name);
            const blur_exceptions = _.without([".pill-container", ".name", ".description", ".input", ".delete"],
                                              class_name);
            _.each(blur_exceptions, function (blur_exception) {
                api_endpoint_called = false;
                fake_this.closest = function (class_name) {
                    if (class_name === blur_exception || class_name === user_group_selector) {
                        return [1];
                    }
                    return [];
                };
                handler.call(fake_this, event);
                assert(!api_endpoint_called);
            });

            api_endpoint_called = false;
            fake_this.closest = function (class_name) {
                if (class_name === ".typeahead") {
                    return [1];
                }
                return [];
            };
            handler.call(fake_this, event);
            assert(!api_endpoint_called);

            // Cancel button triggers blur event.
            let settings_user_groups_reload_called = false;
            settings_user_groups.reload = function () {
                settings_user_groups_reload_called = true;
            };
            api_endpoint_called = false;
            fake_this.closest = function (class_name) {
                if (class_name === ".save-status.btn-danger" || class_name === user_group_selector) {
                    return [1];
                }
                return [];
            };
            handler.call(fake_this, event);
            assert(!api_endpoint_called);
            assert(settings_user_groups_reload_called);
        });

    }());

    (function test_update_cancel_button() {
        const handler_name = $(user_group_selector).get_on_handler("input", ".name");
        const handler_desc = $(user_group_selector).get_on_handler("input", ".description");
        const sib_des = $(description_selector);
        const sib_name = $(name_selector);
        sib_name.text(i18n.t('mobile'));
        sib_des.text(i18n.t('All mobile members'));

        const group_data = {
            name: 'translated: mobile',
            description: 'translated: All mobile members',
            members: Dict.from_array([2, 31])};
        user_groups.get_user_group_from_id = function () {
            return group_data;
        };

        let cancel_fade_out_called = false;
        let instructions_fade_out_called = false;
        $(cancel_selector).show();
        $(cancel_selector).fadeOut = function () {
            cancel_fade_out_called = true;
        };
        $(instructions_selector).fadeOut = function () {
            instructions_fade_out_called = true;
        };

        // Cancel button removed if user group if user group has no changes.
        const fake_this = $.create('fake-#update_cancel_button');
        handler_name.call(fake_this);
        assert(cancel_fade_out_called);
        assert(instructions_fade_out_called);

        // Check if cancel button removed if user group error is showing.
        $(user_group_selector + ' .user-group-status').show();
        cancel_fade_out_called = false;
        instructions_fade_out_called = false;
        handler_name.call(fake_this);
        assert(cancel_fade_out_called);
        assert(instructions_fade_out_called);

        // Check for handler_desc to achieve 100% coverage.
        cancel_fade_out_called = false;
        instructions_fade_out_called = false;
        handler_desc.call(fake_this);
        assert(cancel_fade_out_called);
        assert(instructions_fade_out_called);
    }());

    (function test_user_groups_save_group_changes_triggered() {
        const handler_name = $(user_group_selector).get_on_handler("blur", ".name");
        const handler_desc = $(user_group_selector).get_on_handler("blur", ".description");
        const sib_des = $(description_selector);
        const sib_name = $(name_selector);
        sib_name.text(i18n.t('mobile'));
        sib_des.text(i18n.t('All mobile members'));

        const group_data = {members: Dict.from_array([2, 31])};
        user_groups.get_user_group_from_id = function () {
            return group_data;
        };
        let api_endpoint_called = false;
        let cancel_fade_out_called = false;
        let saved_fade_to_called = false;
        let instructions_fade_out_called = false;
        $(instructions_selector).fadeOut = function () {
            instructions_fade_out_called = true;
        };
        $(cancel_selector).fadeOut = function () {
            cancel_fade_out_called = true;
        };
        $(saved_selector).css = function (data) {
            if (typeof data === 'string') {
                assert.equal(data, 'display');
            }
            assert.equal(typeof data, 'object');
            assert.equal(data.display, 'inline-block');
            assert.equal(data.opacity, '0');
            return $(saved_selector);
        };
        $(saved_selector).fadeTo = function () {
            saved_fade_to_called = true;
            return $(saved_selector);
        };

        channel.patch = function (opts) {
            assert.equal(opts.url, "/json/user_groups/1");
            assert.equal(opts.data.name, 'translated: mobile');
            assert.equal(opts.data.description, 'translated: All mobile members');
            api_endpoint_called = true;
            (function test_post_success() {
                global.patch_builtin('setTimeout', function (func) {
                    func();
                });
                opts.success();
                assert(cancel_fade_out_called);
                assert(instructions_fade_out_called);
                assert(saved_fade_to_called);
            }());
            (function test_post_error() {
                const user_group_error = $(user_group_selector + ' .user-group-status');
                user_group_error.show();
                ui_report.error = function (error_msg, error_obj, ele) {
                    const xhr = {
                        responseText: '{"msg":"fake-msg"}',
                    };
                    assert.equal(error_msg, 'translated: Failed');
                    assert.deepEqual(error_obj, xhr);
                    assert.equal(ele, user_group_error);
                };
                const xhr = {
                    responseText: '{"msg":"fake-msg", "attrib":"val"}',
                };
                opts.error(xhr);

                assert(user_group_error.visible());
            }());
        };

        const fake_this = $.create('fake-#user-groups_blur_name');
        fake_this.closest = function () {
            return [];
        };
        fake_this.set_parents_result(user_group_selector, $(user_group_selector));
        const event = {
            relatedTarget: fake_this,
        };

        api_endpoint_called = false;
        handler_name.call(fake_this, event);
        assert(api_endpoint_called);

        // Check API endpoint isn't called if name and desc haven't changed.
        group_data.name = "translated: mobile";
        group_data.description = "translated: All mobile members";
        api_endpoint_called = false;
        handler_name.call(fake_this, event);
        assert(!api_endpoint_called);

        // Check for handler_desc to achieve 100% coverage.
        api_endpoint_called = false;
        handler_desc.call(fake_this, event);
        assert(!api_endpoint_called);
    }());

    (function test_user_groups_save_member_changes_triggered() {
        const handler = $(user_group_selector).get_on_handler("blur", ".input");
        const realm_user_group = {
            id: 1,
            name: 'Mobile',
            description: 'All mobile people',
            members: Dict.from_array([2, 4]),
        };

        user_groups.get_user_group_from_id = function (id) {
            assert.equal(id, 1);
            return realm_user_group;
        };

        let cancel_fade_out_called = false;
        let saved_fade_to_called = false;
        let instructions_fade_out_called = false;
        $(instructions_selector).fadeOut = function () {
            instructions_fade_out_called = true;
        };
        $(cancel_selector).fadeOut = function () {
            cancel_fade_out_called = true;
        };
        $(saved_selector).css = function () {
            return $(saved_selector);
        };
        $(saved_selector).fadeTo = function () {
            saved_fade_to_called = true;
            return $(saved_selector);
        };

        let api_endpoint_called = false;
        channel.post = function (opts) {
            assert.equal(opts.url, "/json/user_groups/1/members");
            assert.equal(opts.data.add, '[31]');
            assert.equal(opts.data.delete, '[4]');
            api_endpoint_called = true;

            (function test_post_success() {
                opts.success();
                assert(cancel_fade_out_called);
                assert(instructions_fade_out_called);
                assert(saved_fade_to_called);
            }());
        };

        const fake_this = $.create('fake-#user-groups_blur_input');
        fake_this.set_parents_result(user_group_selector, $(user_group_selector));
        fake_this.closest = function () {
            return [];
        };
        const event = {
            relatedTarget: fake_this,
        };

        api_endpoint_called = false;
        handler.call(fake_this, event);
        assert(api_endpoint_called);
    }());
});