Searching for HTML elements works only on first rootPage in E2E testing

在页面对象中重现 Protractor 的 E2E 流程：导航到根页面，点击 #start-game，然后在 NavController 更改根页面后查询 #goal-wrapper 和浏览器标题。首先检查 GameComponent 显示后浏览器命令会发生什么。完成标准是选择器、等待、getTitle() 和 getSize() 都能在游戏页面上完成。

Hey guys!

I am facing one issue when I try to run E2E tests. I am using Protractor (5.1.2) for E2E tests.
So everything works fine when I try to search for elements on the rootPage. My tests look like this:

game.navigateToRoot();
game.startGame();
game.playTheGame();

Navigation to root works fine, I can normally find the START BUTTON and click on it, which leads me to the GameComponent (I actually change the root like this.nav.setRoot(GameComponent)).
When the game panel is shown, I can not do any HTML selector query, not even (browser.title), because neither one Promise callback is executed. I tried to wait the browser with:

const until = rotractor.ExpectedConditions;
browser.wait(until.presenceOf(game.getFinalResultWrapper()), 5000, 'Element taking too long to appear in the DOM');

Here is my game page object where I make HTML queries:

navigateToRoot() {
    return browser.get('');
}

startGame() {
    const startGameButton = this.getStartGameButton();
    this.getStartGameButton().click();
    // the NavController's root changes
}

getStartGameButton() {
    return $('#start-game');
}

getFinalResultWrapper() {
    return $('.level-complete-wrapper');
}

playTheGame() {
    // nothing works from now on
    const goalWrapper = $('#goal-wrapper');
    const until = protractor.ExpectedConditions;
    browser.wait(until.presenceOf(goalWrapper), 5000, 'Element taking too long to appear in the DOM');
    browser.getTitle().then((title) => {
        console.log('title = ', title);
    });
    $('#goal-wrapper').getSize().then((size) => {
        console.log(size);
    });
}