如果在NightwatchJS中不存在元素如何在沒有錯誤的情況下停止測試

Question

在我的守夜測試中，每個運行前都有一個運行並從Facebook中刪除應用程序。如果應用程序不存在，我只想停止之前的測試。

.waitForElementPresent('#root div.touchable a', 2000, false, function (result) { 
    if (result.value === false) { 
    browser.saveScreenshot('./test/e2e/img/element-not-there.png') 
    browser.end() 
    } 
}) 
.doSomethingIfElementIsThere() // not real ;) 

即使設置了false參數，這似乎也不起作用。我得到這個錯誤：

ERROR: Unable to locate element: "#root div.touchable a" using: css selector 
    at Object.before (/Users/user/projects/project/test/e2e/specs/testy-mc-test-face.js:30:8) 
✖ Timed out while waiting for element <#root div.touchable a> to be present for 2500 milliseconds. - expected "found" but got: "not found" 
    at Object.before (/Users/user/projects/project/test/e2e/specs/testy-mc-test-face.js:30:8) 

只是想知道如何檢查的東西，而不是錯誤。或者如果元素存在，繼續進行斷言？

的Merci桶

Answer 1

我查了code of the elementPresent assertion：

this.command = function(callback) { 
    return this.api.elements(this.client.locateStrategy, selector, callback); 
}; 

this.value = function(result) { 
    return (result.status !== 0 || result.value.length === 0) ? 'not present' : 'present'; 
}; 

它採用了low-level api，你可以用它來測試元素是否存在：

.elements()

Search for multiple elements on the page, starting from the document root. The located elements will be returned as WebElement JSON objects. First argument to be passed is the locator strategy, which is detailed on the WebDriver docs.

我想該解決方案可看起來像這樣：

browser.elements('css selector', '#root div.touchable a', result => { 
    const isPresent = result.status === 0 && result.value.length > 0; 
    // doStuff 
});