Closed mschaaf closed 4 years ago
Could you update to the current version of Cypress and let me know if this is still happening for you? Your issue may have already been fixed as I know we addressed an issue similar to this.
Faced the same problem with latest version 3.8.1 on React SPA,
cy.get('.some-css-class').then(($el) => {
console.log(Cypress.dom.isDetached($el)) // false
}).click();
Initially cy.get() is able to find the element, in-between React kicks rendering cycle and click() is not able to see the reference of the element. Any clue ?
@jennifer-shehane Faced the same issue with the latest version 3.8.1. Can you take a look at it. It blocked me for a while.
cy.get('#wact_rct_39').trigger('mouseover','bottom')
.trigger('mousedown','bottom', {force: true}).wait(300)
.trigger('mousemove', { clientX: 200, clientY: 630 })
.trigger('mouseup', {force: true})
After trigger mousedown, there is a XHR request and then when execute mousemove, then error show on page.
Not sure if it's helpful at all, but I found the error docs for this error quite enlightening and helpful. I literally fixed it by heeding the recommendations.
I'm sure your selectors will be different, but here's the diff that fixed my same issue:
When I read the docs it talked about how frameworks will mount/unmount behind the scenes in a way that's not visible to our naked eyes, and that really hit home. We too are using React. But probably would be same issue for Angular, Ember, etc., maybe.
Finding a way to simplify and break apart my query's made the tests pass for this one.
Hope it's somehow helpful even if pretty high level and hand wavy :)
Yes, please read the recommendations from the error message for this error here: https://on.cypress.io/error-messages#cy-failed-because-the-element-you-are-chaining-off-of-has-become-detached-or-removed-from-the-dom
There's not much Cypress can do with an element that no longer exists in the DOM, so you will need to restructure your tests to account for this is your framework mounts/unmounts DOM elements.
@jennifer-shehane Please read the description of the issue. I wrote that we followed the advice and it didn't solve the issue. So if you close the issue I expect from you that you can show me where we didn't follow this advice. Thank you.
The comment from @roblevintennis seems unrelated and closing the issue because of it is wrong IMO.
having the same issue
same issue, the element does exist on the dom, but cannot find it. It works well in local, but fails in CI.
@jennifer-shehane I think it's really sad that this was closed. Cypress docs mention in so many places how important it is to have tests not be flaky, and in this case a very simple cy.get('button').click()
gets very flaky just because you use e.g. React.
Frameworks like React might chose to re-render buttons for various reasons, and you even acknowledged this in your error message "Common situations why this happens: - Your JS framework re-rendered asynchronously" but then you fail to provide a solution for this situation, let me explain:
The reasons for a re-render can be many, and e.g. occur in a completely different feature on the same page, while it is still loading or running animations. And in your conditional testing guide you write yourself:
To do this would require you to know with 100% guarantee that your application has finished all asynchronous rendering and that there are no pending network requests, setTimeouts, intervals, postMessage, or async/await code.
This is difficult to do (if not impossible) without making changes to your application. You could use a library like Zone.js, but even that does not capture every async possibility.
So I think your proposed solutions "Re-query for newly added DOM elements" or "Guard Cypress from running commands until a specific condition is met" will fall short for a reasonably complex application. In fact I ran into this problem on a big SPA with dozens of developers working on it, and some component from another team finishes loading in the middle of our test.
To solve the problem I think Cypress should just re-try and look for a new button that matches the selector. Or there should be at least a simple example code snippet on how to solve the generic problem of having a framework re-render between selector and click.
Following because we are having the same issue. Hoping this gets reopened and resolved. As with @leogoesger, our tests pass every time locally but fail on CI intermittently
The same problem with SPA on AngulaJS.
Faced this issue on 3.8.0 with React
If anyone is encountering this issue with .click(), I found that .click({force: true})
circumvented the problem in my case.
I'm using Angular 9 and encountered the issue when trying to access a menu item of a Mat Menu (angular material) component.
The menu rendering is all js, so I would not be surprised if the issue resulted from some tricky re-rendering behavior. I first tried to simplify the command (removing commands between the .get() and .click(), as suggested in the simplified example in the docs) but that didn't seem to help, in the end I was still seeing the issue with just cy.get(.my-class-name).click()
; as with other posters, the test runner showed get() logging the expected element, but click() failed with the detached element issue.
Faced this issue on 3.8.0 with React
Found some possible solution / workaround, which helped in my case: I had an element, which after some events would get an id attribute (I didn't notice that) and cypress somehow was trying to interact with the element without that id attribute (contains, should etc would fail) - thanks to cypress ui. The only thing helped was to use invoke and then do other actions after a check on the id
I think @egretsRegrets suggestion of using { force: true }
is the key here. To Cypress, the button may appear to be detached from the DOM (because of re-rendering) but from the user perspective they still have the ability to click the button (at least in my particular case).
When using { force: true }
Cypress will skip the check that ensures it is attached to the DOM. See docs.
Just for the record. I think it's absolutely insane that the last version of Cypress that actually works for us is 3.4. How is it possible that this flow is completely broken on newer version of Cypress?
Why doesn't Cypress just re-query the element if it finds it detached? That's literally what it does for every other form of 'get' and apparently did previously.
@Aeolun We're open to PRs to implement this retry mechanism. That would be a pretty large change to our current implementation. I've opened an issue requesting this feature here: https://github.com/cypress-io/cypress/issues/7306
I had a problem similar to what @chopraapooja described. The following solved it for me.
/**
* getAttached(selector)
* getAttached(selectorFn)
*
* Waits until the selector finds an attached element, then yields it (wrapped).
* selectorFn, if provided, is passed $(document). Don't use cy methods inside selectorFn.
*/
Cypress.Commands.add("getAttached", selector => {
const getElement = typeof selector === "function" ? selector : $d => $d.find(selector);
let $el = null;
return cy.document().should($d => {
$el = getElement(Cypress.$($d));
expect(Cypress.dom.isDetached($el)).to.be.false;
}).then(() => cy.wrap($el));
});
This works because cy.should
retries, and the element is re-queried each time.
Example usage:
cy.getAttached("button").click();
cy.getAttached($d => $d.find("button")).click();
The second form lets you use arbitrary logic for finding the element.
Thanks you @wintonpc, your solution nearly fixed the issue I have been experiencing. The only addition that I needed to make for an Ember app was to add an optional contains
parameter to the getAttached
method. And then I added a second expectation:
expect($el).to.contain(contains)
That way, I was able to call getAttached()
and pass in expected text. This replaced my faulty cy.get().should().click()
chain that would always fail on the should()
for a DOM element that was occasionally detaching and reattaching after Cypress entered a search query and the DOM was updated, potentially multiple times, before clicking.
@wintonpc Could we say this is 100% working solution? I've tried your approach and still getting the 'detach from the DOM' :(
@wintonpc Could we say this is 100% working solution? I've tried your approach and still getting the 'detach from the DOM' :(
Same here. We tried the getAttached
solution but it didn't work for us. It seems that the element is detached between the check and the click which suggests that it happens very quickly.
The only workaround for us is a cy.wait(50)
.
@mikepetrusenko I don't think there's a single solution that will work 100% of the time for all applications. What we're really trying to do is wait for the app to complete its DOM updates; waiting for a particular element to be attached is just one way to do that. For my particular app, it worked. For others, it might not. To have rock-solid tests, you're going to need a good understanding of how your app and the framework it uses (Vue.js, React, etc.) work together to update the DOM.
In @czo02 's case, getAttached
failed because it couldn't tell the difference between "still attached" and "newly attached".
Here's another approach that might be more reliable. The following command waits for Vue to stop updating the DOM. If the specified number of milliseconds elapse without any new updates, it considers the updates to have completed.
Cypress command:
Cypress.Commands.add("waitForVue", millis => {
millis = millis || 100;
let startTime = null;
return cy.window().should(w => {
startTime = startTime || Date.now();
expect(Date.now()).to.be.greaterThan(Math.max(startTime, w.lastVueUpdate || startTime) + millis);
});
});
Vue hook (in the app under test):
updated() {
if (window.Cypress) // we're being tested
this.$nextTick(() => window.lastVueUpdate = Date.now());
}
Usage:
cy.get("button:contains(Show Test Button)"); // triggers DOM update
cy.waitForVue(100);
cy.get("button:contains(Test)").click();
I'm not familiar with frameworks other than Vue, but I assume they have similar ways to inform you when updates occur.
The advantage of waitForVue()
over cy.wait()
is that, because it accounts for updates, you can theoretically set a lower timeout for waitForVue()
than you could for cy.wait()
and have them be equally reliable.
@wintonpc Solution didn't work for us, but was the basis for this:
/*
React elements may get detached between when we find them and when .click() is called.
Here we use JQuery .click() right after ensuring the element is attached.
Note that we cannot longer use the original cypress .click() API
Adaptation of https://github.com/cypress-io/cypress/issues/5743#issuecomment-650421731
*/
Cypress.Commands.add('clickAttached', { prevSubject: 'element' }, subject => {
cy.wrap(subject).should($el => {
expect(Cypress.dom.isDetached($el)).to.be.false; // Ensure the element is attached
// Using Jquery .click() here so no queuing from cypress side and not chance for the element to detach
$el.click();
});
});
Sadly one cannot override the click command (Cypress.Commands.overwrite('click', ...)
) because this breaks .type()
(see issue).
Agh. I'm experiencing this a lot with the React app I'm testing too. :(
I don't expect this to work for everyone but what improved flakiness for me is a simple assertion:
cy.get(".preview-btn")
.should("be.visible")
.click();
I am using cy.contains('some text') before clicking in the element I need to click. This is the only way I got to avoid this problem right before clicking in it.
So, it is basically like this:
cy.contains(item) // avoid element detached from the DOM
cy.get(element).click()
This issue will be closed to further comments. Please refer to https://github.com/cypress-io/cypress/issues/7306 for discussion on 'detached from the DOM' strategies and workarounds.
Current behavior:
After upgrade to 3.6.1 from 3.4.1 our cypress tests start to fail for the following constructs.
fails with
We followed the link from the error message and tried to change code to:
But this didn't change the behaviour. Also the element should be visibe from the beginning so not code is changing it in an async way.
Desired behavior:
Should not fail.
Steps to reproduce: (app code and test code)
For now we don't have them because not everytime the same tests fail. The only common thing between them is the same or similar click behavior.
These constructs were not failing with version 3.4.1.
Versions
Ubuntu 19.04 cypress 3.6.1 Electron 73
We run the tests via
yarn cypress run
Any help to find the reason would be appreciated.