{"action":"created","issue":{"url":"https://api.github.com/repos/facebook/react/issues/3623","labels_url":"https://api.github.com/repos/facebook/react/issues/3623/labels{/name}","comments_url":"https://api.github.com/repos/facebook/react/issues/3623/comments","events_url":"https://api.github.com/repos/facebook/react/issues/3623/events","html_url":"https://github.com/facebook/react/issues/3623","id":67197082,"number":3623,"title":"ReactCSSTransitionGroup warns when removed while transition in progress","user":{"login":"kassens","id":11849,"avatar_url":"https://avatars.githubusercontent.com/u/11849?v=3","gravatar_id":"","url":"https://api.github.com/users/kassens","html_url":"https://github.com/kassens","followers_url":"https://api.github.com/users/kassens/followers","following_url":"https://api.github.com/users/kassens/following{/other_user}","gists_url":"https://api.github.com/users/kassens/gists{/gist_id}","starred_url":"https://api.github.com/users/kassens/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/kassens/subscriptions","organizations_url":"https://api.github.com/users/kassens/orgs","repos_url":"https://api.github.com/users/kassens/repos","events_url":"https://api.github.com/users/kassens/events{/privacy}","received_events_url":"https://api.github.com/users/kassens/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/facebook/react/labels/Component:%20Addons%20/%20TransitionGroup","name":"Component: Addons / TransitionGroup","color":"fad8c7"},{"url":"https://api.github.com/repos/facebook/react/labels/good%20first%20bug","name":"good first bug","color":"009800"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-04-08T19:05:46Z","updated_at":"2015-04-27T21:56:37Z","closed_at":null,"body":"The [`noEventTimeout` timer](https://github.com/facebook/react/blob/2aeb8a2a6beb00617a4217f7f8284924fa2ad819/src/addons/transitions/ReactCSSTransitionGroupChild.js#L80) is not cleared when a child is unmounted while a transition is in progress. This causes a false positive warning.\r\n"},"comment":{"url":"https://api.github.com/repos/facebook/react/issues/comments/96833241","html_url":"https://github.com/facebook/react/issues/3623#issuecomment-96833241","issue_url":"https://api.github.com/repos/facebook/react/issues/3623","id":96833241,"user":{"login":"sejoker","id":125466,"avatar_url":"https://avatars.githubusercontent.com/u/125466?v=3","gravatar_id":"","url":"https://api.github.com/users/sejoker","html_url":"https://github.com/sejoker","followers_url":"https://api.github.com/users/sejoker/followers","following_url":"https://api.github.com/users/sejoker/following{/other_user}","gists_url":"https://api.github.com/users/sejoker/gists{/gist_id}","starred_url":"https://api.github.com/users/sejoker/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/sejoker/subscriptions","organizations_url":"https://api.github.com/users/sejoker/orgs","repos_url":"https://api.github.com/users/sejoker/repos","events_url":"https://api.github.com/users/sejoker/events{/privacy}","received_events_url":"https://api.github.com/users/sejoker/received_events","type":"User","site_admin":false},"created_at":"2015-04-27T21:56:37Z","updated_at":"2015-04-27T21:56:37Z","body":"@kassens  Could you help me reproduce a bug? I prepared [example](https://jsfiddle.net/sejoker/j9p8xuq6/3/). On click of any item from the list I start the animation for 6 seconds, additionally I output debug info into console. It clearly shows that also warning takes place (5 seconds timeout violated) `componentWillUnmount`  is triggered after `endListener` function executes. It seems to me that a child cannot be unmounted while a transition is in progress (only after) by design. Please correct me if I am wrong."}}