{"action":"opened","issue":{"url":"https://api.github.com/repos/hadley/assertthat/issues/32","labels_url":"https://api.github.com/repos/hadley/assertthat/issues/32/labels{/name}","comments_url":"https://api.github.com/repos/hadley/assertthat/issues/32/comments","events_url":"https://api.github.com/repos/hadley/assertthat/issues/32/events","html_url":"https://github.com/hadley/assertthat/issues/32","id":117472511,"number":32,"title":"\"argument is of length zero\" case uninformative","user":{"login":"archenemies","id":12960503,"avatar_url":"https://avatars.githubusercontent.com/u/12960503?v=3","gravatar_id":"","url":"https://api.github.com/users/archenemies","html_url":"https://github.com/archenemies","followers_url":"https://api.github.com/users/archenemies/followers","following_url":"https://api.github.com/users/archenemies/following{/other_user}","gists_url":"https://api.github.com/users/archenemies/gists{/gist_id}","starred_url":"https://api.github.com/users/archenemies/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/archenemies/subscriptions","organizations_url":"https://api.github.com/users/archenemies/orgs","repos_url":"https://api.github.com/users/archenemies/repos","events_url":"https://api.github.com/users/archenemies/events{/privacy}","received_events_url":"https://api.github.com/users/archenemies/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-11-17T23:07:47Z","updated_at":"2015-11-17T23:07:47Z","closed_at":null,"body":"Hello! I just installed your package. I noticed it does better than 'stopifnot' when comparing to a NULL:\r\n\r\n    > stopifnot(1==NULL) # No error\r\n    > assert_that(1==NULL)\r\n    Error in if (!res) { : argument is of length zero\r\n\r\nThis means that I can use it to check that e.g. `nrow(X)==N`, which is great! However, it gives even prettier errors when the argument is FALSE:\r\n\r\n    > assert_that(1==2)\r\n    Error: 1 not equal to 2\r\n\r\nAre there any plans to, for example, have pretty errors when the argument is of length zero? For example:\r\n\r\n    > assert_that(1==NULL)\r\n    Error in \"1==NULL\" : argument is of length zero\r\n\r\nThis would make it a bit easier to track down the location of the error, although I guess there's always `traceback()`...\r\n"}}